Gutsick Gibbon is the Youtube handle of a biological anthropology PhD
student named Eriks. Two of her recent videos discuss some of the
latest developments relating to the origins of human bipedalism:
<https://www.youtube.com/watch?v=kbQAgPSHbZE>
The above is a link to a 32-minute video where Erika discusses several
papers relating to Sahelanthropus tchadensis. This fossil is
remarkable in part because it's dated to about 7mya and was found in central-african Chad, and also because it may be the oldest bipedal
hominin fossil found to date. However, there appears to be strong disagreement whether the evidence supports bipedalism.
<https://www.youtube.com/watch?v=Nwkfkp360ps>
The above is a link to a 22-minute video where Erika discusses several hypotheses about *why* our ancestors shifted to obligate bipedalism.
She discusses several hypotheses, and presents compelling arguments
for her preferred one.
Gutsick Gibbon is the Youtube handle of a biological anthropology PhD
student named Eriks. Two of her recent videos discuss some of the
latest developments relating to the origins of human bipedalism:
<https://www.youtube.com/watch?v=kbQAgPSHbZE>
The above is a link to a 32-minute video where Erika discusses several
papers relating to Sahelanthropus tchadensis. This fossil is
remarkable in part because it's dated to about 7mya and was found in central-african Chad, and also because it may be the oldest bipedal
hominin fossil found to date. However, there appears to be strong disagreement whether the evidence supports bipedalism.
<https://www.youtube.com/watch?v=Nwkfkp360ps>
The above is a link to a 22-minute video where Erika discusses several hypotheses about *why* our ancestors shifted to obligate bipedalism.
She discusses several hypotheses, and presents compelling arguments
for her preferred one.
On 10/23/22 11:50 PM, jillery wrote:
Gutsick Gibbon is the Youtube handle of a biological anthropology PhD
student named Eriks. Two of her recent videos discuss some of the
latest developments relating to the origins of human bipedalism:
<https://www.youtube.com/watch?v=kbQAgPSHbZE>
The above is a link to a 32-minute video where Erika discusses several
papers relating to Sahelanthropus tchadensis. This fossil is
remarkable in part because it's dated to about 7mya and was found in
central-african Chad, and also because it may be the oldest bipedal
hominin fossil found to date. However, there appears to be strong
disagreement whether the evidence supports bipedalism.
<https://www.youtube.com/watch?v=Nwkfkp360ps>
The above is a link to a 22-minute video where Erika discusses several
hypotheses about *why* our ancestors shifted to obligate bipedalism.
She discusses several hypotheses, and presents compelling arguments
for her preferred one.
I tend to think of it as none of the above.
Simply because it is not that easy to stand upright.
When an animal stands upright you need to solve a problem -
how do you keep from falling over forward and backward.
This might seem simple but it is not because with a four
footed animal the center of gravity forward and backward
is between the front legs and the back legs, and often
that is a greater distance than between the left legs and
the right legs.
Some animals that sort of walk on twos have not solved the
problem - a kangaroo can hop but in general it can not
stably stand. Either way, in essence, the long hand enables
force to be supplied to the far front and far back to counter
falling forward or backward - the forefoot and big toe are
the front force appliers and the heel is the back force
applier. Then of course there are some animals that might
sort of walk on threes (I am thinking of the Jerboa) - but
humans have an extra problem because they have no tail to
possibly act as an extra walking limb, or at least a balance.
On Tue, 25 Oct 2022 01:18:27 -0700, Trolidan7 <Trol...@eternal-september.org> wrote:
On 10/23/22 11:50 PM, jillery wrote:
Gutsick Gibbon is the Youtube handle of a biological anthropology PhD
student named Eriks. Two of her recent videos discuss some of the
latest developments relating to the origins of human bipedalism:
<https://www.youtube.com/watch?v=kbQAgPSHbZE>
The above is a link to a 32-minute video where Erika discusses several
papers relating to Sahelanthropus tchadensis. This fossil is
remarkable in part because it's dated to about 7mya and was found in
central-african Chad, and also because it may be the oldest bipedal
hominin fossil found to date. However, there appears to be strong
disagreement whether the evidence supports bipedalism.
<https://www.youtube.com/watch?v=Nwkfkp360ps>
The above is a link to a 22-minute video where Erika discusses several
hypotheses about *why* our ancestors shifted to obligate bipedalism.
She discusses several hypotheses, and presents compelling arguments
for her preferred one.
I tend to think of it as none of the above.
Simply because it is not that easy to stand upright.
When an animal stands upright you need to solve a problem -
how do you keep from falling over forward and backward.
This might seem simple but it is not because with a fourWatch the cited videos. Erika points out the challenges of going from quadruped to biped, the differences between upright posture and
footed animal the center of gravity forward and backward
is between the front legs and the back legs, and often
that is a greater distance than between the left legs and
the right legs.
bipedalism, and the plausibility of suspensory orthograde posture in
trees as a precursor to bipedalism on the ground.
Some animals that sort of walk on twos have not solved theThat's why humans like big butts, I can not lie.
problem - a kangaroo can hop but in general it can not
stably stand. Either way, in essence, the long hand enables
force to be supplied to the far front and far back to counter
falling forward or backward - the forefoot and big toe are
the front force appliers and the heel is the back force
applier. Then of course there are some animals that might
sort of walk on threes (I am thinking of the Jerboa) - but
humans have an extra problem because they have no tail to
possibly act as an extra walking limb, or at least a balance.
On Tuesday, October 25, 2022 at 6:59:05 PM UTC-4, 69jp...@gmail.com wrote:giant short faced kangaroo, giant ground sloth, running jesus lizard). This primitive mechanical gyroscope was replaced by genetic software improvements enabling reduced body bone weight (esp. femur & occiput), faster & longer bipedal locomotion,
On Tue, 25 Oct 2022 01:18:27 -0700, Trolidan7
<Trol...@eternal-september.org> wrote:
On 10/23/22 11:50 PM, jillery wrote:Watch the cited videos. Erika points out the challenges of going from
Gutsick Gibbon is the Youtube handle of a biological anthropology PhD
student named Eriks. Two of her recent videos discuss some of the
latest developments relating to the origins of human bipedalism:
<https://www.youtube.com/watch?v=kbQAgPSHbZE>
The above is a link to a 32-minute video where Erika discusses several >> >> papers relating to Sahelanthropus tchadensis. This fossil is
remarkable in part because it's dated to about 7mya and was found in
central-african Chad, and also because it may be the oldest bipedal
hominin fossil found to date. However, there appears to be strong
disagreement whether the evidence supports bipedalism.
<https://www.youtube.com/watch?v=Nwkfkp360ps>
The above is a link to a 22-minute video where Erika discusses several >> >> hypotheses about *why* our ancestors shifted to obligate bipedalism.
She discusses several hypotheses, and presents compelling arguments
for her preferred one.
I tend to think of it as none of the above.
Simply because it is not that easy to stand upright.
When an animal stands upright you need to solve a problem -
how do you keep from falling over forward and backward.
This might seem simple but it is not because with a four
footed animal the center of gravity forward and backward
is between the front legs and the back legs, and often
that is a greater distance than between the left legs and
the right legs.
quadruped to biped, the differences between upright posture and
bipedalism, and the plausibility of suspensory orthograde posture in
trees as a precursor to bipedalism on the ground.
Some animals that sort of walk on twos have not solved theThat's why humans like big butts, I can not lie.
problem - a kangaroo can hop but in general it can not
stably stand. Either way, in essence, the long hand enables
force to be supplied to the far front and far back to counter
falling forward or backward - the forefoot and big toe are
the front force appliers and the heel is the back force
applier. Then of course there are some animals that might
sort of walk on threes (I am thinking of the Jerboa) - but
humans have an extra problem because they have no tail to
possibly act as an extra walking limb, or at least a balance.
Bigger butt bones, bigger brain bones, initially.
Homo erectus had unusually thick dense femurs and unusually thick dense occiputs (rear skull bone), which counterbalanced the pace over orthogonal bipedal treks on the ground, substituting for the more typical long dense tail of other bipeds (T rex,
Casually walking while chewing gum, chatting and carrying a squirming child is something only humans could ever do.
On Tue, 25 Oct 2022 16:32:06 -0700 (PDT), Daud Dedengiant short faced kangaroo, giant ground sloth, running jesus lizard). This primitive mechanical gyroscope was replaced by genetic software improvements enabling reduced body bone weight (esp. femur & occiput), faster & longer bipedal locomotion,
<daud....@gmail.com> wrote:
On Tuesday, October 25, 2022 at 6:59:05 PM UTC-4, 69jp...@gmail.com wrote: >> On Tue, 25 Oct 2022 01:18:27 -0700, Trolidan7
<Trol...@eternal-september.org> wrote:
On 10/23/22 11:50 PM, jillery wrote:Watch the cited videos. Erika points out the challenges of going from
Gutsick Gibbon is the Youtube handle of a biological anthropology PhD >> >> student named Eriks. Two of her recent videos discuss some of the
latest developments relating to the origins of human bipedalism:
<https://www.youtube.com/watch?v=kbQAgPSHbZE>
The above is a link to a 32-minute video where Erika discusses several >> >> papers relating to Sahelanthropus tchadensis. This fossil is
remarkable in part because it's dated to about 7mya and was found in >> >> central-african Chad, and also because it may be the oldest bipedal
hominin fossil found to date. However, there appears to be strong
disagreement whether the evidence supports bipedalism.
<https://www.youtube.com/watch?v=Nwkfkp360ps>
The above is a link to a 22-minute video where Erika discusses several >> >> hypotheses about *why* our ancestors shifted to obligate bipedalism. >> >> She discusses several hypotheses, and presents compelling arguments
for her preferred one.
I tend to think of it as none of the above.
Simply because it is not that easy to stand upright.
When an animal stands upright you need to solve a problem -
how do you keep from falling over forward and backward.
This might seem simple but it is not because with a four
footed animal the center of gravity forward and backward
is between the front legs and the back legs, and often
that is a greater distance than between the left legs and
the right legs.
quadruped to biped, the differences between upright posture and
bipedalism, and the plausibility of suspensory orthograde posture in
trees as a precursor to bipedalism on the ground.
Some animals that sort of walk on twos have not solved theThat's why humans like big butts, I can not lie.
problem - a kangaroo can hop but in general it can not
stably stand. Either way, in essence, the long hand enables
force to be supplied to the far front and far back to counter
falling forward or backward - the forefoot and big toe are
the front force appliers and the heel is the back force
applier. Then of course there are some animals that might
sort of walk on threes (I am thinking of the Jerboa) - but
humans have an extra problem because they have no tail to
possibly act as an extra walking limb, or at least a balance.
Bigger butt bones, bigger brain bones, initially.
Homo erectus had unusually thick dense femurs and unusually thick dense occiputs (rear skull bone), which counterbalanced the pace over orthogonal bipedal treks on the ground, substituting for the more typical long dense tail of other bipeds (T rex,
S chadensis was imo not a habitual nor obligate terrestrial orthograde biped, nor a part-time knucklewalking terrestrial quadruped, its foramen magnum reflected a more primitive arboreal orthograde bipedalism associated with suspensory slow brachiation xCasually walking while chewing gum, chatting and carrying a squirming child is something only humans could ever do.@378 cm^3, S. tchadensis' braincase is similar to that of extant
chimpanzees and approximately a third the size of modern human brains.
On Wednesday, October 26, 2022 at 4:10:49 AM UTC-4, 69jp...@gmail.com wrote: >> On Tue, 25 Oct 2022 16:32:06 -0700 (PDT), Daud Dedengiant short faced kangaroo, giant ground sloth, running jesus lizard). This primitive mechanical gyroscope was replaced by genetic software improvements enabling reduced body bone weight (esp. femur & occiput), faster & longer bipedal locomotion,
<daud....@gmail.com> wrote:
On Tuesday, October 25, 2022 at 6:59:05 PM UTC-4, 69jp...@gmail.com wrote: >> >> On Tue, 25 Oct 2022 01:18:27 -0700, Trolidan7
<Trol...@eternal-september.org> wrote:
On 10/23/22 11:50 PM, jillery wrote:Watch the cited videos. Erika points out the challenges of going from
Gutsick Gibbon is the Youtube handle of a biological anthropology PhD >> >> >> student named Eriks. Two of her recent videos discuss some of the
latest developments relating to the origins of human bipedalism:
<https://www.youtube.com/watch?v=kbQAgPSHbZE>
The above is a link to a 32-minute video where Erika discusses several
papers relating to Sahelanthropus tchadensis. This fossil is
remarkable in part because it's dated to about 7mya and was found in >> >> >> central-african Chad, and also because it may be the oldest bipedal >> >> >> hominin fossil found to date. However, there appears to be strong
disagreement whether the evidence supports bipedalism.
<https://www.youtube.com/watch?v=Nwkfkp360ps>
The above is a link to a 22-minute video where Erika discusses several
hypotheses about *why* our ancestors shifted to obligate bipedalism. >> >> >> She discusses several hypotheses, and presents compelling arguments >> >> >> for her preferred one.
I tend to think of it as none of the above.
Simply because it is not that easy to stand upright.
When an animal stands upright you need to solve a problem -
how do you keep from falling over forward and backward.
This might seem simple but it is not because with a four
footed animal the center of gravity forward and backward
is between the front legs and the back legs, and often
that is a greater distance than between the left legs and
the right legs.
quadruped to biped, the differences between upright posture and
bipedalism, and the plausibility of suspensory orthograde posture in
trees as a precursor to bipedalism on the ground.
Some animals that sort of walk on twos have not solved theThat's why humans like big butts, I can not lie.
problem - a kangaroo can hop but in general it can not
stably stand. Either way, in essence, the long hand enables
force to be supplied to the far front and far back to counter
falling forward or backward - the forefoot and big toe are
the front force appliers and the heel is the back force
applier. Then of course there are some animals that might
sort of walk on threes (I am thinking of the Jerboa) - but
humans have an extra problem because they have no tail to
possibly act as an extra walking limb, or at least a balance.
Bigger butt bones, bigger brain bones, initially.
Homo erectus had unusually thick dense femurs and unusually thick dense occiputs (rear skull bone), which counterbalanced the pace over orthogonal bipedal treks on the ground, substituting for the more typical long dense tail of other bipeds (T rex,
x arboreal bipedalism, as in European miocene - pliocene apes and similar to but distinct from faster extant gibbons.S chadensis was imo not a habitual nor obligate terrestrial orthograde biped, nor a part-time knucklewalking terrestrial quadruped, its foramen magnum reflected a more primitive arboreal orthograde bipedalism associated with suspensory slow brachiation@378 cm^3, S. tchadensis' braincase is similar to that of extant
Casually walking while chewing gum, chatting and carrying a squirming child is something only humans could ever do.
chimpanzees and approximately a third the size of modern human brains.
Chimps & gorillas became more quadrupedal (partly pronograde terrestrial knucklewalking) while Homo became more bipedal (fully orthograde habitual obligate terrestrial striding), these produced changes of position and orientation of the foramen magnum.
https://carta.anthropogeny.org/moca/topics/foramen-magnum-placement#:~:text=The%20foramen%20magnum%20position%20has,case%20for%20Ardipithecus%20and%20Sahelanthropus.
On Wed, 26 Oct 2022 03:17:08 -0700 (PDT), Daud Dedengiant short faced kangaroo, giant ground sloth, running jesus lizard). This primitive mechanical gyroscope was replaced by genetic software improvements enabling reduced body bone weight (esp. femur & occiput), faster & longer bipedal locomotion,
<daud....@gmail.com> wrote:
On Wednesday, October 26, 2022 at 4:10:49 AM UTC-4, 69jp...@gmail.com wrote:
On Tue, 25 Oct 2022 16:32:06 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Tuesday, October 25, 2022 at 6:59:05 PM UTC-4, 69jp...@gmail.com wrote:
On Tue, 25 Oct 2022 01:18:27 -0700, Trolidan7
<Trol...@eternal-september.org> wrote:
On 10/23/22 11:50 PM, jillery wrote:Watch the cited videos. Erika points out the challenges of going from >> >> quadruped to biped, the differences between upright posture and
Gutsick Gibbon is the Youtube handle of a biological anthropology PhD
student named Eriks. Two of her recent videos discuss some of the >> >> >> latest developments relating to the origins of human bipedalism:
<https://www.youtube.com/watch?v=kbQAgPSHbZE>
The above is a link to a 32-minute video where Erika discusses several
papers relating to Sahelanthropus tchadensis. This fossil is
remarkable in part because it's dated to about 7mya and was found in
central-african Chad, and also because it may be the oldest bipedal >> >> >> hominin fossil found to date. However, there appears to be strong >> >> >> disagreement whether the evidence supports bipedalism.
<https://www.youtube.com/watch?v=Nwkfkp360ps>
The above is a link to a 22-minute video where Erika discusses several
hypotheses about *why* our ancestors shifted to obligate bipedalism.
She discusses several hypotheses, and presents compelling arguments >> >> >> for her preferred one.
I tend to think of it as none of the above.
Simply because it is not that easy to stand upright.
When an animal stands upright you need to solve a problem -
how do you keep from falling over forward and backward.
This might seem simple but it is not because with a four
footed animal the center of gravity forward and backward
is between the front legs and the back legs, and often
that is a greater distance than between the left legs and
the right legs.
bipedalism, and the plausibility of suspensory orthograde posture in >> >> trees as a precursor to bipedalism on the ground.
Some animals that sort of walk on twos have not solved theThat's why humans like big butts, I can not lie.
problem - a kangaroo can hop but in general it can not
stably stand. Either way, in essence, the long hand enables
force to be supplied to the far front and far back to counter
falling forward or backward - the forefoot and big toe are
the front force appliers and the heel is the back force
applier. Then of course there are some animals that might
sort of walk on threes (I am thinking of the Jerboa) - but
humans have an extra problem because they have no tail to
possibly act as an extra walking limb, or at least a balance.
Bigger butt bones, bigger brain bones, initially.
Homo erectus had unusually thick dense femurs and unusually thick dense occiputs (rear skull bone), which counterbalanced the pace over orthogonal bipedal treks on the ground, substituting for the more typical long dense tail of other bipeds (T rex,
brachiation x arboreal bipedalism, as in European miocene - pliocene apes and similar to but distinct from faster extant gibbons.S chadensis was imo not a habitual nor obligate terrestrial orthograde biped, nor a part-time knucklewalking terrestrial quadruped, its foramen magnum reflected a more primitive arboreal orthograde bipedalism associated with suspensory slow@378 cm^3, S. tchadensis' braincase is similar to that of extant
Casually walking while chewing gum, chatting and carrying a squirming child is something only humans could ever do.
chimpanzees and approximately a third the size of modern human brains.
Chimps & gorillas became more quadrupedal (partly pronograde terrestrial knucklewalking) while Homo became more bipedal (fully orthograde habitual obligate terrestrial striding), these produced changes of position and orientation of the foramen magnum.
They mighthttps://carta.anthropogeny.org/moca/topics/foramen-magnum-placement#:~:text=The%20foramen%20magnum%20position%20has,case%20for%20Ardipithecus%20and%20Sahelanthropus.The authors of the paper Erika cited disagree with your opinion.
On Wednesday, October 26, 2022 at 7:56:43 PM UTC-4, 69jp...@gmail.com wrote: >> On Wed, 26 Oct 2022 03:17:08 -0700 (PDT), Daud Dedenrex, giant short faced kangaroo, giant ground sloth, running jesus lizard). This primitive mechanical gyroscope was replaced by genetic software improvements enabling reduced body bone weight (esp. femur & occiput), faster & longer bipedal locomotion,
<daud....@gmail.com> wrote:
On Wednesday, October 26, 2022 at 4:10:49 AM UTC-4, 69jp...@gmail.com wrote:
On Tue, 25 Oct 2022 16:32:06 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Tuesday, October 25, 2022 at 6:59:05 PM UTC-4, 69jp...@gmail.com wrote:
On Tue, 25 Oct 2022 01:18:27 -0700, Trolidan7
<Trol...@eternal-september.org> wrote:
On 10/23/22 11:50 PM, jillery wrote:Watch the cited videos. Erika points out the challenges of going from >> >> >> quadruped to biped, the differences between upright posture and
Gutsick Gibbon is the Youtube handle of a biological anthropology PhD
student named Eriks. Two of her recent videos discuss some of the >> >> >> >> latest developments relating to the origins of human bipedalism: >> >> >> >>
<https://www.youtube.com/watch?v=kbQAgPSHbZE>
The above is a link to a 32-minute video where Erika discusses several
papers relating to Sahelanthropus tchadensis. This fossil is
remarkable in part because it's dated to about 7mya and was found in
central-african Chad, and also because it may be the oldest bipedal
hominin fossil found to date. However, there appears to be strong >> >> >> >> disagreement whether the evidence supports bipedalism.
<https://www.youtube.com/watch?v=Nwkfkp360ps>
The above is a link to a 22-minute video where Erika discusses several
hypotheses about *why* our ancestors shifted to obligate bipedalism.
She discusses several hypotheses, and presents compelling arguments
for her preferred one.
I tend to think of it as none of the above.
Simply because it is not that easy to stand upright.
When an animal stands upright you need to solve a problem -
how do you keep from falling over forward and backward.
This might seem simple but it is not because with a four
footed animal the center of gravity forward and backward
is between the front legs and the back legs, and often
that is a greater distance than between the left legs and
the right legs.
bipedalism, and the plausibility of suspensory orthograde posture in >> >> >> trees as a precursor to bipedalism on the ground.
Some animals that sort of walk on twos have not solved theThat's why humans like big butts, I can not lie.
problem - a kangaroo can hop but in general it can not
stably stand. Either way, in essence, the long hand enables
force to be supplied to the far front and far back to counter
falling forward or backward - the forefoot and big toe are
the front force appliers and the heel is the back force
applier. Then of course there are some animals that might
sort of walk on threes (I am thinking of the Jerboa) - but
humans have an extra problem because they have no tail to
possibly act as an extra walking limb, or at least a balance.
Bigger butt bones, bigger brain bones, initially.
Homo erectus had unusually thick dense femurs and unusually thick dense occiputs (rear skull bone), which counterbalanced the pace over orthogonal bipedal treks on the ground, substituting for the more typical long dense tail of other bipeds (T
brachiation x arboreal bipedalism, as in European miocene - pliocene apes and similar to but distinct from faster extant gibbons.@378 cm^3, S. tchadensis' braincase is similar to that of extant
Casually walking while chewing gum, chatting and carrying a squirming child is something only humans could ever do.
chimpanzees and approximately a third the size of modern human brains. >> >S chadensis was imo not a habitual nor obligate terrestrial orthograde biped, nor a part-time knucklewalking terrestrial quadruped, its foramen magnum reflected a more primitive arboreal orthograde bipedalism associated with suspensory slow
magnum.
Chimps & gorillas became more quadrupedal (partly pronograde terrestrial knucklewalking) while Homo became more bipedal (fully orthograde habitual obligate terrestrial striding), these produced changes of position and orientation of the foramen
They might be right.The authors of the paper Erika cited disagree with your opinion.
https://carta.anthropogeny.org/moca/topics/foramen-magnum-placement#:~:text=The%20foramen%20magnum%20position%20has,case%20for%20Ardipithecus%20and%20Sahelanthropus.
On Thu, 27 Oct 2022 02:17:42 -0700 (PDT), Daud Dedenrex, giant short faced kangaroo, giant ground sloth, running jesus lizard). This primitive mechanical gyroscope was replaced by genetic software improvements enabling reduced body bone weight (esp. femur & occiput), faster & longer bipedal locomotion,
<daud....@gmail.com> wrote:
On Wednesday, October 26, 2022 at 7:56:43 PM UTC-4, 69jp...@gmail.com wrote:
On Wed, 26 Oct 2022 03:17:08 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Wednesday, October 26, 2022 at 4:10:49 AM UTC-4, 69jp...@gmail.com wrote:
On Tue, 25 Oct 2022 16:32:06 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Tuesday, October 25, 2022 at 6:59:05 PM UTC-4, 69jp...@gmail.com wrote:
On Tue, 25 Oct 2022 01:18:27 -0700, Trolidan7
<Trol...@eternal-september.org> wrote:
On 10/23/22 11:50 PM, jillery wrote:Watch the cited videos. Erika points out the challenges of going from
Gutsick Gibbon is the Youtube handle of a biological anthropology PhD
student named Eriks. Two of her recent videos discuss some of the
latest developments relating to the origins of human bipedalism: >> >> >> >>
<https://www.youtube.com/watch?v=kbQAgPSHbZE>
The above is a link to a 32-minute video where Erika discusses several
papers relating to Sahelanthropus tchadensis. This fossil is
remarkable in part because it's dated to about 7mya and was found in
central-african Chad, and also because it may be the oldest bipedal
hominin fossil found to date. However, there appears to be strong
disagreement whether the evidence supports bipedalism.
<https://www.youtube.com/watch?v=Nwkfkp360ps>
The above is a link to a 22-minute video where Erika discusses several
hypotheses about *why* our ancestors shifted to obligate bipedalism.
She discusses several hypotheses, and presents compelling arguments
for her preferred one.
I tend to think of it as none of the above.
Simply because it is not that easy to stand upright.
When an animal stands upright you need to solve a problem -
how do you keep from falling over forward and backward.
This might seem simple but it is not because with a four
footed animal the center of gravity forward and backward
is between the front legs and the back legs, and often
that is a greater distance than between the left legs and
the right legs.
quadruped to biped, the differences between upright posture and
bipedalism, and the plausibility of suspensory orthograde posture in
trees as a precursor to bipedalism on the ground.
Some animals that sort of walk on twos have not solved theThat's why humans like big butts, I can not lie.
problem - a kangaroo can hop but in general it can not
stably stand. Either way, in essence, the long hand enables
force to be supplied to the far front and far back to counter
falling forward or backward - the forefoot and big toe are
the front force appliers and the heel is the back force
applier. Then of course there are some animals that might
sort of walk on threes (I am thinking of the Jerboa) - but
humans have an extra problem because they have no tail to
possibly act as an extra walking limb, or at least a balance.
Bigger butt bones, bigger brain bones, initially.
Homo erectus had unusually thick dense femurs and unusually thick dense occiputs (rear skull bone), which counterbalanced the pace over orthogonal bipedal treks on the ground, substituting for the more typical long dense tail of other bipeds (T
brachiation x arboreal bipedalism, as in European miocene - pliocene apes and similar to but distinct from faster extant gibbons.@378 cm^3, S. tchadensis' braincase is similar to that of extant
Casually walking while chewing gum, chatting and carrying a squirming child is something only humans could ever do.
chimpanzees and approximately a third the size of modern human brains. >> >S chadensis was imo not a habitual nor obligate terrestrial orthograde biped, nor a part-time knucklewalking terrestrial quadruped, its foramen magnum reflected a more primitive arboreal orthograde bipedalism associated with suspensory slow
magnum.
Chimps & gorillas became more quadrupedal (partly pronograde terrestrial knucklewalking) while Homo became more bipedal (fully orthograde habitual obligate terrestrial striding), these produced changes of position and orientation of the foramen
If only there were some way to judge between contrasting opinions...They might be right.The authors of the paper Erika cited disagree with your opinion.
https://carta.anthropogeny.org/moca/topics/foramen-magnum-placement#:~:text=The%20foramen%20magnum%20position%20has,case%20for%20Ardipithecus%20and%20Sahelanthropus.
Gutsick Gibbon is the Youtube handle of a biological anthropology PhD
student named Eriks. Two of her recent videos discuss some of the
latest developments relating to the origins of human bipedalism:
<https://www.youtube.com/watch?v=kbQAgPSHbZE>
The above is a link to a 32-minute video where Erika discusses several
papers relating to Sahelanthropus tchadensis.
This fossil is remarkable in part because it's dated to about 7mya and was found in
central-african Chad, and also because it may be the oldest bipedal
hominin fossil found to date. However, there appears to be strong disagreement whether the evidence supports bipedalism.
<https://www.youtube.com/watch?v=Nwkfkp360ps>
The above is a link to a 22-minute video where Erika discusses several hypotheses about *why* our ancestors shifted to obligate bipedalism.
She discusses several hypotheses, and presents compelling arguments
for her preferred one.
How about that! You, who seldom post here, actually did an on-topic OP.
This puts you ahead of John Harshman: in the almost dozen years
since I returned here, I don't recall him ever doing an on-topic OP to sci.bio.paleontology.
This despite the fact that he has probably done a few thousand posts
here in that time.
I do have a few recommendations. The optimal place to post information about >homini is sci.anthropology.paleo. Not only are they the "specialty" of that ng,
it is more active, with more regulars than s.b.p. Best of all perhaps, Pandora >takes a very active part there, going into depth with one person after another.
Pandora occasionally posts to s.b.p. too, but the majority of her posts here are OP's.
They are almost invariably excellent and thought-provoking, but she seldom >comments on the thoughts she has provoked, even when they are on-topic
in every sense of the word.
On Monday, October 24, 2022 at 2:50:22 AM UTC-4, 69jp...@gmail.com wrote:
Gutsick Gibbon is the Youtube handle of a biological anthropology PhD
student named Erika. Two of her recent videos discuss some of the
latest developments relating to the origins of human bipedalism:
<https://www.youtube.com/watch?v=kbQAgPSHbZE>
The above is a link to a 32-minute video where Erika discusses several
papers relating to Sahelanthropus tchadensis.
I don't have enough time this evening to watch either this video or
the one you mention below. This being a science ng, it is very
appropriate to give the titles of these papers. Those of us who
are interested in research papers shouldn't have to sit through a video
to find out what they are.
This fossil is remarkable in part because it's dated to about 7mya and was found in
central-african Chad, and also because it may be the oldest bipedal
hominin fossil found to date. However, there appears to be strong
disagreement whether the evidence supports bipedalism.
<https://www.youtube.com/watch?v=Nwkfkp360ps>
The above is a link to a 22-minute video where Erika discusses several
hypotheses about *why* our ancestors shifted to obligate bipedalism.
She discusses several hypotheses, and presents compelling arguments
for her preferred one.
In science, hypotheses on such an open ended theme are seldom
compelling. Before you decide to post this to s.a.p., I strongly recommend >that you state this preferred hypothesis; some people there may already
have heard of it (especially Pandora, who comes across as a professional
well past the age of earning the Ph.D.) and have formulated ideas about it.
On Thursday, October 27, 2022 at 5:53:29 AM UTC-4, 69jp...@gmail.com wrote:rex, giant short faced kangaroo, giant ground sloth, running jesus lizard). This primitive mechanical gyroscope was replaced by genetic software improvements enabling reduced body bone weight (esp. femur & occiput), faster & longer bipedal locomotion,
On Thu, 27 Oct 2022 02:17:42 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Wednesday, October 26, 2022 at 7:56:43 PM UTC-4, 69jp...@gmail.com wrote:
On Wed, 26 Oct 2022 03:17:08 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Wednesday, October 26, 2022 at 4:10:49 AM UTC-4, 69jp...@gmail.com wrote:
On Tue, 25 Oct 2022 16:32:06 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Tuesday, October 25, 2022 at 6:59:05 PM UTC-4, 69jp...@gmail.com wrote:
On Tue, 25 Oct 2022 01:18:27 -0700, Trolidan7
<Trol...@eternal-september.org> wrote:
On 10/23/22 11:50 PM, jillery wrote:Watch the cited videos. Erika points out the challenges of going from
Gutsick Gibbon is the Youtube handle of a biological anthropology PhD
student named Erika. Two of her recent videos discuss some of the
latest developments relating to the origins of human bipedalism:
<https://www.youtube.com/watch?v=kbQAgPSHbZE>
The above is a link to a 32-minute video where Erika discusses several
papers relating to Sahelanthropus tchadensis. This fossil is
remarkable in part because it's dated to about 7mya and was found in
central-african Chad, and also because it may be the oldest bipedal
hominin fossil found to date. However, there appears to be strong
disagreement whether the evidence supports bipedalism.
<https://www.youtube.com/watch?v=Nwkfkp360ps>
The above is a link to a 22-minute video where Erika discusses several
hypotheses about *why* our ancestors shifted to obligate bipedalism.
She discusses several hypotheses, and presents compelling arguments
for her preferred one.
I tend to think of it as none of the above.
Simply because it is not that easy to stand upright.
When an animal stands upright you need to solve a problem -
how do you keep from falling over forward and backward.
This might seem simple but it is not because with a four
footed animal the center of gravity forward and backward
is between the front legs and the back legs, and often
that is a greater distance than between the left legs and
the right legs.
quadruped to biped, the differences between upright posture and
bipedalism, and the plausibility of suspensory orthograde posture in
trees as a precursor to bipedalism on the ground.
Some animals that sort of walk on twos have not solved theThat's why humans like big butts, I can not lie.
problem - a kangaroo can hop but in general it can not
stably stand. Either way, in essence, the long hand enables
force to be supplied to the far front and far back to counter
falling forward or backward - the forefoot and big toe are
the front force appliers and the heel is the back force
applier. Then of course there are some animals that might
sort of walk on threes (I am thinking of the Jerboa) - but
humans have an extra problem because they have no tail to
possibly act as an extra walking limb, or at least a balance.
Bigger butt bones, bigger brain bones, initially.
Homo erectus had unusually thick dense femurs and unusually thick dense occiputs (rear skull bone), which counterbalanced the pace over orthogonal bipedal treks on the ground, substituting for the more typical long dense tail of other bipeds (T
brachiation x arboreal bipedalism, as in European miocene - pliocene apes and similar to but distinct from faster extant gibbons.S chadensis was imo not a habitual nor obligate terrestrial orthograde biped, nor a part-time knucklewalking terrestrial quadruped, its foramen magnum reflected a more primitive arboreal orthograde bipedalism associated with suspensory slow@378 cm^3, S. tchadensis' braincase is similar to that of extant
Casually walking while chewing gum, chatting and carrying a squirming child is something only humans could ever do.
chimpanzees and approximately a third the size of modern human brains.
magnum.
Chimps & gorillas became more quadrupedal (partly pronograde terrestrial knucklewalking) while Homo became more bipedal (fully orthograde habitual obligate terrestrial striding), these produced changes of position and orientation of the foramen
If only there were some way to judge between contrasting opinions...They might be right.The authors of the paper Erika cited disagree with your opinion.
https://carta.anthropogeny.org/moca/topics/foramen-magnum-placement#:~:text=The%20foramen%20magnum%20position%20has,case%20for%20Ardipithecus%20and%20Sahelanthropus.
Parsimony is good.
Please direct me to the author(s) who disagree with what I wrote earlier. I don't know where to start, which vid, which paper... I'll examine inconsistencies (their or mine).
On 10/23/22 11:50 PM, jillery wrote:
Gutsick Gibbon is the Youtube handle of a biological anthropology PhD student named Eriks. Two of her recent videos discuss some of the
latest developments relating to the origins of human bipedalism:
<https://www.youtube.com/watch?v=kbQAgPSHbZE>
The above is a link to a 32-minute video where Erika discusses several papers relating to Sahelanthropus tchadensis. This fossil is
remarkable in part because it's dated to about 7mya and was found in central-african Chad, and also because it may be the oldest bipedal
hominin fossil found to date. However, there appears to be strong disagreement whether the evidence supports bipedalism.
<https://www.youtube.com/watch?v=Nwkfkp360ps>
The above is a link to a 22-minute video where Erika discusses several hypotheses about *why* our ancestors shifted to obligate bipedalism.
She discusses several hypotheses, and presents compelling arguments
for her preferred one.
I tend to think of it as none of the above.
Simply because it is not that easy to stand upright.
When an animal stands upright you need to solve a problem -
how do you keep from falling over forward and backward.
This might seem simple but it is not because with a four
footed animal the center of gravity forward and backward
is between the front legs and the back legs, and often
that is a greater distance than between the left legs and
the right legs.
Some animals that sort of walk on twos have not solved the
problem - a kangaroo can hop but in general it can not
stably stand.
Either way, in essence, the long hand enables
force to be supplied to the far front and far back to counter
falling forward or backward - the forefoot and big toe are
the front force appliers and the heel is the back force
applier. Then of course there are some animals that might
sort of walk on threes (I am thinking of the Jerboa) - but
humans have an extra problem because they have no tail to
possibly act as an extra walking limb, or at least a balance.
On Thu, 27 Oct 2022 16:44:19 -0700 (PDT), Daud DedenT rex, giant short faced kangaroo, giant ground sloth, running jesus lizard). This primitive mechanical gyroscope was replaced by genetic software improvements enabling reduced body bone weight (esp. femur & occiput), faster & longer bipedal locomotion,
<daud....@gmail.com> wrote:
On Thursday, October 27, 2022 at 5:53:29 AM UTC-4, 69jp...@gmail.com wrote: >> On Thu, 27 Oct 2022 02:17:42 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Wednesday, October 26, 2022 at 7:56:43 PM UTC-4, 69jp...@gmail.com wrote:
On Wed, 26 Oct 2022 03:17:08 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Wednesday, October 26, 2022 at 4:10:49 AM UTC-4, 69jp...@gmail.com wrote:
On Tue, 25 Oct 2022 16:32:06 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Tuesday, October 25, 2022 at 6:59:05 PM UTC-4, 69jp...@gmail.com wrote:
On Tue, 25 Oct 2022 01:18:27 -0700, Trolidan7
<Trol...@eternal-september.org> wrote:
On 10/23/22 11:50 PM, jillery wrote:Watch the cited videos. Erika points out the challenges of going from
Gutsick Gibbon is the Youtube handle of a biological anthropology PhD
student named Erika. Two of her recent videos discuss some of the
latest developments relating to the origins of human bipedalism:
<https://www.youtube.com/watch?v=kbQAgPSHbZE>
The above is a link to a 32-minute video where Erika discusses several
papers relating to Sahelanthropus tchadensis. This fossil is >> >> >> >> >> remarkable in part because it's dated to about 7mya and was found in
central-african Chad, and also because it may be the oldest bipedal
hominin fossil found to date. However, there appears to be strong
disagreement whether the evidence supports bipedalism.
<https://www.youtube.com/watch?v=Nwkfkp360ps>
The above is a link to a 22-minute video where Erika discusses several
hypotheses about *why* our ancestors shifted to obligate bipedalism.
She discusses several hypotheses, and presents compelling arguments
for her preferred one.
I tend to think of it as none of the above.
Simply because it is not that easy to stand upright.
When an animal stands upright you need to solve a problem -
how do you keep from falling over forward and backward.
This might seem simple but it is not because with a four
footed animal the center of gravity forward and backward
is between the front legs and the back legs, and often
that is a greater distance than between the left legs and
the right legs.
quadruped to biped, the differences between upright posture and >> >> >> >> bipedalism, and the plausibility of suspensory orthograde posture in
trees as a precursor to bipedalism on the ground.
Some animals that sort of walk on twos have not solved the
problem - a kangaroo can hop but in general it can not
stably stand. Either way, in essence, the long hand enables
force to be supplied to the far front and far back to counter >> >> >> >> >falling forward or backward - the forefoot and big toe are
the front force appliers and the heel is the back force
applier. Then of course there are some animals that might
sort of walk on threes (I am thinking of the Jerboa) - but
humans have an extra problem because they have no tail to
possibly act as an extra walking limb, or at least a balance. >> >> >> >> That's why humans like big butts, I can not lie.
Bigger butt bones, bigger brain bones, initially.
Homo erectus had unusually thick dense femurs and unusually thick dense occiputs (rear skull bone), which counterbalanced the pace over orthogonal bipedal treks on the ground, substituting for the more typical long dense tail of other bipeds (
brachiation x arboreal bipedalism, as in European miocene - pliocene apes and similar to but distinct from faster extant gibbons.S chadensis was imo not a habitual nor obligate terrestrial orthograde biped, nor a part-time knucklewalking terrestrial quadruped, its foramen magnum reflected a more primitive arboreal orthograde bipedalism associated with suspensory slow@378 cm^3, S. tchadensis' braincase is similar to that of extant
Casually walking while chewing gum, chatting and carrying a squirming child is something only humans could ever do.
chimpanzees and approximately a third the size of modern human brains.
magnum.
Chimps & gorillas became more quadrupedal (partly pronograde terrestrial knucklewalking) while Homo became more bipedal (fully orthograde habitual obligate terrestrial striding), these produced changes of position and orientation of the foramen
Ok, I'd watched half of the 2nd video. I'll watch both tomorrow. I'll certainly learn something, I always do. For now, I stand behind every word I wrote earlier about Homo & Sahelanthropus.If only there were some way to judge between contrasting opinions...They might be right.The authors of the paper Erika cited disagree with your opinion.
https://carta.anthropogeny.org/moca/topics/foramen-magnum-placement#:~:text=The%20foramen%20magnum%20position%20has,case%20for%20Ardipithecus%20and%20Sahelanthropus.
Parsimony is good.Once again, watch the cited video. Erika identifies the paper in the
Please direct me to the author(s) who disagree with what I wrote earlier. I don't know where to start, which vid, which paper... I'll examine inconsistencies (their or mine).
first few minutes of the first vdeo. But if you watch/listen to all
of both, you might actually learn something.
On Friday, October 28, 2022 at 12:13:33 AM UTC-4, Daud Deden wrote:bipeds (T rex, giant short faced kangaroo, giant ground sloth, running jesus lizard). This primitive mechanical gyroscope was replaced by genetic software improvements enabling reduced body bone weight (esp. femur & occiput), faster & longer bipedal
On Thursday, October 27, 2022 at 10:56:53 PM UTC-4, 69jp...@gmail.com wrote:
On Thu, 27 Oct 2022 16:44:19 -0700 (PDT), Daud Deden <daud....@gmail.com> wrote:
On Thursday, October 27, 2022 at 5:53:29 AM UTC-4, 69jp...@gmail.com wrote:
On Thu, 27 Oct 2022 02:17:42 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Wednesday, October 26, 2022 at 7:56:43 PM UTC-4, 69jp...@gmail.com wrote:
On Wed, 26 Oct 2022 03:17:08 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Wednesday, October 26, 2022 at 4:10:49 AM UTC-4, 69jp...@gmail.com wrote:
On Tue, 25 Oct 2022 16:32:06 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Tuesday, October 25, 2022 at 6:59:05 PM UTC-4, 69jp...@gmail.com wrote:
On Tue, 25 Oct 2022 01:18:27 -0700, Trolidan7
<Trol...@eternal-september.org> wrote:
On 10/23/22 11:50 PM, jillery wrote:Watch the cited videos. Erika points out the challenges of going from
Gutsick Gibbon is the Youtube handle of a biological anthropology PhD
student named Erika. Two of her recent videos discuss some of the
latest developments relating to the origins of human bipedalism:
<https://www.youtube.com/watch?v=kbQAgPSHbZE>
The above is a link to a 32-minute video where Erika discusses several
papers relating to Sahelanthropus tchadensis. This fossil is
remarkable in part because it's dated to about 7mya and was found in
central-african Chad, and also because it may be the oldest bipedal
hominin fossil found to date. However, there appears to be strong
disagreement whether the evidence supports bipedalism.
<https://www.youtube.com/watch?v=Nwkfkp360ps>
The above is a link to a 22-minute video where Erika discusses several
hypotheses about *why* our ancestors shifted to obligate bipedalism.
She discusses several hypotheses, and presents compelling arguments
for her preferred one.
I tend to think of it as none of the above.
Simply because it is not that easy to stand upright.
When an animal stands upright you need to solve a problem - >> >> >> >> >how do you keep from falling over forward and backward.
This might seem simple but it is not because with a four
footed animal the center of gravity forward and backward
is between the front legs and the back legs, and often
that is a greater distance than between the left legs and >> >> >> >> >the right legs.
quadruped to biped, the differences between upright posture and
bipedalism, and the plausibility of suspensory orthograde posture in
trees as a precursor to bipedalism on the ground.
Some animals that sort of walk on twos have not solved the >> >> >> >> >problem - a kangaroo can hop but in general it can notThat's why humans like big butts, I can not lie.
stably stand. Either way, in essence, the long hand enables >> >> >> >> >force to be supplied to the far front and far back to counter
falling forward or backward - the forefoot and big toe are >> >> >> >> >the front force appliers and the heel is the back force
applier. Then of course there are some animals that might >> >> >> >> >sort of walk on threes (I am thinking of the Jerboa) - but >> >> >> >> >humans have an extra problem because they have no tail to >> >> >> >> >possibly act as an extra walking limb, or at least a balance.
Bigger butt bones, bigger brain bones, initially.
Homo erectus had unusually thick dense femurs and unusually thick dense occiputs (rear skull bone), which counterbalanced the pace over orthogonal bipedal treks on the ground, substituting for the more typical long dense tail of other
brachiation x arboreal bipedalism, as in European miocene - pliocene apes and similar to but distinct from faster extant gibbons.S chadensis was imo not a habitual nor obligate terrestrial orthograde biped, nor a part-time knucklewalking terrestrial quadruped, its foramen magnum reflected a more primitive arboreal orthograde bipedalism associated with suspensory slow@378 cm^3, S. tchadensis' braincase is similar to that of extant
Casually walking while chewing gum, chatting and carrying a squirming child is something only humans could ever do.
chimpanzees and approximately a third the size of modern human brains.
foramen magnum.
Chimps & gorillas became more quadrupedal (partly pronograde terrestrial knucklewalking) while Homo became more bipedal (fully orthograde habitual obligate terrestrial striding), these produced changes of position and orientation of the
I am so far sorely disappointed. At around 8:23, Erika intelligently but ignorantly describes the position of the foramen magnum and its significance. To her, bipedalism is terrestrial bipedalism. That is the central flaw in the study of hominoid,If only there were some way to judge between contrasting opinions...The authors of the paper Erika cited disagree with your opinion. >> >They might be right.
https://carta.anthropogeny.org/moca/topics/foramen-magnum-placement#:~:text=The%20foramen%20magnum%20position%20has,case%20for%20Ardipithecus%20and%20Sahelanthropus.
After a sneak peek, I see the paper, Postcranial ..., about the femur. I've skimmed it, no change in my thinking. But I'm flexible.Ok, I'd watched half of the 2nd video. I'll watch both tomorrow. I'll certainly learn something, I always do. For now, I stand behind every word I wrote earlier about Homo & Sahelanthropus.Parsimony is good.Once again, watch the cited video. Erika identifies the paper in the first few minutes of the first vdeo. But if you watch/listen to all
Please direct me to the author(s) who disagree with what I wrote earlier. I don't know where to start, which vid, which paper... I'll examine inconsistencies (their or mine).
of both, you might actually learn something.
On Thursday, October 27, 2022 at 10:56:53 PM UTC-4, 69jp...@gmail.com wrote:bipeds (T rex, giant short faced kangaroo, giant ground sloth, running jesus lizard). This primitive mechanical gyroscope was replaced by genetic software improvements enabling reduced body bone weight (esp. femur & occiput), faster & longer bipedal
On Thu, 27 Oct 2022 16:44:19 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Thursday, October 27, 2022 at 5:53:29 AM UTC-4, 69jp...@gmail.com wrote:
On Thu, 27 Oct 2022 02:17:42 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Wednesday, October 26, 2022 at 7:56:43 PM UTC-4, 69jp...@gmail.com wrote:
On Wed, 26 Oct 2022 03:17:08 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Wednesday, October 26, 2022 at 4:10:49 AM UTC-4, 69jp...@gmail.com wrote:
On Tue, 25 Oct 2022 16:32:06 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Tuesday, October 25, 2022 at 6:59:05 PM UTC-4, 69jp...@gmail.com wrote:
On Tue, 25 Oct 2022 01:18:27 -0700, Trolidan7
<Trol...@eternal-september.org> wrote:
On 10/23/22 11:50 PM, jillery wrote:Watch the cited videos. Erika points out the challenges of going from
Gutsick Gibbon is the Youtube handle of a biological anthropology PhD
student named Erika. Two of her recent videos discuss some of the
latest developments relating to the origins of human bipedalism:
<https://www.youtube.com/watch?v=kbQAgPSHbZE>
The above is a link to a 32-minute video where Erika discusses several
papers relating to Sahelanthropus tchadensis. This fossil is
remarkable in part because it's dated to about 7mya and was found in
central-african Chad, and also because it may be the oldest bipedal
hominin fossil found to date. However, there appears to be strong
disagreement whether the evidence supports bipedalism.
<https://www.youtube.com/watch?v=Nwkfkp360ps>
The above is a link to a 22-minute video where Erika discusses several
hypotheses about *why* our ancestors shifted to obligate bipedalism.
She discusses several hypotheses, and presents compelling arguments
for her preferred one.
I tend to think of it as none of the above.
Simply because it is not that easy to stand upright.
When an animal stands upright you need to solve a problem - >> >> >> >> >how do you keep from falling over forward and backward.
This might seem simple but it is not because with a four
footed animal the center of gravity forward and backward
is between the front legs and the back legs, and often
that is a greater distance than between the left legs and
the right legs.
quadruped to biped, the differences between upright posture and
bipedalism, and the plausibility of suspensory orthograde posture in
trees as a precursor to bipedalism on the ground.
Some animals that sort of walk on twos have not solved the
problem - a kangaroo can hop but in general it can not
stably stand. Either way, in essence, the long hand enables >> >> >> >> >force to be supplied to the far front and far back to counter >> >> >> >> >falling forward or backward - the forefoot and big toe are
the front force appliers and the heel is the back force
applier. Then of course there are some animals that might
sort of walk on threes (I am thinking of the Jerboa) - but
humans have an extra problem because they have no tail to
possibly act as an extra walking limb, or at least a balance. >> >> >> >> That's why humans like big butts, I can not lie.
Bigger butt bones, bigger brain bones, initially.
Homo erectus had unusually thick dense femurs and unusually thick dense occiputs (rear skull bone), which counterbalanced the pace over orthogonal bipedal treks on the ground, substituting for the more typical long dense tail of other
brachiation x arboreal bipedalism, as in European miocene - pliocene apes and similar to but distinct from faster extant gibbons.S chadensis was imo not a habitual nor obligate terrestrial orthograde biped, nor a part-time knucklewalking terrestrial quadruped, its foramen magnum reflected a more primitive arboreal orthograde bipedalism associated with suspensory slow@378 cm^3, S. tchadensis' braincase is similar to that of extant >> >> >> chimpanzees and approximately a third the size of modern human brains.
Casually walking while chewing gum, chatting and carrying a squirming child is something only humans could ever do.
foramen magnum.
Chimps & gorillas became more quadrupedal (partly pronograde terrestrial knucklewalking) while Homo became more bipedal (fully orthograde habitual obligate terrestrial striding), these produced changes of position and orientation of the
After a sneak peek, I see the paper, Postcranial ..., about the femur. I've skimmed it, no change in my thinking. But I'm flexible.If only there were some way to judge between contrasting opinions...They might be right.The authors of the paper Erika cited disagree with your opinion.
https://carta.anthropogeny.org/moca/topics/foramen-magnum-placement#:~:text=The%20foramen%20magnum%20position%20has,case%20for%20Ardipithecus%20and%20Sahelanthropus.
Ok, I'd watched half of the 2nd video. I'll watch both tomorrow. I'll certainly learn something, I always do. For now, I stand behind every word I wrote earlier about Homo & Sahelanthropus.Parsimony is good.Once again, watch the cited video. Erika identifies the paper in the
Please direct me to the author(s) who disagree with what I wrote earlier. I don't know where to start, which vid, which paper... I'll examine inconsistencies (their or mine).
first few minutes of the first vdeo. But if you watch/listen to all
of both, you might actually learn something.
On Friday, October 28, 2022 at 12:20:59 AM UTC-4, Daud Deden wrote:bipeds (T rex, giant short faced kangaroo, giant ground sloth, running jesus lizard). This primitive mechanical gyroscope was replaced by genetic software improvements enabling reduced body bone weight (esp. femur & occiput), faster & longer bipedal
On Friday, October 28, 2022 at 12:13:33 AM UTC-4, Daud Deden wrote:
On Thursday, October 27, 2022 at 10:56:53 PM UTC-4, 69jp...@gmail.com wrote:
On Thu, 27 Oct 2022 16:44:19 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Thursday, October 27, 2022 at 5:53:29 AM UTC-4, 69jp...@gmail.com wrote:
On Thu, 27 Oct 2022 02:17:42 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Wednesday, October 26, 2022 at 7:56:43 PM UTC-4, 69jp...@gmail.com wrote:
On Wed, 26 Oct 2022 03:17:08 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Wednesday, October 26, 2022 at 4:10:49 AM UTC-4, 69jp...@gmail.com wrote:
On Tue, 25 Oct 2022 16:32:06 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Tuesday, October 25, 2022 at 6:59:05 PM UTC-4, 69jp...@gmail.com wrote:
On Tue, 25 Oct 2022 01:18:27 -0700, Trolidan7
<Trol...@eternal-september.org> wrote:
On 10/23/22 11:50 PM, jillery wrote:Watch the cited videos. Erika points out the challenges of going from
Gutsick Gibbon is the Youtube handle of a biological anthropology PhD
student named Erika. Two of her recent videos discuss some of the
latest developments relating to the origins of human bipedalism:
<https://www.youtube.com/watch?v=kbQAgPSHbZE>
The above is a link to a 32-minute video where Erika discusses several
papers relating to Sahelanthropus tchadensis. This fossil is
remarkable in part because it's dated to about 7mya and was found in
central-african Chad, and also because it may be the oldest bipedal
hominin fossil found to date. However, there appears to be strong
disagreement whether the evidence supports bipedalism. >> > > >> >> >> >> >>
<https://www.youtube.com/watch?v=Nwkfkp360ps>
The above is a link to a 22-minute video where Erika discusses several
hypotheses about *why* our ancestors shifted to obligate bipedalism.
She discusses several hypotheses, and presents compelling arguments
for her preferred one.
I tend to think of it as none of the above.
Simply because it is not that easy to stand upright.
When an animal stands upright you need to solve a problem -
how do you keep from falling over forward and backward.
This might seem simple but it is not because with a four >> > > >> >> >> >> >footed animal the center of gravity forward and backward >> > > >> >> >> >> >is between the front legs and the back legs, and often
that is a greater distance than between the left legs and >> > > >> >> >> >> >the right legs.
quadruped to biped, the differences between upright posture and
bipedalism, and the plausibility of suspensory orthograde posture in
trees as a precursor to bipedalism on the ground.
Some animals that sort of walk on twos have not solved the >> > > >> >> >> >> >problem - a kangaroo can hop but in general it can notThat's why humans like big butts, I can not lie.
stably stand. Either way, in essence, the long hand enables
force to be supplied to the far front and far back to counter
falling forward or backward - the forefoot and big toe are >> > > >> >> >> >> >the front force appliers and the heel is the back force
applier. Then of course there are some animals that might >> > > >> >> >> >> >sort of walk on threes (I am thinking of the Jerboa) - but >> > > >> >> >> >> >humans have an extra problem because they have no tail to >> > > >> >> >> >> >possibly act as an extra walking limb, or at least a balance.
Bigger butt bones, bigger brain bones, initially.
Homo erectus had unusually thick dense femurs and unusually thick dense occiputs (rear skull bone), which counterbalanced the pace over orthogonal bipedal treks on the ground, substituting for the more typical long dense tail of other
brachiation x arboreal bipedalism, as in European miocene - pliocene apes and similar to but distinct from faster extant gibbons.S chadensis was imo not a habitual nor obligate terrestrial orthograde biped, nor a part-time knucklewalking terrestrial quadruped, its foramen magnum reflected a more primitive arboreal orthograde bipedalism associated with suspensory slow@378 cm^3, S. tchadensis' braincase is similar to that of extant
Casually walking while chewing gum, chatting and carrying a squirming child is something only humans could ever do.
chimpanzees and approximately a third the size of modern human brains.
foramen magnum.
Chimps & gorillas became more quadrupedal (partly pronograde terrestrial knucklewalking) while Homo became more bipedal (fully orthograde habitual obligate terrestrial striding), these produced changes of position and orientation of the
hominin & Homo evolution, one which I have already specifically addressed earlier. She and the various authors seem to be unable to comprehend the significance of arboreal habitual bipedalism. The authors do not disagree with my opinion, they are notI am so far sorely disappointed. At around 8:23, Erika intelligently but ignorantly describes the position of the foramen magnum and its significance. To her, bipedalism is terrestrial bipedalism. That is the central flaw in the study of hominoid,After a sneak peek, I see the paper, Postcranial ..., about the femur. I've skimmed it, no change in my thinking. But I'm flexible.Ok, I'd watched half of the 2nd video. I'll watch both tomorrow. I'll certainly learn something, I always do. For now, I stand behind every word I wrote earlier about Homo & Sahelanthropus.Once again, watch the cited video. Erika identifies the paper in theParsimony is good.If only there were some way to judge between contrasting opinions... >> > > >The authors of the paper Erika cited disagree with your opinion. >> > > >> >They might be right.
https://carta.anthropogeny.org/moca/topics/foramen-magnum-placement#:~:text=The%20foramen%20magnum%20position%20has,case%20for%20Ardipithecus%20and%20Sahelanthropus.
Please direct me to the author(s) who disagree with what I wrote earlier. I don't know where to start, which vid, which paper... I'll examine inconsistencies (their or mine).
first few minutes of the first vdeo. But if you watch/listen to all
of both, you might actually learn something.
On Thu, 27 Oct 2022 21:53:46 -0700 (PDT), Daud Dedenbipeds (T rex, giant short faced kangaroo, giant ground sloth, running jesus lizard). This primitive mechanical gyroscope was replaced by genetic software improvements enabling reduced body bone weight (esp. femur & occiput), faster & longer bipedal
<daud....@gmail.com> wrote:
On Friday, October 28, 2022 at 12:20:59 AM UTC-4, Daud Deden wrote:
On Friday, October 28, 2022 at 12:13:33 AM UTC-4, Daud Deden wrote:
On Thursday, October 27, 2022 at 10:56:53 PM UTC-4, 69jp...@gmail.com wrote:
On Thu, 27 Oct 2022 16:44:19 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Thursday, October 27, 2022 at 5:53:29 AM UTC-4, 69jp...@gmail.com wrote:
On Thu, 27 Oct 2022 02:17:42 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Wednesday, October 26, 2022 at 7:56:43 PM UTC-4, 69jp...@gmail.com wrote:
On Wed, 26 Oct 2022 03:17:08 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Wednesday, October 26, 2022 at 4:10:49 AM UTC-4, 69jp...@gmail.com wrote:
On Tue, 25 Oct 2022 16:32:06 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Tuesday, October 25, 2022 at 6:59:05 PM UTC-4, 69jp...@gmail.com wrote:
On Tue, 25 Oct 2022 01:18:27 -0700, Trolidan7
<Trol...@eternal-september.org> wrote:
On 10/23/22 11:50 PM, jillery wrote:Watch the cited videos. Erika points out the challenges of going from
Gutsick Gibbon is the Youtube handle of a biological anthropology PhD
student named Erika. Two of her recent videos discuss some of the
latest developments relating to the origins of human bipedalism:
<https://www.youtube.com/watch?v=kbQAgPSHbZE>
The above is a link to a 32-minute video where Erika discusses several
papers relating to Sahelanthropus tchadensis. This fossil is
remarkable in part because it's dated to about 7mya and was found in
central-african Chad, and also because it may be the oldest bipedal
hominin fossil found to date. However, there appears to be strong
disagreement whether the evidence supports bipedalism. >> > > >> >> >> >> >>
<https://www.youtube.com/watch?v=Nwkfkp360ps>
The above is a link to a 22-minute video where Erika discusses several
hypotheses about *why* our ancestors shifted to obligate bipedalism.
She discusses several hypotheses, and presents compelling arguments
for her preferred one.
I tend to think of it as none of the above.
Simply because it is not that easy to stand upright.
When an animal stands upright you need to solve a problem -
how do you keep from falling over forward and backward. >> > > >> >> >> >> >
This might seem simple but it is not because with a four >> > > >> >> >> >> >footed animal the center of gravity forward and backward >> > > >> >> >> >> >is between the front legs and the back legs, and often >> > > >> >> >> >> >that is a greater distance than between the left legs and
the right legs.
quadruped to biped, the differences between upright posture and
bipedalism, and the plausibility of suspensory orthograde posture in
trees as a precursor to bipedalism on the ground.
Some animals that sort of walk on twos have not solved theThat's why humans like big butts, I can not lie.
problem - a kangaroo can hop but in general it can not >> > > >> >> >> >> >stably stand. Either way, in essence, the long hand enables
force to be supplied to the far front and far back to counter
falling forward or backward - the forefoot and big toe are
the front force appliers and the heel is the back force >> > > >> >> >> >> >applier. Then of course there are some animals that might
sort of walk on threes (I am thinking of the Jerboa) - but
humans have an extra problem because they have no tail to
possibly act as an extra walking limb, or at least a balance.
Bigger butt bones, bigger brain bones, initially.
Homo erectus had unusually thick dense femurs and unusually thick dense occiputs (rear skull bone), which counterbalanced the pace over orthogonal bipedal treks on the ground, substituting for the more typical long dense tail of other
slow brachiation x arboreal bipedalism, as in European miocene - pliocene apes and similar to but distinct from faster extant gibbons.S chadensis was imo not a habitual nor obligate terrestrial orthograde biped, nor a part-time knucklewalking terrestrial quadruped, its foramen magnum reflected a more primitive arboreal orthograde bipedalism associated with suspensory@378 cm^3, S. tchadensis' braincase is similar to that of extant
Casually walking while chewing gum, chatting and carrying a squirming child is something only humans could ever do.
chimpanzees and approximately a third the size of modern human brains.
foramen magnum.
Chimps & gorillas became more quadrupedal (partly pronograde terrestrial knucklewalking) while Homo became more bipedal (fully orthograde habitual obligate terrestrial striding), these produced changes of position and orientation of the
hominin & Homo evolution, one which I have already specifically addressed earlier. She and the various authors seem to be unable to comprehend the significance of arboreal habitual bipedalism. The authors do not disagree with my opinion, they are notI am so far sorely disappointed. At around 8:23, Erika intelligently but ignorantly describes the position of the foramen magnum and its significance. To her, bipedalism is terrestrial bipedalism. That is the central flaw in the study of hominoid,After a sneak peek, I see the paper, Postcranial ..., about the femur. I've skimmed it, no change in my thinking. But I'm flexible.Ok, I'd watched half of the 2nd video. I'll watch both tomorrow. I'll certainly learn something, I always do. For now, I stand behind every word I wrote earlier about Homo & Sahelanthropus.Once again, watch the cited video. Erika identifies the paper in the >> > > first few minutes of the first vdeo. But if you watch/listen to all >> > > of both, you might actually learn something.If only there were some way to judge between contrasting opinions...They might be right.The authors of the paper Erika cited disagree with your opinion.
https://carta.anthropogeny.org/moca/topics/foramen-magnum-placement#:~:text=The%20foramen%20magnum%20position%20has,case%20for%20Ardipithecus%20and%20Sahelanthropus.
Parsimony is good.
Please direct me to the author(s) who disagree with what I wrote earlier. I don't know where to start, which vid, which paper... I'll examine inconsistencies (their or mine).
I acknowledge in the first video Erika mostly uses "bipedalism"
without distinction between arboreal and terrestrial. However, her
argument explicitly distinguishes between hominin and panin, and also explicitly mentions terrestrial bipedality once. My understanding is
Erika uses hominin v panin to distinguish terrestrial v arboreal
bipedalism. I could be wrong.
Also, in the second video, Erika explicitly identifies arboreal
bipedalism as an enabling adaptation to terrestrial bipedalism. So to
say she doesn't comprehend its significance is an exaggeration at
least.
Erika is careful for copyright purposes to limit how much of the cited
paper she includes in her video, so I can't say if the paper's authors
make an explicit distinction between arboreal and terrestrial
bipedalism. Someone who has access to the full paper will have to
weigh in on that point.
However, Erika does mention that the paper discusses anatomical
features of the femur (proto linear aspira, gluteal tuberosity, calcar femoral {sp?}), and cortical bone of the ulnae. My understanding is
these features are not present in arboreal bipedal species, and
instead indicate the more robust musculature of terrestrial
bipedalism.
Finally, Erika's expressed reservation with the paper is if the
evidence supports habitual bipedalism. She argues that would inform
whether the common ancestor between hominin and panin was more
human-like or more chimpanzee-like.
On Friday, October 28, 2022 at 4:45:58 AM UTC-4, 69jp...@gmail.com wrote:other bipeds (T rex, giant short faced kangaroo, giant ground sloth, running jesus lizard). This primitive mechanical gyroscope was replaced by genetic software improvements enabling reduced body bone weight (esp. femur & occiput), faster & longer
On Thu, 27 Oct 2022 21:53:46 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Friday, October 28, 2022 at 12:20:59 AM UTC-4, Daud Deden wrote:
On Friday, October 28, 2022 at 12:13:33 AM UTC-4, Daud Deden wrote:
On Thursday, October 27, 2022 at 10:56:53 PM UTC-4, 69jp...@gmail.com wrote:
On Thu, 27 Oct 2022 16:44:19 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Thursday, October 27, 2022 at 5:53:29 AM UTC-4, 69jp...@gmail.com wrote:
On Thu, 27 Oct 2022 02:17:42 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Wednesday, October 26, 2022 at 7:56:43 PM UTC-4, 69jp...@gmail.com wrote:
On Wed, 26 Oct 2022 03:17:08 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Wednesday, October 26, 2022 at 4:10:49 AM UTC-4, 69jp...@gmail.com wrote:
On Tue, 25 Oct 2022 16:32:06 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Tuesday, October 25, 2022 at 6:59:05 PM UTC-4, 69jp...@gmail.com wrote:
On Tue, 25 Oct 2022 01:18:27 -0700, Trolidan7
<Trol...@eternal-september.org> wrote:
On 10/23/22 11:50 PM, jillery wrote:Watch the cited videos. Erika points out the challenges of going from
Gutsick Gibbon is the Youtube handle of a biological anthropology PhD
student named Erika. Two of her recent videos discuss some of the
latest developments relating to the origins of human bipedalism:
<https://www.youtube.com/watch?v=kbQAgPSHbZE>
The above is a link to a 32-minute video where Erika discusses several
papers relating to Sahelanthropus tchadensis. This fossil is
remarkable in part because it's dated to about 7mya and was found in
central-african Chad, and also because it may be the oldest bipedal
hominin fossil found to date. However, there appears to be strong
disagreement whether the evidence supports bipedalism.
<https://www.youtube.com/watch?v=Nwkfkp360ps>
The above is a link to a 22-minute video where Erika discusses several
hypotheses about *why* our ancestors shifted to obligate bipedalism.
She discusses several hypotheses, and presents compelling arguments
for her preferred one.
I tend to think of it as none of the above.
Simply because it is not that easy to stand upright. >> > > >> >> >> >> >
When an animal stands upright you need to solve a problem -
how do you keep from falling over forward and backward.
This might seem simple but it is not because with a four
footed animal the center of gravity forward and backward
is between the front legs and the back legs, and often >> > > >> >> >> >> >that is a greater distance than between the left legs and
the right legs.
quadruped to biped, the differences between upright posture and
bipedalism, and the plausibility of suspensory orthograde posture in
trees as a precursor to bipedalism on the ground.
Some animals that sort of walk on twos have not solved theThat's why humans like big butts, I can not lie.
problem - a kangaroo can hop but in general it can not >> > > >> >> >> >> >stably stand. Either way, in essence, the long hand enables
force to be supplied to the far front and far back to counter
falling forward or backward - the forefoot and big toe are
the front force appliers and the heel is the back force
applier. Then of course there are some animals that might
sort of walk on threes (I am thinking of the Jerboa) - but
humans have an extra problem because they have no tail to
possibly act as an extra walking limb, or at least a balance.
Bigger butt bones, bigger brain bones, initially.
Homo erectus had unusually thick dense femurs and unusually thick dense occiputs (rear skull bone), which counterbalanced the pace over orthogonal bipedal treks on the ground, substituting for the more typical long dense tail of
slow brachiation x arboreal bipedalism, as in European miocene - pliocene apes and similar to but distinct from faster extant gibbons.S chadensis was imo not a habitual nor obligate terrestrial orthograde biped, nor a part-time knucklewalking terrestrial quadruped, its foramen magnum reflected a more primitive arboreal orthograde bipedalism associated with suspensory@378 cm^3, S. tchadensis' braincase is similar to that of extant
Casually walking while chewing gum, chatting and carrying a squirming child is something only humans could ever do.
chimpanzees and approximately a third the size of modern human brains.
foramen magnum.
Chimps & gorillas became more quadrupedal (partly pronograde terrestrial knucklewalking) while Homo became more bipedal (fully orthograde habitual obligate terrestrial striding), these produced changes of position and orientation of the
hominin & Homo evolution, one which I have already specifically addressed earlier. She and the various authors seem to be unable to comprehend the significance of arboreal habitual bipedalism. The authors do not disagree with my opinion, they are notI am so far sorely disappointed. At around 8:23, Erika intelligently but ignorantly describes the position of the foramen magnum and its significance. To her, bipedalism is terrestrial bipedalism. That is the central flaw in the study of hominoid,After a sneak peek, I see the paper, Postcranial ..., about the femur. I've skimmed it, no change in my thinking. But I'm flexible.Ok, I'd watched half of the 2nd video. I'll watch both tomorrow. I'll certainly learn something, I always do. For now, I stand behind every word I wrote earlier about Homo & Sahelanthropus.Once again, watch the cited video. Erika identifies the paper in theIf only there were some way to judge between contrasting opinions...They might be right.The authors of the paper Erika cited disagree with your opinion.
https://carta.anthropogeny.org/moca/topics/foramen-magnum-placement#:~:text=The%20foramen%20magnum%20position%20has,case%20for%20Ardipithecus%20and%20Sahelanthropus.
Parsimony is good.
Please direct me to the author(s) who disagree with what I wrote earlier. I don't know where to start, which vid, which paper... I'll examine inconsistencies (their or mine).
first few minutes of the first vdeo. But if you watch/listen to all >> > > of both, you might actually learn something.
There's also this: https://bmcgenomics.biomedcentral.com/articles/10.1186/s12864-022-08828-7I acknowledge in the first video Erika mostly uses "bipedalism"
without distinction between arboreal and terrestrial. However, her argument explicitly distinguishes between hominin and panin, and also explicitly mentions terrestrial bipedality once. My understanding is
Erika uses hominin v panin to distinguish terrestrial v arboreal bipedalism. I could be wrong.
Also, in the second video, Erika explicitly identifies arboreal
bipedalism as an enabling adaptation to terrestrial bipedalism. So to
say she doesn't comprehend its significance is an exaggeration at
least.
Erika is careful for copyright purposes to limit how much of the cited paper she includes in her video, so I can't say if the paper's authors make an explicit distinction between arboreal and terrestrial
bipedalism. Someone who has access to the full paper will have to
weigh in on that point.
However, Erika does mention that the paper discusses anatomical
features of the femur (proto linear aspira, gluteal tuberosity, calcar femoral {sp?}), and cortical bone of the ulnae. My understanding is
these features are not present in arboreal bipedal species, and
instead indicate the more robust musculature of terrestrial
bipedalism.
Finally, Erika's expressed reservation with the paper is if theMy written response was lost. Damn. 15 sentences evaporated.
evidence supports habitual bipedalism. She argues that would inform whether the common ancestor between hominin and panin was more
human-like or more chimpanzee-like.
The data graphs have nothing about hylobatids or macaques, so are worthless. Near the end of video one, Erika talks about 'bipedal or arboreal', revealing that she still doesn't get it.
J: "these features are not present in arboreal bipedal species" Extant knucklewalking apes which sleep in bowl nests? Humans are gracile terrestrial bipeds.
Not even mentioned: gibbons and humans share long achilles tendon and long lower back, opposite of extant great apes.
On Friday, October 28, 2022 at 5:45:10 PM UTC-4, Daud Deden wrote:other bipeds (T rex, giant short faced kangaroo, giant ground sloth, running jesus lizard). This primitive mechanical gyroscope was replaced by genetic software improvements enabling reduced body bone weight (esp. femur & occiput), faster & longer
On Friday, October 28, 2022 at 4:45:58 AM UTC-4, 69jp...@gmail.com wrote: >> > On Thu, 27 Oct 2022 21:53:46 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Friday, October 28, 2022 at 12:20:59 AM UTC-4, Daud Deden wrote:
On Friday, October 28, 2022 at 12:13:33 AM UTC-4, Daud Deden wrote:
On Thursday, October 27, 2022 at 10:56:53 PM UTC-4, 69jp...@gmail.com wrote:
On Thu, 27 Oct 2022 16:44:19 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Thursday, October 27, 2022 at 5:53:29 AM UTC-4, 69jp...@gmail.com wrote:
On Thu, 27 Oct 2022 02:17:42 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Wednesday, October 26, 2022 at 7:56:43 PM UTC-4, 69jp...@gmail.com wrote:
On Wed, 26 Oct 2022 03:17:08 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Wednesday, October 26, 2022 at 4:10:49 AM UTC-4, 69jp...@gmail.com wrote:
On Tue, 25 Oct 2022 16:32:06 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Tuesday, October 25, 2022 at 6:59:05 PM UTC-4, 69jp...@gmail.com wrote:
On Tue, 25 Oct 2022 01:18:27 -0700, Trolidan7
<Trol...@eternal-september.org> wrote:
On 10/23/22 11:50 PM, jillery wrote:Watch the cited videos. Erika points out the challenges of going from
Gutsick Gibbon is the Youtube handle of a biological anthropology PhD
student named Erika. Two of her recent videos discuss some of the
latest developments relating to the origins of human bipedalism:
<https://www.youtube.com/watch?v=kbQAgPSHbZE>
The above is a link to a 32-minute video where Erika discusses several
papers relating to Sahelanthropus tchadensis. This fossil is
remarkable in part because it's dated to about 7mya and was found in
central-african Chad, and also because it may be the oldest bipedal
hominin fossil found to date. However, there appears to be strong
disagreement whether the evidence supports bipedalism.
<https://www.youtube.com/watch?v=Nwkfkp360ps>
The above is a link to a 22-minute video where Erika discusses several
hypotheses about *why* our ancestors shifted to obligate bipedalism.
She discusses several hypotheses, and presents compelling arguments
for her preferred one.
I tend to think of it as none of the above.
Simply because it is not that easy to stand upright. >> > >> > > >> >> >> >> >
When an animal stands upright you need to solve a problem -
how do you keep from falling over forward and backward.
This might seem simple but it is not because with a four
footed animal the center of gravity forward and backward
is between the front legs and the back legs, and often
that is a greater distance than between the left legs and
the right legs.
quadruped to biped, the differences between upright posture and
bipedalism, and the plausibility of suspensory orthograde posture in
trees as a precursor to bipedalism on the ground.
Some animals that sort of walk on twos have not solved theThat's why humans like big butts, I can not lie.
problem - a kangaroo can hop but in general it can not
stably stand. Either way, in essence, the long hand enables
force to be supplied to the far front and far back to counter
falling forward or backward - the forefoot and big toe are
the front force appliers and the heel is the back force
applier. Then of course there are some animals that might
sort of walk on threes (I am thinking of the Jerboa) - but
humans have an extra problem because they have no tail to
possibly act as an extra walking limb, or at least a balance.
Bigger butt bones, bigger brain bones, initially.
Homo erectus had unusually thick dense femurs and unusually thick dense occiputs (rear skull bone), which counterbalanced the pace over orthogonal bipedal treks on the ground, substituting for the more typical long dense tail of
slow brachiation x arboreal bipedalism, as in European miocene - pliocene apes and similar to but distinct from faster extant gibbons.S chadensis was imo not a habitual nor obligate terrestrial orthograde biped, nor a part-time knucklewalking terrestrial quadruped, its foramen magnum reflected a more primitive arboreal orthograde bipedalism associated with suspensory@378 cm^3, S. tchadensis' braincase is similar to that of extant
Casually walking while chewing gum, chatting and carrying a squirming child is something only humans could ever do.
chimpanzees and approximately a third the size of modern human brains.
the foramen magnum.
Chimps & gorillas became more quadrupedal (partly pronograde terrestrial knucklewalking) while Homo became more bipedal (fully orthograde habitual obligate terrestrial striding), these produced changes of position and orientation of
hominin & Homo evolution, one which I have already specifically addressed earlier. She and the various authors seem to be unable to comprehend the significance of arboreal habitual bipedalism. The authors do not disagree with my opinion, they are notI am so far sorely disappointed. At around 8:23, Erika intelligently but ignorantly describes the position of the foramen magnum and its significance. To her, bipedalism is terrestrial bipedalism. That is the central flaw in the study of hominoid,After a sneak peek, I see the paper, Postcranial ..., about the femur. I've skimmed it, no change in my thinking. But I'm flexible.Ok, I'd watched half of the 2nd video. I'll watch both tomorrow. I'll certainly learn something, I always do. For now, I stand behind every word I wrote earlier about Homo & Sahelanthropus.Once again, watch the cited video. Erika identifies the paper in theIf only there were some way to judge between contrasting opinions...They might be right.The authors of the paper Erika cited disagree with your opinion.
https://carta.anthropogeny.org/moca/topics/foramen-magnum-placement#:~:text=The%20foramen%20magnum%20position%20has,case%20for%20Ardipithecus%20and%20Sahelanthropus.
Parsimony is good.
Please direct me to the author(s) who disagree with what I wrote earlier. I don't know where to start, which vid, which paper... I'll examine inconsistencies (their or mine).
first few minutes of the first vdeo. But if you watch/listen to all
of both, you might actually learn something.
I acknowledge in the first video Erika mostly uses "bipedalism"My written response was lost. Damn. 15 sentences evaporated.
without distinction between arboreal and terrestrial. However, her
argument explicitly distinguishes between hominin and panin, and also
explicitly mentions terrestrial bipedality once. My understanding is
Erika uses hominin v panin to distinguish terrestrial v arboreal
bipedalism. I could be wrong.
Also, in the second video, Erika explicitly identifies arboreal
bipedalism as an enabling adaptation to terrestrial bipedalism. So to
say she doesn't comprehend its significance is an exaggeration at
least.
Erika is careful for copyright purposes to limit how much of the cited
paper she includes in her video, so I can't say if the paper's authors
make an explicit distinction between arboreal and terrestrial
bipedalism. Someone who has access to the full paper will have to
weigh in on that point.
However, Erika does mention that the paper discusses anatomical
features of the femur (proto linear aspira, gluteal tuberosity, calcar
femoral {sp?}), and cortical bone of the ulnae. My understanding is
these features are not present in arboreal bipedal species, and
instead indicate the more robust musculature of terrestrial
bipedalism.
Finally, Erika's expressed reservation with the paper is if the
evidence supports habitual bipedalism. She argues that would inform
whether the common ancestor between hominin and panin was more
human-like or more chimpanzee-like.
The data graphs have nothing about hylobatids or macaques, so are worthless.
Near the end of video one, Erika talks about 'bipedal or arboreal', revealing that she still doesn't get it.
J: "these features are not present in arboreal bipedal species"
Extant knucklewalking apes which sleep in bowl nests? Humans are gracile terrestrial bipeds.
Not even mentioned: gibbons and humans share long achilles tendon and long lower back, opposite of extant great apes.
There's also this: https://bmcgenomics.biomedcentral.com/articles/10.1186/s12864-022-08828-7
On Fri, 28 Oct 2022 21:26:43 -0700 (PDT), Daud Dedenother bipeds (T rex, giant short faced kangaroo, giant ground sloth, running jesus lizard). This primitive mechanical gyroscope was replaced by genetic software improvements enabling reduced body bone weight (esp. femur & occiput), faster & longer
<daud....@gmail.com> wrote:
On Friday, October 28, 2022 at 5:45:10 PM UTC-4, Daud Deden wrote:
On Friday, October 28, 2022 at 4:45:58 AM UTC-4, 69jp...@gmail.com wrote: >> > On Thu, 27 Oct 2022 21:53:46 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Friday, October 28, 2022 at 12:20:59 AM UTC-4, Daud Deden wrote:
On Friday, October 28, 2022 at 12:13:33 AM UTC-4, Daud Deden wrote: >> > >> > On Thursday, October 27, 2022 at 10:56:53 PM UTC-4, 69jp...@gmail.com wrote:
On Thu, 27 Oct 2022 16:44:19 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Thursday, October 27, 2022 at 5:53:29 AM UTC-4, 69jp...@gmail.com wrote:
On Thu, 27 Oct 2022 02:17:42 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Wednesday, October 26, 2022 at 7:56:43 PM UTC-4, 69jp...@gmail.com wrote:
On Wed, 26 Oct 2022 03:17:08 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Wednesday, October 26, 2022 at 4:10:49 AM UTC-4, 69jp...@gmail.com wrote:
On Tue, 25 Oct 2022 16:32:06 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Tuesday, October 25, 2022 at 6:59:05 PM UTC-4, 69jp...@gmail.com wrote:
On Tue, 25 Oct 2022 01:18:27 -0700, Trolidan7
<Trol...@eternal-september.org> wrote:
On 10/23/22 11:50 PM, jillery wrote:Watch the cited videos. Erika points out the challenges of going from
Gutsick Gibbon is the Youtube handle of a biological anthropology PhD
student named Erika. Two of her recent videos discuss some of the
latest developments relating to the origins of human bipedalism:
<https://www.youtube.com/watch?v=kbQAgPSHbZE>
The above is a link to a 32-minute video where Erika discusses several
papers relating to Sahelanthropus tchadensis. This fossil is
remarkable in part because it's dated to about 7mya and was found in
central-african Chad, and also because it may be the oldest bipedal
hominin fossil found to date. However, there appears to be strong
disagreement whether the evidence supports bipedalism.
<https://www.youtube.com/watch?v=Nwkfkp360ps>
The above is a link to a 22-minute video where Erika discusses several
hypotheses about *why* our ancestors shifted to obligate bipedalism.
She discusses several hypotheses, and presents compelling arguments
for her preferred one.
I tend to think of it as none of the above.
Simply because it is not that easy to stand upright.
When an animal stands upright you need to solve a problem -
how do you keep from falling over forward and backward.
This might seem simple but it is not because with a four
footed animal the center of gravity forward and backward
is between the front legs and the back legs, and often
that is a greater distance than between the left legs and
the right legs.
quadruped to biped, the differences between upright posture and
bipedalism, and the plausibility of suspensory orthograde posture in
trees as a precursor to bipedalism on the ground.
Some animals that sort of walk on twos have not solved theThat's why humans like big butts, I can not lie.
problem - a kangaroo can hop but in general it can not
stably stand. Either way, in essence, the long hand enables
force to be supplied to the far front and far back to counter
falling forward or backward - the forefoot and big toe are
the front force appliers and the heel is the back force
applier. Then of course there are some animals that might
sort of walk on threes (I am thinking of the Jerboa) - but
humans have an extra problem because they have no tail to
possibly act as an extra walking limb, or at least a balance.
Bigger butt bones, bigger brain bones, initially.
Homo erectus had unusually thick dense femurs and unusually thick dense occiputs (rear skull bone), which counterbalanced the pace over orthogonal bipedal treks on the ground, substituting for the more typical long dense tail of
suspensory slow brachiation x arboreal bipedalism, as in European miocene - pliocene apes and similar to but distinct from faster extant gibbons.S chadensis was imo not a habitual nor obligate terrestrial orthograde biped, nor a part-time knucklewalking terrestrial quadruped, its foramen magnum reflected a more primitive arboreal orthograde bipedalism associated with@378 cm^3, S. tchadensis' braincase is similar to that of extant
Casually walking while chewing gum, chatting and carrying a squirming child is something only humans could ever do.
chimpanzees and approximately a third the size of modern human brains.
the foramen magnum.
Chimps & gorillas became more quadrupedal (partly pronograde terrestrial knucklewalking) while Homo became more bipedal (fully orthograde habitual obligate terrestrial striding), these produced changes of position and orientation of
hominin & Homo evolution, one which I have already specifically addressed earlier. She and the various authors seem to be unable to comprehend the significance of arboreal habitual bipedalism. The authors do not disagree with my opinion, they are notI am so far sorely disappointed. At around 8:23, Erika intelligently but ignorantly describes the position of the foramen magnum and its significance. To her, bipedalism is terrestrial bipedalism. That is the central flaw in the study of hominoid,After a sneak peek, I see the paper, Postcranial ..., about the femur. I've skimmed it, no change in my thinking. But I'm flexible.Ok, I'd watched half of the 2nd video. I'll watch both tomorrow. I'll certainly learn something, I always do. For now, I stand behind every word I wrote earlier about Homo & Sahelanthropus.Once again, watch the cited video. Erika identifies the paper in theIf only there were some way to judge between contrasting opinions...They might be right.The authors of the paper Erika cited disagree with your opinion.
https://carta.anthropogeny.org/moca/topics/foramen-magnum-placement#:~:text=The%20foramen%20magnum%20position%20has,case%20for%20Ardipithecus%20and%20Sahelanthropus.
Parsimony is good.
Please direct me to the author(s) who disagree with what I wrote earlier. I don't know where to start, which vid, which paper... I'll examine inconsistencies (their or mine).
first few minutes of the first vdeo. But if you watch/listen to all
of both, you might actually learn something.
Been there, done that. I agree it suks.I acknowledge in the first video Erika mostly uses "bipedalism"My written response was lost. Damn. 15 sentences evaporated.
without distinction between arboreal and terrestrial. However, her
argument explicitly distinguishes between hominin and panin, and also >> > explicitly mentions terrestrial bipedality once. My understanding is
Erika uses hominin v panin to distinguish terrestrial v arboreal
bipedalism. I could be wrong.
Also, in the second video, Erika explicitly identifies arboreal
bipedalism as an enabling adaptation to terrestrial bipedalism. So to >> > say she doesn't comprehend its significance is an exaggeration at
least.
Erika is careful for copyright purposes to limit how much of the cited >> > paper she includes in her video, so I can't say if the paper's authors >> > make an explicit distinction between arboreal and terrestrial
bipedalism. Someone who has access to the full paper will have to
weigh in on that point.
However, Erika does mention that the paper discusses anatomical
features of the femur (proto linear aspira, gluteal tuberosity, calcar >> > femoral {sp?}), and cortical bone of the ulnae. My understanding is
these features are not present in arboreal bipedal species, and
instead indicate the more robust musculature of terrestrial
bipedalism.
Finally, Erika's expressed reservation with the paper is if the
evidence supports habitual bipedalism. She argues that would inform
whether the common ancestor between hominin and panin was more
human-like or more chimpanzee-like.
I can't find where Erika says that,The data graphs have nothing about hylobatids or macaques, so are worthless.
Near the end of video one, Erika talks about 'bipedal or arboreal', revealing that she still doesn't get it.
J: "these features are not present in arboreal bipedal species"
the 4 anatomical features of the tibia [femur] and ulnae I mention above. What
arboreal bipedal species do you know with these features?
Extant knucklewalking apes which sleep in bowl nests? Humans are gracile terrestrial bipeds.Do the cited papers mention these things? If not, that would explain
Not even mentioned: gibbons and humans share long achilles tendon and long lower back, opposite of extant great apes.
why Erika doesn't either.
H/P split estimated timing .9ma is much later than MSC (Medit. & Red Sea dried out); H erectus bridged the est. date, so would have had 24, not 23 like Hs. I doubt their estimate.There's also this: https://bmcgenomics.biomedcentral.com/articles/10.1186/s12864-022-08828-7Not sure what chromosome 2 fusion has to do with this topic. Please elaborate.
On Saturday, October 29, 2022 at 2:11:43 AM UTC-4, 69jp...@gmail.com wrote:other bipeds (T rex, giant short faced kangaroo, giant ground sloth, running jesus lizard). This primitive mechanical gyroscope was replaced by genetic software improvements enabling reduced body bone weight (esp. femur & occiput), faster & longer
On Fri, 28 Oct 2022 21:26:43 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Friday, October 28, 2022 at 5:45:10 PM UTC-4, Daud Deden wrote:
On Friday, October 28, 2022 at 4:45:58 AM UTC-4, 69jp...@gmail.com wrote:
On Thu, 27 Oct 2022 21:53:46 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Friday, October 28, 2022 at 12:20:59 AM UTC-4, Daud Deden wrote: >> >> > >> On Friday, October 28, 2022 at 12:13:33 AM UTC-4, Daud Deden wrote: >> >> > >> > On Thursday, October 27, 2022 at 10:56:53 PM UTC-4, 69jp...@gmail.com wrote:
On Thu, 27 Oct 2022 16:44:19 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Thursday, October 27, 2022 at 5:53:29 AM UTC-4, 69jp...@gmail.com wrote:
On Thu, 27 Oct 2022 02:17:42 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Wednesday, October 26, 2022 at 7:56:43 PM UTC-4, 69jp...@gmail.com wrote:
On Wed, 26 Oct 2022 03:17:08 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Wednesday, October 26, 2022 at 4:10:49 AM UTC-4, 69jp...@gmail.com wrote:
On Tue, 25 Oct 2022 16:32:06 -0700 (PDT), Daud Deden >> >> > >> > > >> >> >> <daud....@gmail.com> wrote:
On Tuesday, October 25, 2022 at 6:59:05 PM UTC-4, 69jp...@gmail.com wrote:
On Tue, 25 Oct 2022 01:18:27 -0700, Trolidan7
<Trol...@eternal-september.org> wrote:
On 10/23/22 11:50 PM, jillery wrote:Watch the cited videos. Erika points out the challenges of going from
Gutsick Gibbon is the Youtube handle of a biological anthropology PhD
student named Erika. Two of her recent videos discuss some of the
latest developments relating to the origins of human bipedalism:
<https://www.youtube.com/watch?v=kbQAgPSHbZE>
The above is a link to a 32-minute video where Erika discusses several
papers relating to Sahelanthropus tchadensis. This fossil is
remarkable in part because it's dated to about 7mya and was found in
central-african Chad, and also because it may be the oldest bipedal
hominin fossil found to date. However, there appears to be strong
disagreement whether the evidence supports bipedalism.
<https://www.youtube.com/watch?v=Nwkfkp360ps>
The above is a link to a 22-minute video where Erika discusses several
hypotheses about *why* our ancestors shifted to obligate bipedalism.
She discusses several hypotheses, and presents compelling arguments
for her preferred one.
I tend to think of it as none of the above.
Simply because it is not that easy to stand upright.
When an animal stands upright you need to solve a problem -
how do you keep from falling over forward and backward.
This might seem simple but it is not because with a four
footed animal the center of gravity forward and backward
is between the front legs and the back legs, and often
that is a greater distance than between the left legs and
the right legs.
quadruped to biped, the differences between upright posture and
bipedalism, and the plausibility of suspensory orthograde posture in
trees as a precursor to bipedalism on the ground. >> >> > >> > > >> >> >> >> >Some animals that sort of walk on twos have not solved the
problem - a kangaroo can hop but in general it can notThat's why humans like big butts, I can not lie.
stably stand. Either way, in essence, the long hand enables
force to be supplied to the far front and far back to counter
falling forward or backward - the forefoot and big toe are
the front force appliers and the heel is the back force
applier. Then of course there are some animals that might
sort of walk on threes (I am thinking of the Jerboa) - but
humans have an extra problem because they have no tail to
possibly act as an extra walking limb, or at least a balance.
Bigger butt bones, bigger brain bones, initially.
Homo erectus had unusually thick dense femurs and unusually thick dense occiputs (rear skull bone), which counterbalanced the pace over orthogonal bipedal treks on the ground, substituting for the more typical long dense tail of
suspensory slow brachiation x arboreal bipedalism, as in European miocene - pliocene apes and similar to but distinct from faster extant gibbons.S chadensis was imo not a habitual nor obligate terrestrial orthograde biped, nor a part-time knucklewalking terrestrial quadruped, its foramen magnum reflected a more primitive arboreal orthograde bipedalism associated with@378 cm^3, S. tchadensis' braincase is similar to that of extant
Casually walking while chewing gum, chatting and carrying a squirming child is something only humans could ever do.
chimpanzees and approximately a third the size of modern human brains.
the foramen magnum.
Chimps & gorillas became more quadrupedal (partly pronograde terrestrial knucklewalking) while Homo became more bipedal (fully orthograde habitual obligate terrestrial striding), these produced changes of position and orientation of
hominoid, hominin & Homo evolution, one which I have already specifically addressed earlier. She and the various authors seem to be unable to comprehend the significance of arboreal habitual bipedalism. The authors do not disagree with my opinion, theyI am so far sorely disappointed. At around 8:23, Erika intelligently but ignorantly describes the position of the foramen magnum and its significance. To her, bipedalism is terrestrial bipedalism. That is the central flaw in the study ofAfter a sneak peek, I see the paper, Postcranial ..., about the femur. I've skimmed it, no change in my thinking. But I'm flexible.Ok, I'd watched half of the 2nd video. I'll watch both tomorrow. I'll certainly learn something, I always do. For now, I stand behind every word I wrote earlier about Homo & Sahelanthropus.Once again, watch the cited video. Erika identifies the paper in theIf only there were some way to judge between contrasting opinions...They might be right.The authors of the paper Erika cited disagree with your opinion.
https://carta.anthropogeny.org/moca/topics/foramen-magnum-placement#:~:text=The%20foramen%20magnum%20position%20has,case%20for%20Ardipithecus%20and%20Sahelanthropus.
Parsimony is good.
Please direct me to the author(s) who disagree with what I wrote earlier. I don't know where to start, which vid, which paper... I'll examine inconsistencies (their or mine).
first few minutes of the first vdeo. But if you watch/listen to all
of both, you might actually learn something.
Been there, done that. I agree it suks.I acknowledge in the first video Erika mostly uses "bipedalism"My written response was lost. Damn. 15 sentences evaporated.
without distinction between arboreal and terrestrial. However, her
argument explicitly distinguishes between hominin and panin, and also >> >> > explicitly mentions terrestrial bipedality once. My understanding is >> >> > Erika uses hominin v panin to distinguish terrestrial v arboreal
bipedalism. I could be wrong.
Also, in the second video, Erika explicitly identifies arboreal
bipedalism as an enabling adaptation to terrestrial bipedalism. So to >> >> > say she doesn't comprehend its significance is an exaggeration at
least.
Erika is careful for copyright purposes to limit how much of the cited >> >> > paper she includes in her video, so I can't say if the paper's authors >> >> > make an explicit distinction between arboreal and terrestrial
bipedalism. Someone who has access to the full paper will have to
weigh in on that point.
However, Erika does mention that the paper discusses anatomical
features of the femur (proto linear aspira, gluteal tuberosity, calcar >> >> > femoral {sp?}), and cortical bone of the ulnae. My understanding is
these features are not present in arboreal bipedal species, and
instead indicate the more robust musculature of terrestrial
bipedalism.
Finally, Erika's expressed reservation with the paper is if the
evidence supports habitual bipedalism. She argues that would inform
whether the common ancestor between hominin and panin was more
human-like or more chimpanzee-like.
I can't find where Erika says that,The data graphs have nothing about hylobatids or macaques, so are worthless.
Near the end of video one, Erika talks about 'bipedal or arboreal', revealing that she still doesn't get it.
J: "these features are not present in arboreal bipedal species"
Possibly video 2.
but I suspect she's referring to
the 4 anatomical features of the tibia [femur] and ulnae I mention above. What
arboreal bipedal species do you know with these features?
All, in a spectrum, Homo at one end, arboreals the other.
Extant knucklewalking apes which sleep in bowl nests? Humans are gracile terrestrial bipeds.Do the cited papers mention these things? If not, that would explain
Not even mentioned: gibbons and humans share long achilles tendon and long lower back, opposite of extant great apes.
why Erika doesn't either.
*Human bipedalism* cannot be *explained* without it. (It can be discussed & lectured, but not explained.) Picking out a few unique features and ignoring others doesn't explain anything.
H/P split estimated timing .9ma is much later than MSC (Medit. & Red Sea dried out); H erectus bridged the est. date, so would have had 24, not 23 like Hs. I doubt their estimate.There's also this: https://bmcgenomics.biomedcentral.com/articles/10.1186/s12864-022-08828-7Not sure what chromosome 2 fusion has to do with this topic. Please
elaborate.
On Sat, 29 Oct 2022 05:26:51 -0700 (PDT), Daud Dedenof other bipeds (T rex, giant short faced kangaroo, giant ground sloth, running jesus lizard). This primitive mechanical gyroscope was replaced by genetic software improvements enabling reduced body bone weight (esp. femur & occiput), faster & longer
<daud....@gmail.com> wrote:
On Saturday, October 29, 2022 at 2:11:43 AM UTC-4, 69jp...@gmail.com wrote: >> On Fri, 28 Oct 2022 21:26:43 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Friday, October 28, 2022 at 5:45:10 PM UTC-4, Daud Deden wrote:
On Friday, October 28, 2022 at 4:45:58 AM UTC-4, 69jp...@gmail.com wrote:
On Thu, 27 Oct 2022 21:53:46 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Friday, October 28, 2022 at 12:20:59 AM UTC-4, Daud Deden wrote: >> >> > >> On Friday, October 28, 2022 at 12:13:33 AM UTC-4, Daud Deden wrote:
On Thursday, October 27, 2022 at 10:56:53 PM UTC-4, 69jp...@gmail.com wrote:
On Thu, 27 Oct 2022 16:44:19 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Thursday, October 27, 2022 at 5:53:29 AM UTC-4, 69jp...@gmail.com wrote:
On Thu, 27 Oct 2022 02:17:42 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Wednesday, October 26, 2022 at 7:56:43 PM UTC-4, 69jp...@gmail.com wrote:
On Wed, 26 Oct 2022 03:17:08 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Wednesday, October 26, 2022 at 4:10:49 AM UTC-4, 69jp...@gmail.com wrote:
On Tue, 25 Oct 2022 16:32:06 -0700 (PDT), Daud Deden >> >> > >> > > >> >> >> <daud....@gmail.com> wrote:
On Tuesday, October 25, 2022 at 6:59:05 PM UTC-4, 69jp...@gmail.com wrote:
On Tue, 25 Oct 2022 01:18:27 -0700, Trolidan7Bigger butt bones, bigger brain bones, initially. >> >> > >> > > >> >> >> >Homo erectus had unusually thick dense femurs and unusually thick dense occiputs (rear skull bone), which counterbalanced the pace over orthogonal bipedal treks on the ground, substituting for the more typical long dense tail
<Trol...@eternal-september.org> wrote:
On 10/23/22 11:50 PM, jillery wrote:Watch the cited videos. Erika points out the challenges of going from
Gutsick Gibbon is the Youtube handle of a biological anthropology PhD
student named Erika. Two of her recent videos discuss some of the
latest developments relating to the origins of human bipedalism:
<https://www.youtube.com/watch?v=kbQAgPSHbZE> >> >> > >> > > >> >> >> >> >>
The above is a link to a 32-minute video where Erika discusses several
papers relating to Sahelanthropus tchadensis. This fossil is
remarkable in part because it's dated to about 7mya and was found in
central-african Chad, and also because it may be the oldest bipedal
hominin fossil found to date. However, there appears to be strong
disagreement whether the evidence supports bipedalism.
<https://www.youtube.com/watch?v=Nwkfkp360ps> >> >> > >> > > >> >> >> >> >>
The above is a link to a 22-minute video where Erika discusses several
hypotheses about *why* our ancestors shifted to obligate bipedalism.
She discusses several hypotheses, and presents compelling arguments
for her preferred one.
I tend to think of it as none of the above.
Simply because it is not that easy to stand upright.
When an animal stands upright you need to solve a problem -
how do you keep from falling over forward and backward.
This might seem simple but it is not because with a four
footed animal the center of gravity forward and backward
is between the front legs and the back legs, and often
that is a greater distance than between the left legs and
the right legs.
quadruped to biped, the differences between upright posture and
bipedalism, and the plausibility of suspensory orthograde posture in
trees as a precursor to bipedalism on the ground. >> >> > >> > > >> >> >> >> >Some animals that sort of walk on twos have not solved the
problem - a kangaroo can hop but in general it can notThat's why humans like big butts, I can not lie. >> >> > >> > > >> >> >> >
stably stand. Either way, in essence, the long hand enables
force to be supplied to the far front and far back to counter
falling forward or backward - the forefoot and big toe are
the front force appliers and the heel is the back force
applier. Then of course there are some animals that might
sort of walk on threes (I am thinking of the Jerboa) - but
humans have an extra problem because they have no tail to
possibly act as an extra walking limb, or at least a balance.
suspensory slow brachiation x arboreal bipedalism, as in European miocene - pliocene apes and similar to but distinct from faster extant gibbons.S chadensis was imo not a habitual nor obligate terrestrial orthograde biped, nor a part-time knucklewalking terrestrial quadruped, its foramen magnum reflected a more primitive arboreal orthograde bipedalism associated with@378 cm^3, S. tchadensis' braincase is similar to that of extant
Casually walking while chewing gum, chatting and carrying a squirming child is something only humans could ever do.
chimpanzees and approximately a third the size of modern human brains.
of the foramen magnum.
Chimps & gorillas became more quadrupedal (partly pronograde terrestrial knucklewalking) while Homo became more bipedal (fully orthograde habitual obligate terrestrial striding), these produced changes of position and orientation
hominoid, hominin & Homo evolution, one which I have already specifically addressed earlier. She and the various authors seem to be unable to comprehend the significance of arboreal habitual bipedalism. The authors do not disagree with my opinion, theyI am so far sorely disappointed. At around 8:23, Erika intelligently but ignorantly describes the position of the foramen magnum and its significance. To her, bipedalism is terrestrial bipedalism. That is the central flaw in the study ofAfter a sneak peek, I see the paper, Postcranial ..., about the femur. I've skimmed it, no change in my thinking. But I'm flexible.Ok, I'd watched half of the 2nd video. I'll watch both tomorrow. I'll certainly learn something, I always do. For now, I stand behind every word I wrote earlier about Homo & Sahelanthropus.Once again, watch the cited video. Erika identifies the paper in theIf only there were some way to judge between contrasting opinions...They might be right.The authors of the paper Erika cited disagree with your opinion.
https://carta.anthropogeny.org/moca/topics/foramen-magnum-placement#:~:text=The%20foramen%20magnum%20position%20has,case%20for%20Ardipithecus%20and%20Sahelanthropus.
Parsimony is good.
Please direct me to the author(s) who disagree with what I wrote earlier. I don't know where to start, which vid, which paper... I'll examine inconsistencies (their or mine).
first few minutes of the first vdeo. But if you watch/listen to all
of both, you might actually learn something.
Been there, done that. I agree it suks.I acknowledge in the first video Erika mostly uses "bipedalism"My written response was lost. Damn. 15 sentences evaporated.
without distinction between arboreal and terrestrial. However, her >> >> > argument explicitly distinguishes between hominin and panin, and also
explicitly mentions terrestrial bipedality once. My understanding is >> >> > Erika uses hominin v panin to distinguish terrestrial v arboreal
bipedalism. I could be wrong.
Also, in the second video, Erika explicitly identifies arboreal
bipedalism as an enabling adaptation to terrestrial bipedalism. So to
say she doesn't comprehend its significance is an exaggeration at
least.
Erika is careful for copyright purposes to limit how much of the cited
paper she includes in her video, so I can't say if the paper's authors
make an explicit distinction between arboreal and terrestrial
bipedalism. Someone who has access to the full paper will have to
weigh in on that point.
However, Erika does mention that the paper discusses anatomical
features of the femur (proto linear aspira, gluteal tuberosity, calcar
femoral {sp?}), and cortical bone of the ulnae. My understanding is >> >> > these features are not present in arboreal bipedal species, and
instead indicate the more robust musculature of terrestrial
bipedalism.
Finally, Erika's expressed reservation with the paper is if the
evidence supports habitual bipedalism. She argues that would inform >> >> > whether the common ancestor between hominin and panin was more
human-like or more chimpanzee-like.
I can't find where Erika says that,The data graphs have nothing about hylobatids or macaques, so are worthless.
Near the end of video one, Erika talks about 'bipedal or arboreal', revealing that she still doesn't get it.
J: "these features are not present in arboreal bipedal species"
Possibly video 2.I can't find your quote in either video. Why don't you know where you
got that quote?
but I suspect she's referring to
the 4 anatomical features of the tibia [femur] and ulnae I mention above. What
arboreal bipedal species do you know with these features?
All, in a spectrum, Homo at one end, arboreals the other.I am hard-pressed to describe extant humans as arboreal bipeds.
are likely descended from arboreal bipeds, but it's a derived characteristic.
Extant knucklewalking apes which sleep in bowl nests? Humans are gracile terrestrial bipeds.Do the cited papers mention these things? If not, that would explain
Not even mentioned: gibbons and humans share long achilles tendon and long lower back, opposite of extant great apes.
why Erika doesn't either.
*Human bipedalism* cannot be *explained* without it. (It can be discussed & lectured, but not explained.) Picking out a few unique features and ignoring others doesn't explain anything.
I acknowledge that chromosome 2 distinguishes extant humans from allH/P split estimated timing .9ma is much later than MSC (Medit. & Red Sea dried out); H erectus bridged the est. date, so would have had 24, not 23 like Hs. I doubt their estimate.There's also this: https://bmcgenomics.biomedcentral.com/articles/10.1186/s12864-022-08828-7Not sure what chromosome 2 fusion has to do with this topic. Please
elaborate.
other extant apes, and that the most parsimonious explanation is that
the fusion event happened after the LCA of humans and other extant
apes.
According to this:
<https://en.wikipedia.org/wiki/Hominini>
LCA of gibbons and humans existed around 15.7 mya.
LCA of orangs and humans existed around 8.8 mya.
LCA of gorillas and humans existed around 6.3 mya.
LCA of chimpanzees and humans existed some time after that, with no specified date. I have read other articles which suggest 4 mya.
So your cited paper's estimated date for the fusion event of 0.9 mya
is well after those dates. I agree that sounds very recent, but
either way doesn't inform when the human lineage first began
terrestrial bipedalism.
be precursor to both knuckle-walking and human terrestrial bipedalism.
On Sunday, October 30, 2022 at 2:40:46 AM UTC-4, 69jp...@gmail.com wrote:of other bipeds (T rex, giant short faced kangaroo, giant ground sloth, running jesus lizard). This primitive mechanical gyroscope was replaced by genetic software improvements enabling reduced body bone weight (esp. femur & occiput), faster & longer
On Sat, 29 Oct 2022 05:26:51 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Saturday, October 29, 2022 at 2:11:43 AM UTC-4, 69jp...@gmail.com wrote:
On Fri, 28 Oct 2022 21:26:43 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Friday, October 28, 2022 at 5:45:10 PM UTC-4, Daud Deden wrote:
On Friday, October 28, 2022 at 4:45:58 AM UTC-4, 69jp...@gmail.com wrote:
On Thu, 27 Oct 2022 21:53:46 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Friday, October 28, 2022 at 12:20:59 AM UTC-4, Daud Deden wrote:
On Friday, October 28, 2022 at 12:13:33 AM UTC-4, Daud Deden wrote:
On Thursday, October 27, 2022 at 10:56:53 PM UTC-4, 69jp...@gmail.com wrote:
On Thu, 27 Oct 2022 16:44:19 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Thursday, October 27, 2022 at 5:53:29 AM UTC-4, 69jp...@gmail.com wrote:
On Thu, 27 Oct 2022 02:17:42 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Wednesday, October 26, 2022 at 7:56:43 PM UTC-4, 69jp...@gmail.com wrote:
On Wed, 26 Oct 2022 03:17:08 -0700 (PDT), Daud Deden >> >> >> > >> > > >> >> <daud....@gmail.com> wrote:
On Wednesday, October 26, 2022 at 4:10:49 AM UTC-4, 69jp...@gmail.com wrote:
On Tue, 25 Oct 2022 16:32:06 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Tuesday, October 25, 2022 at 6:59:05 PM UTC-4, 69jp...@gmail.com wrote:
On Tue, 25 Oct 2022 01:18:27 -0700, Trolidan7Bigger butt bones, bigger brain bones, initially. >> >> >> > >> > > >> >> >> >Homo erectus had unusually thick dense femurs and unusually thick dense occiputs (rear skull bone), which counterbalanced the pace over orthogonal bipedal treks on the ground, substituting for the more typical long dense tail
<Trol...@eternal-september.org> wrote:
On 10/23/22 11:50 PM, jillery wrote:Watch the cited videos. Erika points out the challenges of going from
Gutsick Gibbon is the Youtube handle of a biological anthropology PhD
student named Erika. Two of her recent videos discuss some of the
latest developments relating to the origins of human bipedalism:
<https://www.youtube.com/watch?v=kbQAgPSHbZE> >> >> >> > >> > > >> >> >> >> >>
The above is a link to a 32-minute video where Erika discusses several
papers relating to Sahelanthropus tchadensis. This fossil is
remarkable in part because it's dated to about 7mya and was found in
central-african Chad, and also because it may be the oldest bipedal
hominin fossil found to date. However, there appears to be strong
disagreement whether the evidence supports bipedalism.
<https://www.youtube.com/watch?v=Nwkfkp360ps> >> >> >> > >> > > >> >> >> >> >>
The above is a link to a 22-minute video where Erika discusses several
hypotheses about *why* our ancestors shifted to obligate bipedalism.
She discusses several hypotheses, and presents compelling arguments
for her preferred one.
I tend to think of it as none of the above.
Simply because it is not that easy to stand upright.
When an animal stands upright you need to solve a problem -
how do you keep from falling over forward and backward.
This might seem simple but it is not because with a four
footed animal the center of gravity forward and backward
is between the front legs and the back legs, and often
that is a greater distance than between the left legs and
the right legs.
quadruped to biped, the differences between upright posture and
bipedalism, and the plausibility of suspensory orthograde posture in
trees as a precursor to bipedalism on the ground.
Some animals that sort of walk on twos have not solved theThat's why humans like big butts, I can not lie. >> >> >> > >> > > >> >> >> >
problem - a kangaroo can hop but in general it can not
stably stand. Either way, in essence, the long hand enables
force to be supplied to the far front and far back to counter
falling forward or backward - the forefoot and big toe are
the front force appliers and the heel is the back force
applier. Then of course there are some animals that might
sort of walk on threes (I am thinking of the Jerboa) - but
humans have an extra problem because they have no tail to
possibly act as an extra walking limb, or at least a balance.
suspensory slow brachiation x arboreal bipedalism, as in European miocene - pliocene apes and similar to but distinct from faster extant gibbons.S chadensis was imo not a habitual nor obligate terrestrial orthograde biped, nor a part-time knucklewalking terrestrial quadruped, its foramen magnum reflected a more primitive arboreal orthograde bipedalism associated with@378 cm^3, S. tchadensis' braincase is similar to that of extant
Casually walking while chewing gum, chatting and carrying a squirming child is something only humans could ever do.
chimpanzees and approximately a third the size of modern human brains.
of the foramen magnum.
Chimps & gorillas became more quadrupedal (partly pronograde terrestrial knucklewalking) while Homo became more bipedal (fully orthograde habitual obligate terrestrial striding), these produced changes of position and orientation
hominoid, hominin & Homo evolution, one which I have already specifically addressed earlier. She and the various authors seem to be unable to comprehend the significance of arboreal habitual bipedalism. The authors do not disagree with my opinion, theyI am so far sorely disappointed. At around 8:23, Erika intelligently but ignorantly describes the position of the foramen magnum and its significance. To her, bipedalism is terrestrial bipedalism. That is the central flaw in the study ofAfter a sneak peek, I see the paper, Postcranial ..., about the femur. I've skimmed it, no change in my thinking. But I'm flexible.Ok, I'd watched half of the 2nd video. I'll watch both tomorrow. I'll certainly learn something, I always do. For now, I stand behind every word I wrote earlier about Homo & Sahelanthropus.Once again, watch the cited video. Erika identifies the paper in theIf only there were some way to judge between contrasting opinions...They might be right.The authors of the paper Erika cited disagree with your opinion.
https://carta.anthropogeny.org/moca/topics/foramen-magnum-placement#:~:text=The%20foramen%20magnum%20position%20has,case%20for%20Ardipithecus%20and%20Sahelanthropus.
Parsimony is good.
Please direct me to the author(s) who disagree with what I wrote earlier. I don't know where to start, which vid, which paper... I'll examine inconsistencies (their or mine).
first few minutes of the first vdeo. But if you watch/listen to all
of both, you might actually learn something.
I can't find your quote in either video. Why don't you know where youBeen there, done that. I agree it suks.I acknowledge in the first video Erika mostly uses "bipedalism"My written response was lost. Damn. 15 sentences evaporated.
without distinction between arboreal and terrestrial. However, her >> >> >> > argument explicitly distinguishes between hominin and panin, and also
explicitly mentions terrestrial bipedality once. My understanding is
Erika uses hominin v panin to distinguish terrestrial v arboreal
bipedalism. I could be wrong.
Also, in the second video, Erika explicitly identifies arboreal
bipedalism as an enabling adaptation to terrestrial bipedalism. So to
say she doesn't comprehend its significance is an exaggeration at >> >> >> > least.
Erika is careful for copyright purposes to limit how much of the cited
paper she includes in her video, so I can't say if the paper's authors
make an explicit distinction between arboreal and terrestrial
bipedalism. Someone who has access to the full paper will have to >> >> >> > weigh in on that point.
However, Erika does mention that the paper discusses anatomical
features of the femur (proto linear aspira, gluteal tuberosity, calcar
femoral {sp?}), and cortical bone of the ulnae. My understanding is >> >> >> > these features are not present in arboreal bipedal species, and
instead indicate the more robust musculature of terrestrial
bipedalism.
Finally, Erika's expressed reservation with the paper is if the
evidence supports habitual bipedalism. She argues that would inform >> >> >> > whether the common ancestor between hominin and panin was more
human-like or more chimpanzee-like.
I can't find where Erika says that,The data graphs have nothing about hylobatids or macaques, so are worthless.
Near the end of video one, Erika talks about 'bipedal or arboreal', revealing that she still doesn't get it.
J: "these features are not present in arboreal bipedal species"
Possibly video 2.
got that quote?
The quote by Erica was "bipedal or arboreal" (or VV). It was referenced amongst the 15 vaporised sentences. I can't watch the videos again until I get to a computer, youtube burns cell phone data too quick. Monday.
I am hard-pressed to describe extant humans as arboreal bipeds.but I suspect she's referring to
the 4 anatomical features of the tibia [femur] and ulnae I mention above. What
arboreal bipedal species do you know with these features?
All, in a spectrum, Homo at one end, arboreals the other.
Probable part-time arboreal bipeds: Homo habilis, georgicus, naledi, florensis, etc.
Human
are likely descended from arboreal bipeds, but it's a derived
characteristic.
I acknowledge that chromosome 2 distinguishes extant humans from allExtant knucklewalking apes which sleep in bowl nests? Humans are gracile terrestrial bipeds.Do the cited papers mention these things? If not, that would explain
Not even mentioned: gibbons and humans share long achilles tendon and long lower back, opposite of extant great apes.
why Erika doesn't either.
*Human bipedalism* cannot be *explained* without it. (It can be discussed & lectured, but not explained.) Picking out a few unique features and ignoring others doesn't explain anything.
H/P split estimated timing .9ma is much later than MSC (Medit. & Red Sea dried out); H erectus bridged the est. date, so would have had 24, not 23 like Hs. I doubt their estimate.There's also this: https://bmcgenomics.biomedcentral.com/articles/10.1186/s12864-022-08828-7Not sure what chromosome 2 fusion has to do with this topic. Please
elaborate.
other extant apes, and that the most parsimonious explanation is that
the fusion event happened after the LCA of humans and other extant
apes.
Rather, during, imo.
According to this:
<https://en.wikipedia.org/wiki/Hominini>
LCA of gibbons and humans existed around 15.7 mya.
LCA of orangs and humans existed around 8.8 mya.
LCA of gorillas and humans existed around 6.3 mya.
LCA of chimpanzees and humans existed some time after that, with no
specified date. I have read other articles which suggest 4 mya.
So your cited paper's estimated date for the fusion event of 0.9 mya
is well after those dates. I agree that sounds very recent, but
either way doesn't inform when the human lineage first began
terrestrial bipedalism.
True.
As Erika points out, arboreal bipedalism can
be precursor to both knuckle-walking and human terrestrial bipedalism.
Yes, of course. Can & was, alongside arboreal bimanualism (slow brachiation).
On Tuesday, October 25, 2022 at 4:18:31 AM UTC-4, Trolidan7 wrote:
On 10/23/22 11:50 PM, jillery wrote:
Gutsick Gibbon is the Youtube handle of a biological anthropology PhD
student named Eriks. Two of her recent videos discuss some of the
latest developments relating to the origins of human bipedalism:
<https://www.youtube.com/watch?v=kbQAgPSHbZE>
The above is a link to a 32-minute video where Erika discusses several
papers relating to Sahelanthropus tchadensis. This fossil is
remarkable in part because it's dated to about 7mya and was found in
central-african Chad, and also because it may be the oldest bipedal
hominin fossil found to date. However, there appears to be strong
disagreement whether the evidence supports bipedalism.
<https://www.youtube.com/watch?v=Nwkfkp360ps>
The above is a link to a 22-minute video where Erika discusses several
hypotheses about *why* our ancestors shifted to obligate bipedalism.
She discusses several hypotheses, and presents compelling arguments
for her preferred one.
I tend to think of it as none of the above.
Did you watch the video, to see what they were?
Granted, with an open-ended subject like bipedalism, it is quite
unlikely that any "why" that we humans can easily formulate
gives a reason that is anywhere near complete. It's almost
as bad as theories about how we developed such amazingly
sophisticated speech. Simplified theories have been
given derisive names like "bow-wow theory" and "ding-dong theory"
or even been accused of being "pseudoscientific."
Simply because it is not that easy to stand upright.
When an animal stands upright you need to solve a problem -
how do you keep from falling over forward and backward.
This might seem simple but it is not because with a four
footed animal the center of gravity forward and backward
is between the front legs and the back legs, and often
that is a greater distance than between the left legs and
the right legs.
Some animals that sort of walk on twos have not solved the
problem - a kangaroo can hop but in general it can not
stably stand.
On the other hand, sifakas, the avahi, and the indri -- all lemurs -- are even more
obligate bipedal than we are: their forelimbs are even shorter
in proportion to their hindlimbs than ours are.
Their primary way of getting from one place to another
is fully bipedal hopping, generally between trees.
However, I have a book with a photograph
in which a sifaka has a very typically human style
running pose, with arms swinging in opposite
orientation to her wide-apart (from front to back) legs.
Either way, in essence, the long hand enables
force to be supplied >> to the far front and far back to counter
falling forward or backward - the forefoot and big toe are
the front force appliers and the heel is the back force
applier. Then of course there are some animals that might
sort of walk on threes (I am thinking of the Jerboa) - but
humans have an extra problem because they have no tail to
possibly act as an extra walking limb, or at least a balance.
Indris have almost lost their tails, but you've made me wonder
whether the long, narrow tail of that sifaka was an aid in
balancing, making that human-like stride possible.
Peter Nyikos
Professor, Dept. of Mathematics -- standard disclaimer--
Univ. of South Carolina at Columbia
http://people.math.sc.edu/nyikos
How about that! You, who seldom post here, actually did an on-topic OP.
This puts you ahead of John Harshman: in the almost dozen years
since I returned here, I don't recall him ever doing an on-topic OP to sci.bio.paleontology.
This despite the fact that he has probably done a few thousand posts
here in that time.
I do have a few recommendations. The optimal place to post information about homini is sci.anthropology.paleo. Not only are they the "specialty" of that ng,
it is more active, with more regulars than s.b.p. Best of all perhaps, Pandora
takes a very active part there, going into depth with one person after another.
Pandora occasionally posts to s.b.p. too, but the majority of her posts here are OP's.
They are almost invariably excellent and thought-provoking, but she seldom comments on the thoughts she has provoked, even when they are on-topic
in every sense of the word.
On Monday, October 24, 2022 at 2:50:22 AM UTC-4, 69jp...@gmail.com wrote:
Gutsick Gibbon is the Youtube handle of a biological anthropology PhD
student named Eriks. Two of her recent videos discuss some of the
latest developments relating to the origins of human bipedalism:
<https://www.youtube.com/watch?v=kbQAgPSHbZE>
The above is a link to a 32-minute video where Erika discusses several
papers relating to Sahelanthropus tchadensis.
I don't have enough time this evening to watch either this video or
the one you mention below. This being a science ng, it is very
appropriate to give the titles of these papers. Those of us who
are interested in research papers shouldn't have to sit through a video
to find out what they are.
This fossil is remarkable in part because it's dated to about 7mya and was found in
central-african Chad, and also because it may be the oldest bipedal
hominin fossil found to date. However, there appears to be strong
disagreement whether the evidence supports bipedalism.
<https://www.youtube.com/watch?v=Nwkfkp360ps>
The above is a link to a 22-minute video where Erika discusses several
hypotheses about *why* our ancestors shifted to obligate bipedalism.
She discusses several hypotheses, and presents compelling arguments
for her preferred one.
In science, hypotheses on such an open ended theme are seldom
compelling. Before you decide to post this to s.a.p., I strongly recommend that you state this preferred hypothesis; some people there may already
have heard of it (especially Pandora, who comes across as a professional
well past the age of earning the Ph.D.) and have formulated ideas about it.
Peter Nyikos
Professor, Dept. of Mathematics -- standard disclaimer--
University of South Carolina
http://people.math.sc.edu/nyikos
On Sun, 30 Oct 2022 00:42:50 -0700 (PDT), Daud Dedentail of other bipeds (T rex, giant short faced kangaroo, giant ground sloth, running jesus lizard). This primitive mechanical gyroscope was replaced by genetic software improvements enabling reduced body bone weight (esp. femur & occiput), faster &
<daud....@gmail.com> wrote:
On Sunday, October 30, 2022 at 2:40:46 AM UTC-4, 69jp...@gmail.com wrote: >> On Sat, 29 Oct 2022 05:26:51 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Saturday, October 29, 2022 at 2:11:43 AM UTC-4, 69jp...@gmail.com wrote:
On Fri, 28 Oct 2022 21:26:43 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Friday, October 28, 2022 at 5:45:10 PM UTC-4, Daud Deden wrote:
On Friday, October 28, 2022 at 4:45:58 AM UTC-4, 69jp...@gmail.com wrote:
On Thu, 27 Oct 2022 21:53:46 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Friday, October 28, 2022 at 12:20:59 AM UTC-4, Daud Deden wrote:
On Friday, October 28, 2022 at 12:13:33 AM UTC-4, Daud Deden wrote:
On Thursday, October 27, 2022 at 10:56:53 PM UTC-4, 69jp...@gmail.com wrote:
On Thu, 27 Oct 2022 16:44:19 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Thursday, October 27, 2022 at 5:53:29 AM UTC-4, 69jp...@gmail.com wrote:
On Thu, 27 Oct 2022 02:17:42 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Wednesday, October 26, 2022 at 7:56:43 PM UTC-4, 69jp...@gmail.com wrote:
On Wed, 26 Oct 2022 03:17:08 -0700 (PDT), Daud Deden >> >> >> > >> > > >> >> <daud....@gmail.com> wrote:
On Wednesday, October 26, 2022 at 4:10:49 AM UTC-4, 69jp...@gmail.com wrote:
On Tue, 25 Oct 2022 16:32:06 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Tuesday, October 25, 2022 at 6:59:05 PM UTC-4, 69jp...@gmail.com wrote:
On Tue, 25 Oct 2022 01:18:27 -0700, Trolidan7 >> >> >> > >> > > >> >> >> >> <Trol...@eternal-september.org> wrote:
On 10/23/22 11:50 PM, jillery wrote:Watch the cited videos. Erika points out the challenges of going from
Gutsick Gibbon is the Youtube handle of a biological anthropology PhD
student named Erika. Two of her recent videos discuss some of the
latest developments relating to the origins of human bipedalism:
<https://www.youtube.com/watch?v=kbQAgPSHbZE>
The above is a link to a 32-minute video where Erika discusses several
papers relating to Sahelanthropus tchadensis. This fossil is
remarkable in part because it's dated to about 7mya and was found in
central-african Chad, and also because it may be the oldest bipedal
hominin fossil found to date. However, there appears to be strong
disagreement whether the evidence supports bipedalism.
<https://www.youtube.com/watch?v=Nwkfkp360ps>
The above is a link to a 22-minute video where Erika discusses several
hypotheses about *why* our ancestors shifted to obligate bipedalism.
She discusses several hypotheses, and presents compelling arguments
for her preferred one.
I tend to think of it as none of the above. >> >> >> > >> > > >> >> >> >> >
Simply because it is not that easy to stand upright.
When an animal stands upright you need to solve a problem -
how do you keep from falling over forward and backward.
This might seem simple but it is not because with a four
footed animal the center of gravity forward and backward
is between the front legs and the back legs, and often
that is a greater distance than between the left legs and
the right legs.
quadruped to biped, the differences between upright posture and
bipedalism, and the plausibility of suspensory orthograde posture in
trees as a precursor to bipedalism on the ground.
Some animals that sort of walk on twos have not solved theThat's why humans like big butts, I can not lie.
problem - a kangaroo can hop but in general it can not
stably stand. Either way, in essence, the long hand enables
force to be supplied to the far front and far back to counter
falling forward or backward - the forefoot and big toe are
the front force appliers and the heel is the back force
applier. Then of course there are some animals that might
sort of walk on threes (I am thinking of the Jerboa) - but
humans have an extra problem because they have no tail to
possibly act as an extra walking limb, or at least a balance.
Bigger butt bones, bigger brain bones, initially.
Homo erectus had unusually thick dense femurs and unusually thick dense occiputs (rear skull bone), which counterbalanced the pace over orthogonal bipedal treks on the ground, substituting for the more typical long dense
suspensory slow brachiation x arboreal bipedalism, as in European miocene - pliocene apes and similar to but distinct from faster extant gibbons.S chadensis was imo not a habitual nor obligate terrestrial orthograde biped, nor a part-time knucklewalking terrestrial quadruped, its foramen magnum reflected a more primitive arboreal orthograde bipedalism associated with@378 cm^3, S. tchadensis' braincase is similar to that of extant
Casually walking while chewing gum, chatting and carrying a squirming child is something only humans could ever do.
chimpanzees and approximately a third the size of modern human brains.
orientation of the foramen magnum.
Chimps & gorillas became more quadrupedal (partly pronograde terrestrial knucklewalking) while Homo became more bipedal (fully orthograde habitual obligate terrestrial striding), these produced changes of position and
hominoid, hominin & Homo evolution, one which I have already specifically addressed earlier. She and the various authors seem to be unable to comprehend the significance of arboreal habitual bipedalism. The authors do not disagree with my opinion, theyI am so far sorely disappointed. At around 8:23, Erika intelligently but ignorantly describes the position of the foramen magnum and its significance. To her, bipedalism is terrestrial bipedalism. That is the central flaw in the study ofAfter a sneak peek, I see the paper, Postcranial ..., about the femur. I've skimmed it, no change in my thinking. But I'm flexible.Ok, I'd watched half of the 2nd video. I'll watch both tomorrow. I'll certainly learn something, I always do. For now, I stand behind every word I wrote earlier about Homo & Sahelanthropus.Once again, watch the cited video. Erika identifies the paper in theIf only there were some way to judge between contrasting opinions...They might be right.The authors of the paper Erika cited disagree with your opinion.
https://carta.anthropogeny.org/moca/topics/foramen-magnum-placement#:~:text=The%20foramen%20magnum%20position%20has,case%20for%20Ardipithecus%20and%20Sahelanthropus.
Parsimony is good.
Please direct me to the author(s) who disagree with what I wrote earlier. I don't know where to start, which vid, which paper... I'll examine inconsistencies (their or mine).
first few minutes of the first vdeo. But if you watch/listen to all
of both, you might actually learn something.
I'm often offgrid. Wifi when I can.I can't find your quote in either video. Why don't you know where youBeen there, done that. I agree it suks.I acknowledge in the first video Erika mostly uses "bipedalism" >> >> >> > without distinction between arboreal and terrestrial. However, herMy written response was lost. Damn. 15 sentences evaporated.
argument explicitly distinguishes between hominin and panin, and also
explicitly mentions terrestrial bipedality once. My understanding is
Erika uses hominin v panin to distinguish terrestrial v arboreal >> >> >> > bipedalism. I could be wrong.
Also, in the second video, Erika explicitly identifies arboreal >> >> >> > bipedalism as an enabling adaptation to terrestrial bipedalism. So to
say she doesn't comprehend its significance is an exaggeration at >> >> >> > least.
Erika is careful for copyright purposes to limit how much of the cited
paper she includes in her video, so I can't say if the paper's authors
make an explicit distinction between arboreal and terrestrial
bipedalism. Someone who has access to the full paper will have to >> >> >> > weigh in on that point.
However, Erika does mention that the paper discusses anatomical >> >> >> > features of the femur (proto linear aspira, gluteal tuberosity, calcar
femoral {sp?}), and cortical bone of the ulnae. My understanding is
these features are not present in arboreal bipedal species, and >> >> >> > instead indicate the more robust musculature of terrestrial
bipedalism.
Finally, Erika's expressed reservation with the paper is if the >> >> >> > evidence supports habitual bipedalism. She argues that would inform
whether the common ancestor between hominin and panin was more
human-like or more chimpanzee-like.
I can't find where Erika says that,The data graphs have nothing about hylobatids or macaques, so are worthless.
Near the end of video one, Erika talks about 'bipedal or arboreal', revealing that she still doesn't get it.
J: "these features are not present in arboreal bipedal species"
Possibly video 2.
got that quote?
The quote by Erica was "bipedal or arboreal" (or VV). It was referenced amongst the 15 vaporised sentences. I can't watch the videos again until I get to a computer, youtube burns cell phone data too quick. Monday.I agree that videos on cell phones can be a challenge. As a rule, I
try to piggyback on open WiFi while using a VPN.
Alternately, ignore the video and read the transcript. On my Android,Thanks, I didn't know about the transcript.
below the video is the video title. To the right is a down caret. Tap
on the caret brings up the video description which has a "show
transcript" window. Tap on the window brings up the transcript, which
is text searchable without burning too much data.
I acknowledge it's all much easier on a full screen. FWIW I didn'tWill dig.
find either quote in either video.
They are at the far end. Rainforest H&G do climb trees seeking seasonal foods, fruits, honey, nuts, and during war hide in tree nests, but otherwise are terrestrial. Neanderthals may have hunted from treestands. No Homo had a divergent hallux.I am hard-pressed to describe extant humans as arboreal bipeds.but I suspect she's referring to
the 4 anatomical features of the tibia [femur] and ulnae I mention above. What
arboreal bipedal species do you know with these features?
All, in a spectrum, Homo at one end, arboreals the other.
Probable part-time arboreal bipeds: Homo habilis, georgicus, naledi, florensis, etc.So you don't mean H.sapiens or H. neanderthalensis.
Uncertain, but I think there was causation. The chr 2 fusion also partly inverted the script, a rare thing; which I think produced speciation. No Homo is known to have 24/48 chromosomes.Human
are likely descended from arboreal bipeds, but it's a derived
characteristic.
I acknowledge that chromosome 2 distinguishes extant humans from allExtant knucklewalking apes which sleep in bowl nests? Humans are gracile terrestrial bipeds.Do the cited papers mention these things? If not, that would explain >> >> why Erika doesn't either.
Not even mentioned: gibbons and humans share long achilles tendon and long lower back, opposite of extant great apes.
*Human bipedalism* cannot be *explained* without it. (It can be discussed & lectured, but not explained.) Picking out a few unique features and ignoring others doesn't explain anything.
H/P split estimated timing .9ma is much later than MSC (Medit. & Red Sea dried out); H erectus bridged the est. date, so would have had 24, not 23 like Hs. I doubt their estimate.There's also this: https://bmcgenomics.biomedcentral.com/articles/10.1186/s12864-022-08828-7Not sure what chromosome 2 fusion has to do with this topic. Please
elaborate.
other extant apes, and that the most parsimonious explanation is that
the fusion event happened after the LCA of humans and other extant
apes.
Rather, during, imo.Of course it's possible the fusion event coincidentally happened
during LCA, but less likely and not necessary.
fusion wouldn't have caused any loss of genetic information or aI'll stick with my conjecture.
speciation event, at least not initially. So it's more likely to have happened somewhere between 4 mya and 0.9 mya.
According to this:
<https://en.wikipedia.org/wiki/Hominini>
LCA of gibbons and humans existed around 15.7 mya.
LCA of orangs and humans existed around 8.8 mya.
LCA of gorillas and humans existed around 6.3 mya.
LCA of chimpanzees and humans existed some time after that, with no
specified date. I have read other articles which suggest 4 mya.
So your cited paper's estimated date for the fusion event of 0.9 mya
is well after those dates. I agree that sounds very recent, but
either way doesn't inform when the human lineage first began
terrestrial bipedalism.
True.
As Erika points out, arboreal bipedalism can
be precursor to both knuckle-walking and human terrestrial bipedalism.
Yes, of course. Can & was, alongside arboreal bimanualism (slow brachiation).
On Sunday, October 30, 2022 at 10:46:43 AM UTC-4, 69jp...@gmail.com wrote:
They are at the far end. Rainforest H&G do climb trees seeking seasonal foods, fruits, honey, nuts, and during war hide in tree nests, but otherwise are terrestrial. Neanderthals may have hunted from treestands. No Homo had a divergent hallux.So you don't mean H.sapiens or H. neanderthalensis.I am hard-pressed to describe extant humans as arboreal bipeds.but I suspect she's referring to
the 4 anatomical features of the tibia [femur] and ulnae I mention above. What
arboreal bipedal species do you know with these features?
All, in a spectrum, Homo at one end, arboreals the other.
Probable part-time arboreal bipeds: Homo habilis, georgicus, naledi, florensis, etc.
I've seen many young men climb coconut palms in SEAsia w/o tools, just takes practice & thirst.
Uncertain, but I think there was causation. The chr 2 fusion also partly inverted the script, a rare thing; which I think produced speciation. No Homo is known to have 24/48 chromosomes.Of course it's possible the fusion event coincidentally happenedHuman
are likely descended from arboreal bipeds, but it's a derived
characteristic.
I acknowledge that chromosome 2 distinguishes extant humans from allExtant knucklewalking apes which sleep in bowl nests? Humans are gracile terrestrial bipeds.Do the cited papers mention these things? If not, that would explain >> >> >> why Erika doesn't either.
Not even mentioned: gibbons and humans share long achilles tendon and long lower back, opposite of extant great apes.
*Human bipedalism* cannot be *explained* without it. (It can be discussed & lectured, but not explained.) Picking out a few unique features and ignoring others doesn't explain anything.
H/P split estimated timing .9ma is much later than MSC (Medit. & Red Sea dried out); H erectus bridged the est. date, so would have had 24, not 23 like Hs. I doubt their estimate.There's also this: https://bmcgenomics.biomedcentral.com/articles/10.1186/s12864-022-08828-7Not sure what chromosome 2 fusion has to do with this topic. Please >> >> >> elaborate.
other extant apes, and that the most parsimonious explanation is that
the fusion event happened after the LCA of humans and other extant
apes.
Rather, during, imo.
during LCA, but less likely and not necessary.
The chromosome 2I'll stick with my conjecture.
fusion wouldn't have caused any loss of genetic information or a
speciation event, at least not initially. So it's more likely to have
happened somewhere between 4 mya and 0.9 mya.
According to this:
<https://en.wikipedia.org/wiki/Hominini>
LCA of gibbons and humans existed around 15.7 mya.
LCA of orangs and humans existed around 8.8 mya.
LCA of gorillas and humans existed around 6.3 mya.
LCA of chimpanzees and humans existed some time after that, with no
specified date. I have read other articles which suggest 4 mya.
So your cited paper's estimated date for the fusion event of 0.9 mya
is well after those dates. I agree that sounds very recent, but
either way doesn't inform when the human lineage first began
terrestrial bipedalism.
True.
As Erika points out, arboreal bipedalism canYes, of course. Can & was, alongside arboreal bimanualism (slow brachiation).
be precursor to both knuckle-walking and human terrestrial bipedalism. >> >
On Sun, 30 Oct 2022 09:52:58 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Sunday, October 30, 2022 at 10:46:43 AM UTC-4, 69jp...@gmail.com wrote: <snip uncommented text for brevity>I am hard-pressed to describe tree-climbing as arboreal bipedalism, especially the way those young men climb coconut palms.
They are at the far end. Rainforest H&G do climb trees seeking seasonal foods, fruits, honey, nuts, and during war hide in tree nests, but otherwise are terrestrial. Neanderthals may have hunted from treestands. No Homo had a divergent hallux.So you don't mean H.sapiens or H. neanderthalensis.I am hard-pressed to describe extant humans as arboreal bipeds.but I suspect she's referring to
the 4 anatomical features of the tibia [femur] and ulnae I mention above. What
arboreal bipedal species do you know with these features?
All, in a spectrum, Homo at one end, arboreals the other.
Probable part-time arboreal bipeds: Homo habilis, georgicus, naledi, florensis, etc.
I've seen many young men climb coconut palms in SEAsia w/o tools, just takes practice & thirst.
I acknowledge the fusion event inverted part of chromosome 2. However,Uncertain, but I think there was causation. The chr 2 fusion also partly inverted the script, a rare thing; which I think produced speciation. No Homo is known to have 24/48 chromosomes.Of course it's possible the fusion event coincidentally happenedHuman
are likely descended from arboreal bipeds, but it's a derived
characteristic.
I acknowledge that chromosome 2 distinguishes extant humans from all >> >> other extant apes, and that the most parsimonious explanation is that >> >> the fusion event happened after the LCA of humans and other extantExtant knucklewalking apes which sleep in bowl nests? Humans are gracile terrestrial bipeds.Do the cited papers mention these things? If not, that would explain
Not even mentioned: gibbons and humans share long achilles tendon and long lower back, opposite of extant great apes.
why Erika doesn't either.
*Human bipedalism* cannot be *explained* without it. (It can be discussed & lectured, but not explained.) Picking out a few unique features and ignoring others doesn't explain anything.
H/P split estimated timing .9ma is much later than MSC (Medit. & Red Sea dried out); H erectus bridged the est. date, so would have had 24, not 23 like Hs. I doubt their estimate.There's also this: https://bmcgenomics.biomedcentral.com/articles/10.1186/s12864-022-08828-7Not sure what chromosome 2 fusion has to do with this topic. Please >> >> >> elaborate.
apes.
Rather, during, imo.
during LCA, but less likely and not necessary.
that didn't alter how genes are transcribed.
misconception. For any given DNA sequence, there is a 5-prime end and
a 3-prime end. Transcription from DNA to mRNA always starts from the
5-prime end and ends at the 3-prime end:
<https://www.thoughtco.com/steps-of-transcription-from-dna-to-rna-603895>
Some molecular biology might help unstick you from your conjecture.The chromosome 2I'll stick with my conjecture.
fusion wouldn't have caused any loss of genetic information or a
speciation event, at least not initially. So it's more likely to have
happened somewhere between 4 mya and 0.9 mya.
According to this:
<https://en.wikipedia.org/wiki/Hominini>
LCA of gibbons and humans existed around 15.7 mya.
LCA of orangs and humans existed around 8.8 mya.
LCA of gorillas and humans existed around 6.3 mya.
LCA of chimpanzees and humans existed some time after that, with no
specified date. I have read other articles which suggest 4 mya.
So your cited paper's estimated date for the fusion event of 0.9 mya >> >> is well after those dates. I agree that sounds very recent, but
either way doesn't inform when the human lineage first began
terrestrial bipedalism.
True.
As Erika points out, arboreal bipedalism canYes, of course. Can & was, alongside arboreal bimanualism (slow brachiation).
be precursor to both knuckle-walking and human terrestrial bipedalism. >> >
On Sunday, October 30, 2022 at 5:17:46 PM UTC-4, 69jp...@gmail.com wrote:bipedalism. Tswa pygmies climb tall trees by using neighboring small trees to start up, then bridge over to horizontal branches which they then walk on, using hands in tension, feet in compression. Monkeys doing the same switch to quadrupedalism, hands
On Sun, 30 Oct 2022 09:52:58 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Sunday, October 30, 2022 at 10:46:43 AM UTC-4, 69jp...@gmail.com wrote: >> <snip uncommented text for brevity>I am hard-pressed to describe tree-climbing as arboreal bipedalism,
They are at the far end. Rainforest H&G do climb trees seeking seasonal foods, fruits, honey, nuts, and during war hide in tree nests, but otherwise are terrestrial. Neanderthals may have hunted from treestands. No Homo had a divergent hallux.So you don't mean H.sapiens or H. neanderthalensis.I am hard-pressed to describe extant humans as arboreal bipeds.but I suspect she's referring to
the 4 anatomical features of the tibia [femur] and ulnae I mention above. What
arboreal bipedal species do you know with these features?
All, in a spectrum, Homo at one end, arboreals the other.
Probable part-time arboreal bipeds: Homo habilis, georgicus, naledi, florensis, etc.
I've seen many young men climb coconut palms in SEAsia w/o tools, just takes practice & thirst.
especially the way those young men climb coconut palms.
I watched my buddy climb swiftly (for a human) up a coconut palm, using his hands in (bimanual) tension and feet in (bipedal) compression, at the top of the stem, he spun off and dropped a half dozen nuts, then climbed down. That is one form of arboreal
I acknowledge the fusion event inverted part of chromosome 2. However,Uncertain, but I think there was causation. The chr 2 fusion also partly inverted the script, a rare thing; which I think produced speciation. No Homo is known to have 24/48 chromosomes.Of course it's possible the fusion event coincidentally happenedHuman
are likely descended from arboreal bipeds, but it's a derived
characteristic.
I acknowledge that chromosome 2 distinguishes extant humans from all >> >> >> other extant apes, and that the most parsimonious explanation is that >> >> >> the fusion event happened after the LCA of humans and other extantExtant knucklewalking apes which sleep in bowl nests? Humans are gracile terrestrial bipeds.Do the cited papers mention these things? If not, that would explain
Not even mentioned: gibbons and humans share long achilles tendon and long lower back, opposite of extant great apes.
why Erika doesn't either.
*Human bipedalism* cannot be *explained* without it. (It can be discussed & lectured, but not explained.) Picking out a few unique features and ignoring others doesn't explain anything.
H/P split estimated timing .9ma is much later than MSC (Medit. & Red Sea dried out); H erectus bridged the est. date, so would have had 24, not 23 like Hs. I doubt their estimate.There's also this: https://bmcgenomics.biomedcentral.com/articles/10.1186/s12864-022-08828-7Not sure what chromosome 2 fusion has to do with this topic. Please
elaborate.
apes.
Rather, during, imo.
during LCA, but less likely and not necessary.
that didn't alter how genes are transcribed.
All great apes have 24, all humans have 23 pairs (except Downs syndrome etc.). >The method of transcription is irrelevant, the *result* is speciation, no known exception, a genetic firewall.
Like hylobatids, humans do not have 24 pairs of chromosomes, nor sleep in arboreal bowl nests, nor have short backs, nor short legs. Like hylobatids, we have relatively long legs, walk upright and use hands to grasp tensionally.
My conjecture stands.
By the way, the video transcripts are cringeworthy. Hard to believe they are processed by a company called Alphabet, google-youtube's parent company. I expected far better performance from them.
This is a common
misconception. For any given DNA sequence, there is a 5-prime end and
a 3-prime end. Transcription from DNA to mRNA always starts from the
5-prime end and ends at the 3-prime end:
<https://www.thoughtco.com/steps-of-transcription-from-dna-to-rna-603895>
Some molecular biology might help unstick you from your conjecture.The chromosome 2I'll stick with my conjecture.
fusion wouldn't have caused any loss of genetic information or a
speciation event, at least not initially. So it's more likely to have
happened somewhere between 4 mya and 0.9 mya.
According to this:
<https://en.wikipedia.org/wiki/Hominini>
LCA of gibbons and humans existed around 15.7 mya.
LCA of orangs and humans existed around 8.8 mya.
LCA of gorillas and humans existed around 6.3 mya.
LCA of chimpanzees and humans existed some time after that, with no >> >> >> specified date. I have read other articles which suggest 4 mya.
So your cited paper's estimated date for the fusion event of 0.9 mya >> >> >> is well after those dates. I agree that sounds very recent, but
either way doesn't inform when the human lineage first began
terrestrial bipedalism.
True.
As Erika points out, arboreal bipedalism can
be precursor to both knuckle-walking and human terrestrial bipedalism.
Yes, of course. Can & was, alongside arboreal bimanualism (slow brachiation).
On Sun, 30 Oct 2022 16:58:57 -0700 (PDT), Daud Dedenarboreal bipedalism. Tswa pygmies climb tall trees by using neighboring small trees to start up, then bridge over to horizontal branches which they then walk on, using hands in tension, feet in compression. Monkeys doing the same switch to quadrupedalism,
<daud....@gmail.com> wrote:
On Sunday, October 30, 2022 at 5:17:46 PM UTC-4, 69jp...@gmail.com wrote: >> On Sun, 30 Oct 2022 09:52:58 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Sunday, October 30, 2022 at 10:46:43 AM UTC-4, 69jp...@gmail.com wrote:<snip uncommented text for brevity>
I am hard-pressed to describe tree-climbing as arboreal bipedalism,They are at the far end. Rainforest H&G do climb trees seeking seasonal foods, fruits, honey, nuts, and during war hide in tree nests, but otherwise are terrestrial. Neanderthals may have hunted from treestands. No Homo had a divergent hallux.So you don't mean H.sapiens or H. neanderthalensis.I am hard-pressed to describe extant humans as arboreal bipeds.but I suspect she's referring to
the 4 anatomical features of the tibia [femur] and ulnae I mention above. What
arboreal bipedal species do you know with these features?
All, in a spectrum, Homo at one end, arboreals the other.
Probable part-time arboreal bipeds: Homo habilis, georgicus, naledi, florensis, etc.
I've seen many young men climb coconut palms in SEAsia w/o tools, just takes practice & thirst.
especially the way those young men climb coconut palms.
I watched my buddy climb swiftly (for a human) up a coconut palm, using his hands in (bimanual) tension and feet in (bipedal) compression, at the top of the stem, he spun off and dropped a half dozen nuts, then climbed down. That is one form of
And you yours.I acknowledge the fusion event inverted part of chromosome 2. However,Uncertain, but I think there was causation. The chr 2 fusion also partly inverted the script, a rare thing; which I think produced speciation. No Homo is known to have 24/48 chromosomes.Of course it's possible the fusion event coincidentally happenedHuman
are likely descended from arboreal bipeds, but it's a derived
characteristic.
I acknowledge that chromosome 2 distinguishes extant humans from allExtant knucklewalking apes which sleep in bowl nests? Humans are gracile terrestrial bipeds.Do the cited papers mention these things? If not, that would explain
Not even mentioned: gibbons and humans share long achilles tendon and long lower back, opposite of extant great apes.
why Erika doesn't either.
*Human bipedalism* cannot be *explained* without it. (It can be discussed & lectured, but not explained.) Picking out a few unique features and ignoring others doesn't explain anything.
H/P split estimated timing .9ma is much later than MSC (Medit. & Red Sea dried out); H erectus bridged the est. date, so would have had 24, not 23 like Hs. I doubt their estimate.There's also this: https://bmcgenomics.biomedcentral.com/articles/10.1186/s12864-022-08828-7Not sure what chromosome 2 fusion has to do with this topic. Please
elaborate.
other extant apes, and that the most parsimonious explanation is that
the fusion event happened after the LCA of humans and other extant >> >> >> apes.
Rather, during, imo.
during LCA, but less likely and not necessary.
that didn't alter how genes are transcribed.
All great apes have 24, all humans have 23 pairs (except Downs syndrome etc.).You're entitled to your opinion.
The method of transcription is irrelevant, the *result* is speciation, no known exception, a genetic firewall.
Like hylobatids, humans do not have 24 pairs of chromosomes, nor sleep in arboreal bowl nests, nor have short backs, nor short legs. Like hylobatids, we have relatively long legs, walk upright and use hands to grasp tensionally.
My conjecture stands.
By the way, the video transcripts are cringeworthy. Hard to believe they are processed by a company called Alphabet, google-youtube's parent company. I expected far better performance from them.
This is a common
misconception. For any given DNA sequence, there is a 5-prime end and
a 3-prime end. Transcription from DNA to mRNA always starts from the
5-prime end and ends at the 3-prime end:
<https://www.thoughtco.com/steps-of-transcription-from-dna-to-rna-603895> >> >> The chromosome 2
Some molecular biology might help unstick you from your conjecture.fusion wouldn't have caused any loss of genetic information or aI'll stick with my conjecture.
speciation event, at least not initially. So it's more likely to have >> >> happened somewhere between 4 mya and 0.9 mya.
According to this:
<https://en.wikipedia.org/wiki/Hominini>
LCA of gibbons and humans existed around 15.7 mya.
LCA of orangs and humans existed around 8.8 mya.
LCA of gorillas and humans existed around 6.3 mya.
LCA of chimpanzees and humans existed some time after that, with no >> >> >> specified date. I have read other articles which suggest 4 mya.
So your cited paper's estimated date for the fusion event of 0.9 mya
is well after those dates. I agree that sounds very recent, but
either way doesn't inform when the human lineage first began
terrestrial bipedalism.
True.
As Erika points out, arboreal bipedalism can
be precursor to both knuckle-walking and human terrestrial bipedalism.
Yes, of course. Can & was, alongside arboreal bimanualism (slow brachiation).
On Sunday, October 30, 2022 at 10:20:34 PM UTC-4, 69jp...@gmail.com wrote:arboreal bipedalism. Tswa pygmies climb tall trees by using neighboring small trees to start up, then bridge over to horizontal branches which they then walk on, using hands in tension, feet in compression. Monkeys doing the same switch to quadrupedalism,
On Sun, 30 Oct 2022 16:58:57 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Sunday, October 30, 2022 at 5:17:46 PM UTC-4, 69jp...@gmail.com wrote: >> >> On Sun, 30 Oct 2022 09:52:58 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Sunday, October 30, 2022 at 10:46:43 AM UTC-4, 69jp...@gmail.com wrote:<snip uncommented text for brevity>
I am hard-pressed to describe tree-climbing as arboreal bipedalism,They are at the far end. Rainforest H&G do climb trees seeking seasonal foods, fruits, honey, nuts, and during war hide in tree nests, but otherwise are terrestrial. Neanderthals may have hunted from treestands. No Homo had a divergent hallux.So you don't mean H.sapiens or H. neanderthalensis.I am hard-pressed to describe extant humans as arboreal bipeds.but I suspect she's referring to
the 4 anatomical features of the tibia [femur] and ulnae I mention above. What
arboreal bipedal species do you know with these features?
All, in a spectrum, Homo at one end, arboreals the other.
Probable part-time arboreal bipeds: Homo habilis, georgicus, naledi, florensis, etc.
I've seen many young men climb coconut palms in SEAsia w/o tools, just takes practice & thirst.
especially the way those young men climb coconut palms.
I watched my buddy climb swiftly (for a human) up a coconut palm, using his hands in (bimanual) tension and feet in (bipedal) compression, at the top of the stem, he spun off and dropped a half dozen nuts, then climbed down. That is one form of
And you yours.You're entitled to your opinion.
I acknowledge the fusion event inverted part of chromosome 2. However, >> >> that didn't alter how genes are transcribed.Uncertain, but I think there was causation. The chr 2 fusion also partly inverted the script, a rare thing; which I think produced speciation. No Homo is known to have 24/48 chromosomes.Of course it's possible the fusion event coincidentally happenedHuman
are likely descended from arboreal bipeds, but it's a derived
characteristic.
I acknowledge that chromosome 2 distinguishes extant humans from allExtant knucklewalking apes which sleep in bowl nests? Humans are gracile terrestrial bipeds.Do the cited papers mention these things? If not, that would explain
Not even mentioned: gibbons and humans share long achilles tendon and long lower back, opposite of extant great apes.
why Erika doesn't either.
*Human bipedalism* cannot be *explained* without it. (It can be discussed & lectured, but not explained.) Picking out a few unique features and ignoring others doesn't explain anything.
H/P split estimated timing .9ma is much later than MSC (Medit. & Red Sea dried out); H erectus bridged the est. date, so would have had 24, not 23 like Hs. I doubt their estimate.There's also this: https://bmcgenomics.biomedcentral.com/articles/10.1186/s12864-022-08828-7Not sure what chromosome 2 fusion has to do with this topic. Please
elaborate.
other extant apes, and that the most parsimonious explanation is that
the fusion event happened after the LCA of humans and other extant >> >> >> >> apes.
Rather, during, imo.
during LCA, but less likely and not necessary.
All great apes have 24, all humans have 23 pairs (except Downs syndrome etc.).
The method of transcription is irrelevant, the *result* is speciation, no known exception, a genetic firewall.
Like hylobatids, humans do not have 24 pairs of chromosomes, nor sleep in arboreal bowl nests, nor have short backs, nor short legs. Like hylobatids, we have relatively long legs, walk upright and use hands to grasp tensionally.
My conjecture stands.
By the way, the video transcripts are cringeworthy. Hard to believe they are processed by a company called Alphabet, google-youtube's parent company. I expected far better performance from them.
This is a common
misconception. For any given DNA sequence, there is a 5-prime end and
a 3-prime end. Transcription from DNA to mRNA always starts from the
5-prime end and ends at the 3-prime end:
<https://www.thoughtco.com/steps-of-transcription-from-dna-to-rna-603895>
Some molecular biology might help unstick you from your conjecture.The chromosome 2I'll stick with my conjecture.
fusion wouldn't have caused any loss of genetic information or a
speciation event, at least not initially. So it's more likely to have >> >> >> happened somewhere between 4 mya and 0.9 mya.
According to this:
<https://en.wikipedia.org/wiki/Hominini>
LCA of gibbons and humans existed around 15.7 mya.
LCA of orangs and humans existed around 8.8 mya.
LCA of gorillas and humans existed around 6.3 mya.
LCA of chimpanzees and humans existed some time after that, with no
specified date. I have read other articles which suggest 4 mya.
So your cited paper's estimated date for the fusion event of 0.9 mya
is well after those dates. I agree that sounds very recent, but
either way doesn't inform when the human lineage first began
terrestrial bipedalism.
True.
As Erika points out, arboreal bipedalism can
be precursor to both knuckle-walking and human terrestrial bipedalism.
Yes, of course. Can & was, alongside arboreal bimanualism (slow brachiation).
On Sun, 30 Oct 2022 21:59:15 -0700 (PDT), Daud Dedenarboreal bipedalism. Tswa pygmies climb tall trees by using neighboring small trees to start up, then bridge over to horizontal branches which they then walk on, using hands in tension, feet in compression. Monkeys doing the same switch to quadrupedalism,
<daud....@gmail.com> wrote:
On Sunday, October 30, 2022 at 10:20:34 PM UTC-4, 69jp...@gmail.com wrote: >> On Sun, 30 Oct 2022 16:58:57 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Sunday, October 30, 2022 at 5:17:46 PM UTC-4, 69jp...@gmail.com wrote:
On Sun, 30 Oct 2022 09:52:58 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Sunday, October 30, 2022 at 10:46:43 AM UTC-4, 69jp...@gmail.com wrote:<snip uncommented text for brevity>
I am hard-pressed to describe tree-climbing as arboreal bipedalism,They are at the far end. Rainforest H&G do climb trees seeking seasonal foods, fruits, honey, nuts, and during war hide in tree nests, but otherwise are terrestrial. Neanderthals may have hunted from treestands. No Homo had a divergent hallux.So you don't mean H.sapiens or H. neanderthalensis.Probable part-time arboreal bipeds: Homo habilis, georgicus, naledi, florensis, etc.I am hard-pressed to describe extant humans as arboreal bipeds. >> >> >> >but I suspect she's referring to
the 4 anatomical features of the tibia [femur] and ulnae I mention above. What
arboreal bipedal species do you know with these features?
All, in a spectrum, Homo at one end, arboreals the other.
I've seen many young men climb coconut palms in SEAsia w/o tools, just takes practice & thirst.
especially the way those young men climb coconut palms.
I watched my buddy climb swiftly (for a human) up a coconut palm, using his hands in (bimanual) tension and feet in (bipedal) compression, at the top of the stem, he spun off and dropped a half dozen nuts, then climbed down. That is one form of
Coincidence, perhaps.So that's something else we agree about.And you yours.You're entitled to your opinion.
I acknowledge the fusion event inverted part of chromosome 2. However, >> >> that didn't alter how genes are transcribed.Uncertain, but I think there was causation. The chr 2 fusion also partly inverted the script, a rare thing; which I think produced speciation. No Homo is known to have 24/48 chromosomes.Of course it's possible the fusion event coincidentally happenedHuman
are likely descended from arboreal bipeds, but it's a derived
characteristic.
I acknowledge that chromosome 2 distinguishes extant humans from allExtant knucklewalking apes which sleep in bowl nests? Humans are gracile terrestrial bipeds.Do the cited papers mention these things? If not, that would explain
Not even mentioned: gibbons and humans share long achilles tendon and long lower back, opposite of extant great apes.
why Erika doesn't either.
*Human bipedalism* cannot be *explained* without it. (It can be discussed & lectured, but not explained.) Picking out a few unique features and ignoring others doesn't explain anything.
H/P split estimated timing .9ma is much later than MSC (Medit. & Red Sea dried out); H erectus bridged the est. date, so would have had 24, not 23 like Hs. I doubt their estimate.There's also this: https://bmcgenomics.biomedcentral.com/articles/10.1186/s12864-022-08828-7Not sure what chromosome 2 fusion has to do with this topic. Please
elaborate.
other extant apes, and that the most parsimonious explanation is that
the fusion event happened after the LCA of humans and other extant
apes.
Rather, during, imo.
during LCA, but less likely and not necessary.
All great apes have 24, all humans have 23 pairs (except Downs syndrome etc.).
The method of transcription is irrelevant, the *result* is speciation, no known exception, a genetic firewall.
Like hylobatids, humans do not have 24 pairs of chromosomes, nor sleep in arboreal bowl nests, nor have short backs, nor short legs. Like hylobatids, we have relatively long legs, walk upright and use hands to grasp tensionally.
My conjecture stands.
By the way, the video transcripts are cringeworthy. Hard to believe they are processed by a company called Alphabet, google-youtube's parent company. I expected far better performance from them.
This is a common
misconception. For any given DNA sequence, there is a 5-prime end and >> >> a 3-prime end. Transcription from DNA to mRNA always starts from the >> >> 5-prime end and ends at the 3-prime end:
<https://www.thoughtco.com/steps-of-transcription-from-dna-to-rna-603895>
Some molecular biology might help unstick you from your conjecture.The chromosome 2I'll stick with my conjecture.
fusion wouldn't have caused any loss of genetic information or a
speciation event, at least not initially. So it's more likely to have
happened somewhere between 4 mya and 0.9 mya.
According to this:
<https://en.wikipedia.org/wiki/Hominini>
LCA of gibbons and humans existed around 15.7 mya.
LCA of orangs and humans existed around 8.8 mya.
LCA of gorillas and humans existed around 6.3 mya.
LCA of chimpanzees and humans existed some time after that, with no
specified date. I have read other articles which suggest 4 mya. >> >> >> >>
So your cited paper's estimated date for the fusion event of 0.9 mya
is well after those dates. I agree that sounds very recent, but >> >> >> >> either way doesn't inform when the human lineage first began
terrestrial bipedalism.
True.
As Erika points out, arboreal bipedalism can
be precursor to both knuckle-walking and human terrestrial bipedalism.
Yes, of course. Can & was, alongside arboreal bimanualism (slow brachiation).
Gutsick Gibbon is the Youtube handle of a biological anthropology PhD-
student named Eriks. Two of her recent videos discuss some of the
latest developments relating to the origins of human bipedalism:
<https://www.youtube.com/watch?v=kbQAgPSHbZE>
The above is a link to a 32-minute video where Erika discusses several
papers relating to Sahelanthropus tchadensis. This fossil is
remarkable in part because it's dated to about 7mya and was found in central-african Chad, and also because it may be the oldest bipedal
hominin fossil found to date. However, there appears to be strong disagreement whether the evidence supports bipedalism.
<https://www.youtube.com/watch?v=Nwkfkp360ps>
The above is a link to a 22-minute video where Erika discusses several hypotheses about *why* our ancestors shifted to obligate bipedalism.
She discusses several hypotheses, and presents compelling arguments
for her preferred one.
On 10/27/22 7:26 PM, Peter Nyikos wrote:
On Tuesday, October 25, 2022 at 4:18:31 AM UTC-4, Trolidan7 wrote:
On 10/23/22 11:50 PM, jillery wrote:
Gutsick Gibbon is the Youtube handle of a biological anthropology PhD
student named Eriks. Two of her recent videos discuss some of the
latest developments relating to the origins of human bipedalism:
<https://www.youtube.com/watch?v=kbQAgPSHbZE>
The above is a link to a 32-minute video where Erika discusses several >>> papers relating to Sahelanthropus tchadensis. This fossil is
remarkable in part because it's dated to about 7mya and was found in
central-african Chad, and also because it may be the oldest bipedal
hominin fossil found to date. However, there appears to be strong
disagreement whether the evidence supports bipedalism.
<https://www.youtube.com/watch?v=Nwkfkp360ps>
The above is a link to a 22-minute video where Erika discusses several >>> hypotheses about *why* our ancestors shifted to obligate bipedalism.
She discusses several hypotheses, and presents compelling arguments
for her preferred one.
I tend to think of it as none of the above.
Did you watch the video, to see what they were?
I did watch nearly all of both.
In general she studied questions about the nature
of the environmental factors that may have produced
bipedalism rather than the factors involving the
specific dynamics of walking.
I once partially remember a teacher a long time
ago saying science does not ask 'why' questions.
I argued that one could rephrase questions so
that they were essentially the same either using
or not using the word 'why'.
Reasonably, if
the question is short enough it can have an array
of meanings and what is referred to can be unclear.
This was about 30 years ago and it would take a while
to remember which specific class or subject.
About 'blood and lymph' and the nature of where
copper is on a cellular and extracellular level
in invertebrates and giving a reference I am also
sorry. It could take an incredible amount of digging
to find where and when I read that and I could still
be off when it comes to precisely when or where I
might have done that. I could be way off.
For the video I did that a few days ago.
Granted, with an open-ended subject like bipedalism, it is quite
unlikely that any "why" that we humans can easily formulate
gives a reason that is anywhere near complete.
It's almost as bad as theories about how we developed such amazingly sophisticated speech. Simplified theories have been
given derisive names like "bow-wow theory" and "ding-dong theory"
or even been accused of being "pseudoscientific."
Simply because it is not that easy to stand upright.
When an animal stands upright you need to solve a problem -
how do you keep from falling over forward and backward.
This might seem simple but it is not because with a four
footed animal the center of gravity forward and backward
is between the front legs and the back legs, and often
that is a greater distance than between the left legs and
the right legs.
Some animals that sort of walk on twos have not solved the
problem - a kangaroo can hop but in general it can not
stably stand.
On the other hand, sifakas, the avahi, and the indri -- all lemurs -- are even more
obligate bipedal than we are: their forelimbs are even shorter
in proportion to their hindlimbs than ours are.
Their primary way of getting from one place to another
is fully bipedal hopping, generally between trees.
However, I have a book with a photograph
in which a sifaka has a very typically human style
running pose, with arms swinging in opposite
orientation to her wide-apart (from front to back) legs.
She gave the idea that the apes may have once been
more bipedal, and then specialized for four legged
walking in chimps and gorillas and specialized for
bipedal walking in humans, and she did not specify
precisely what she was referring to. What you
are typing, however, may have parallels in natural
history that are what she is referring to.
Often the word 'walking' tends to imply locomotion
on the ground, but when you are climbing up, down,
or across a tree it can in some ways be motion
across a different substrate, just as 'swimming',
'walking', are 'flying' can often be thought of
as different things, involving substrates of liquid,
a solid ground, or air.
Are we obligate bipeds? For humans, it is possible
to crawl but that is rare. That tends to be most
commonly used. Do many apes or monkeys have four
'hands'? Often we tend to use the word 'hand' for
a limb that tends to manipulate objects, and 'wing'
for one that tends to fly. But if an animal is
moving by transferring to different locations on
or between trees, then the boundary between 'moving'
and 'manipulating objects' may be blurred.
It was several days ago, and I would have to rewatch
it again to summarize the different theories that
she gave and the specific one that she supported.
Admittedly, it was generally a different question.
Either way, in essence, the long hand enables
force to be supplied >> to the far front and far back to counter
falling forward or backward - the forefoot and big toe are
the front force appliers and the heel is the back force
applier. Then of course there are some animals that might
sort of walk on threes (I am thinking of the Jerboa) - but
humans have an extra problem because they have no tail to
possibly act as an extra walking limb, or at least a balance.
Indris have almost lost their tails, but you've made me wonder
whether the long, narrow tail of that sifaka was an aid in
balancing, making that human-like stride possible.
On Monday, October 24, 2022 at 2:50:22 AM UTC-4, 69jp...@gmail.com wrote:
Gutsick Gibbon is the Youtube handle of a biological anthropology PhD-
student named Eriks. Two of her recent videos discuss some of the
latest developments relating to the origins of human bipedalism:
<https://www.youtube.com/watch?v=kbQAgPSHbZE>
The above is a link to a 32-minute video where Erika discusses several
papers relating to Sahelanthropus tchadensis. This fossil is
remarkable in part because it's dated to about 7mya and was found in
central-african Chad, and also because it may be the oldest bipedal
hominin fossil found to date. However, there appears to be strong
disagreement whether the evidence supports bipedalism.
<https://www.youtube.com/watch?v=Nwkfkp360ps>
The above is a link to a 22-minute video where Erika discusses several
hypotheses about *why* our ancestors shifted to obligate bipedalism.
She discusses several hypotheses, and presents compelling arguments
for her preferred one.
Video by Erika on Lucy bipedalism: https://youtu.be/jo2ZLnucuHY
At 3:40 she talks about different modes of arboreal locomotion...she mentions "generalized miocene ape" & similar to "palmigrade pronograde arboreal quadrupeds of the miocene'.
To me, the European miocene apes were arboreal slow bimanual brachiating & slow upright bipedal walking on horizontal tree branches.
Is she referring to African miocene apes being pronograde palmigrade?
At 7:20, she apparently claims that chimp and gorilla arboreal traits interfere with their terrestrial locomotion "act to negate bipedalism" No, sleeping in bowl nests did that, selecting for short legs & backs.
https://youtu.be/jo2ZLnucuHY?t=451
I wanted to go in depth on this video, but there is a massive noisy halloween celebration of trick or treating goblins and princesses here at the library. So enough.
On Mon, 31 Oct 2022 15:15:01 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Monday, October 24, 2022 at 2:50:22 AM UTC-4, 69jp...@gmail.com wrote:Thank you for citing the above video. It's prelude to the ones I
Gutsick Gibbon is the Youtube handle of a biological anthropology PhD-
student named Eriks. Two of her recent videos discuss some of the
latest developments relating to the origins of human bipedalism:
<https://www.youtube.com/watch?v=kbQAgPSHbZE>
The above is a link to a 32-minute video where Erika discusses several
papers relating to Sahelanthropus tchadensis. This fossil is
remarkable in part because it's dated to about 7mya and was found in
central-african Chad, and also because it may be the oldest bipedal
hominin fossil found to date. However, there appears to be strong
disagreement whether the evidence supports bipedalism.
<https://www.youtube.com/watch?v=Nwkfkp360ps>
The above is a link to a 22-minute video where Erika discusses several
hypotheses about *why* our ancestors shifted to obligate bipedalism.
She discusses several hypotheses, and presents compelling arguments
for her preferred one.
Video by Erika on Lucy bipedalism: https://youtu.be/jo2ZLnucuHY
cited, and refers to them, and so complete a logical trilogy.
At 3:40 she talks about different modes of arboreal locomotion...she mentions "generalized miocene ape" & similar to "palmigrade pronograde arboreal quadrupeds of the miocene'.Erika says this:
To me, the European miocene apes were arboreal slow bimanual brachiating & slow upright bipedal walking on horizontal tree branches.
Is she referring to African miocene apes being pronograde palmigrade?
*********************************
Obviously australopithecus afarensis didn't evolve from a chimp but
from sort of generalized Miocene ape. But that being said, the
morphology of modern chimpanzees is at least similar to some of our palmigrade pronograde arboreal quadrupeds of the Miocene. *********************************
So yes, Erika is saying at least some African Miocene apes were
palmigrade aka foot parallel to the ground pronograde aka spine
parallel to the ground, similar to modern chimpanzees.
I don't know enough about Miocene apes to say if European and African
apes were different. My understanding is climate change caused
European Miocene apes to go extinct before Australopiths evolved in
Africa, which suggests to me the two environments were different
enough to support the differences you describe.
At 7:20, she apparently claims that chimp and gorilla arboreal traits interfere with their terrestrial locomotion "act to negate bipedalism" No, sleeping in bowl nests did that, selecting for short legs & backs.Erika says this:
https://youtu.be/jo2ZLnucuHY?t=451
***********************************************
Either way, the aspects that allow for arboriality found in
australopithecus afarensis are not the same types as the ones that we
find in chimpanzees and gorillas. In the latter two species, the
arboreal aspects act to negate efficient bipedality, whereas in australopithecus afarensis they're sort of removed from it. They
allow for arboreal behaviors when necessary but don't
harm the effectiveness of bipedality when the animal came down to the
ground.
*********************************************
Erika doesn't argue the cause for these arboreal aspects, but only
that their presence in chimpanzees and gorillas inhibits efficient bipedality. Anybody who has seen videos of gorillas and chimpanzees
walking bipedally would agree they are much less efficient at it than
are humans. Erika's point in paraphrase is that Lucy had a big butt, I
cannot lie, and so walked more like humans do.
I wanted to go in depth on this video, but there is a massive noisy halloween celebration of trick or treating goblins and princesses here at the library. So enough.I hope you find time once the ghosts and goblins have gone.
On Mon, 31 Oct 2022 15:15:01 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Monday, October 24, 2022 at 2:50:22 AM UTC-4, 69jp...@gmail.com wrote: >> Gutsick Gibbon is the Youtube handle of a biological anthropology PhDThank you for citing the above video. It's prelude to the ones I
student named Eriks. Two of her recent videos discuss some of the-
latest developments relating to the origins of human bipedalism:
<https://www.youtube.com/watch?v=kbQAgPSHbZE>
The above is a link to a 32-minute video where Erika discusses several
papers relating to Sahelanthropus tchadensis. This fossil is
remarkable in part because it's dated to about 7mya and was found in
central-african Chad, and also because it may be the oldest bipedal
hominin fossil found to date. However, there appears to be strong
disagreement whether the evidence supports bipedalism.
<https://www.youtube.com/watch?v=Nwkfkp360ps>
The above is a link to a 22-minute video where Erika discusses several
hypotheses about *why* our ancestors shifted to obligate bipedalism.
She discusses several hypotheses, and presents compelling arguments
for her preferred one.
Video by Erika on Lucy bipedalism: https://youtu.be/jo2ZLnucuHY
cited, and refers to them, and so complete a logical trilogy.
At 3:40 she talks about different modes of arboreal locomotion...she mentions "generalized miocene ape" & similar to "palmigrade pronograde arboreal quadrupeds of the miocene'.Erika says this:
To me, the European miocene apes were arboreal slow bimanual brachiating & slow upright bipedal walking on horizontal tree branches.
Is she referring to African miocene apes being pronograde palmigrade?
*********************************
Obviously australopithecus afarensis didn't evolve from a chimp but
from sort of generalized Miocene ape. But that being said, the
morphology of modern chimpanzees is at least similar to some of our palmigrade pronograde arboreal quadrupeds of the Miocene. *********************************
So yes, Erika is saying at least some African Miocene apes were
palmigrade aka foot parallel to the ground pronograde aka spine
parallel to the ground, similar to modern chimpanzees.
I don't know enough about Miocene apes to say if European and African
apes were different. My understanding is climate change caused
European Miocene apes to go extinct before Australopiths evolved in
Africa, which suggests to me the two environments were different
enough to support the differences you describe.
At 7:20, she apparently claims that chimp and gorilla arboreal traits interfere with their terrestrial locomotion "act to negate bipedalism" No, sleeping in bowl nests did that, selecting for short legs & backs.
https://youtu.be/jo2ZLnucuHY?t=451Erika says this:
***********************************************
Either way, the aspects that allow for arboriality found in
australopithecus afarensis are not the same types as the ones that we
find in chimpanzees and gorillas. In the latter two species, the
arboreal aspects
australopithecus afarensis they're sort of removed from it.
allow for arboreal behaviors when necessary but don't
harm the effectiveness of bipedality when the animal came down to the ground.
*********************************************
Erika doesn't argue the cause for these arboreal aspects, but only
that their presence in chimpanzees and gorillas inhibits efficient bipedality. Anybody who has seen videos of gorillas and chimpanzees
walking bipedally would agree they are much less efficient at it than
are humans. Erika's point in paraphrase is that Lucy had a big butt, I cannot lie, and so walked more like humans do.
I wanted to go in depth on this video, but there is a massive noisy halloween celebration of trick or treating goblins and princesses here at the library. So enough.I hope you find time once the ghosts and goblins have gone.
On Tuesday, November 1, 2022 at 4:17:31 AM UTC-4, 69jp...@gmail.com wrote:
On Mon, 31 Oct 2022 15:15:01 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
In another video, Top 3 Misconceptions about human evolution, she says that Sahelanthropus was the LCA of Homo / Pan, (though probably just in the general sense). https://www.youtube.com/watch?v=g4FTbZLkpzU&t=7sOn Monday, October 24, 2022 at 2:50:22 AM UTC-4, 69jp...@gmail.com wrote: >> Gutsick Gibbon is the Youtube handle of a biological anthropology PhD >> student named Eriks. Two of her recent videos discuss some of theThank you for citing the above video. It's prelude to the ones I
latest developments relating to the origins of human bipedalism:-
<https://www.youtube.com/watch?v=kbQAgPSHbZE>
The above is a link to a 32-minute video where Erika discusses several >> papers relating to Sahelanthropus tchadensis. This fossil is
remarkable in part because it's dated to about 7mya and was found in
central-african Chad, and also because it may be the oldest bipedal
hominin fossil found to date. However, there appears to be strong
disagreement whether the evidence supports bipedalism.
<https://www.youtube.com/watch?v=Nwkfkp360ps>
The above is a link to a 22-minute video where Erika discusses several >> hypotheses about *why* our ancestors shifted to obligate bipedalism.
She discusses several hypotheses, and presents compelling arguments
for her preferred one.
Video by Erika on Lucy bipedalism: https://youtu.be/jo2ZLnucuHY
cited, and refers to them, and so complete a logical trilogy.
In my view, Sahelanthropus is just a southwestern European Miocene ape, very similar to their eastern and northern kin. I see nothing palmigrade in any Miocene ape.
different from palmigrady.At 3:40 she talks about different modes of arboreal locomotion...she mentions "generalized miocene ape" & similar to "palmigrade pronograde arboreal quadrupeds of the miocene'.*********************************
To me, the European miocene apes were arboreal slow bimanual brachiating & slow upright bipedal walking on horizontal tree branches.
Is she referring to African miocene apes being pronograde palmigrade? Erika says this:
Obviously australopithecus afarensis didn't evolve from a chimp but
from sort of generalized Miocene ape. But that being said, the
morphology of modern chimpanzees is at least similar to some of our palmigrade pronograde arboreal quadrupeds of the Miocene. *********************************
So yes, Erika is saying at least some African Miocene apes wereChimps aren't palmigrade, no extant ape is, all monkeys are obligatory palmigrade. Humans are palmigrade only during infancy while knee-crawling and bear-walking (I'd guess only within a dome shelter). Humans and chimps hold tools in hands, but that's
palmigrade aka foot parallel to the ground pronograde aka spine
parallel to the ground, similar to modern chimpanzees.
cerebrum) and wide hips (Venus figurines?) and with Homo sapiens (software replaced mechanistic balancing, except in Khoisan and Andamaner females with very posterior buttocks (steatopygia), selected by long distance trekking.I don't know enough about Miocene apes to say if European and AfricanI opine that European Miocene apes expanded from the Black Sea region after the MSC, some of their descendants included australopiths, Homo etc. entering Africa in waves.
apes were different. My understanding is climate change caused
European Miocene apes to go extinct before Australopiths evolved in Africa, which suggests to me the two environments were different
enough to support the differences you describe.
At 7:20, she apparently claims that chimp and gorilla arboreal traits interfere with their terrestrial locomotion "act to negate bipedalism" No, sleeping in bowl nests did that, selecting for short legs & backs.I guess 'aspect' could include arboreal bowl nesting, I thought she meant arboreal locomotion only.
https://youtu.be/jo2ZLnucuHY?t=451Erika says this:
***********************************************
Either way, the aspects that allow for arboriality found in australopithecus afarensis are not the same types as the ones that we
find in chimpanzees and gorillas. In the latter two species, the
arboreal aspects
act to negate efficient bipedality,
Not arboreal hylobatids. Bowl sleeping in great apes shrank their leg, achilles & back length.
whereas in
australopithecus afarensis they're sort of removed from it.The key is whether australopiths & kin had halluces that could swivel outwardly while branch-walking and swivel inwardly while ground-walking.
They
allow for arboreal behaviors when necessary but don't
harm the effectiveness of bipedality when the animal came down to the ground.
*********************************************
Erika doesn't argue the cause for these arboreal aspects, but onlyConsider my earlier point about Homo erectus: thick heavy femur and skull occiput mechanically improved balance and pace while ground-walking orthogonally; this continued with neanderthals with pronounced occipital bun (bone + enlarged posteriorly
that their presence in chimpanzees and gorillas inhibits efficient bipedality. Anybody who has seen videos of gorillas and chimpanzees walking bipedally would agree they are much less efficient at it than
are humans. Erika's point in paraphrase is that Lucy had a big butt, I cannot lie, and so walked more like humans do.
I wanted to go in depth on this video, but there is a massive noisy halloween celebration of trick or treating goblins and princesses here at the library. So enough.I hope you find time once the ghosts and goblins have gone.
On Thursday, November 3, 2022 at 10:56:06 AM UTC-4, Daud Deden wrote:At 6:20 Erika claims Miocene apes didn't knucklewalk (since their hands were more like humans than chimps), then she claims they were "pronograde palmigrade like most monkeys do today", that is false, they occasionally ground walked bipedally slowly on
On Tuesday, November 1, 2022 at 4:17:31 AM UTC-4, 69jp...@gmail.com wrote:
On Mon, 31 Oct 2022 15:15:01 -0700 (PDT), Daud Deden <daud....@gmail.com> wrote:
Sahelanthropus has a flatter skull than modern chimps & humans. Chimps have a more prognathic muzzle, due to knucklewalking pronograde, derived from an ancestor with orthognathic muzzle. Chimp infant muzzles are more humanlike, more like sahelanthropus.In another video, Top 3 Misconceptions about human evolution, she says that Sahelanthropus was the LCA of Homo / Pan, (though probably just in the general sense). https://www.youtube.com/watch?v=g4FTbZLkpzU&t=7sOn Monday, October 24, 2022 at 2:50:22 AM UTC-4, 69jp...@gmail.com wrote:Thank you for citing the above video. It's prelude to the ones I
Gutsick Gibbon is the Youtube handle of a biological anthropology PhD >> student named Eriks. Two of her recent videos discuss some of the-
latest developments relating to the origins of human bipedalism:
<https://www.youtube.com/watch?v=kbQAgPSHbZE>
The above is a link to a 32-minute video where Erika discusses several
papers relating to Sahelanthropus tchadensis. This fossil is
remarkable in part because it's dated to about 7mya and was found in >> central-african Chad, and also because it may be the oldest bipedal >> hominin fossil found to date. However, there appears to be strong
disagreement whether the evidence supports bipedalism.
<https://www.youtube.com/watch?v=Nwkfkp360ps>
The above is a link to a 22-minute video where Erika discusses several
hypotheses about *why* our ancestors shifted to obligate bipedalism. >> She discusses several hypotheses, and presents compelling arguments >> for her preferred one.
Video by Erika on Lucy bipedalism: https://youtu.be/jo2ZLnucuHY
cited, and refers to them, and so complete a logical trilogy.
In my view, Sahelanthropus is just a southwestern European Miocene ape, very similar to their eastern and northern kin. I see nothing palmigrade in any Miocene ape.
s different from palmigrady.At 3:40 she talks about different modes of arboreal locomotion...she mentions "generalized miocene ape" & similar to "palmigrade pronograde arboreal quadrupeds of the miocene'.*********************************
To me, the European miocene apes were arboreal slow bimanual brachiating & slow upright bipedal walking on horizontal tree branches.
Is she referring to African miocene apes being pronograde palmigrade? Erika says this:
Obviously australopithecus afarensis didn't evolve from a chimp but
from sort of generalized Miocene ape. But that being said, the morphology of modern chimpanzees is at least similar to some of our palmigrade pronograde arboreal quadrupeds of the Miocene. *********************************
So yes, Erika is saying at least some African Miocene apes were palmigrade aka foot parallel to the ground pronograde aka spineChimps aren't palmigrade, no extant ape is, all monkeys are obligatory palmigrade. Humans are palmigrade only during infancy while knee-crawling and bear-walking (I'd guess only within a dome shelter). Humans and chimps hold tools in hands, but that'
parallel to the ground, similar to modern chimpanzees.
cerebrum) and wide hips (Venus figurines?) and with Homo sapiens (software replaced mechanistic balancing, except in Khoisan and Andamaner females with very posterior buttocks (steatopygia), selected by long distance trekking.I don't know enough about Miocene apes to say if European and African apes were different. My understanding is climate change causedI opine that European Miocene apes expanded from the Black Sea region after the MSC, some of their descendants included australopiths, Homo etc. entering Africa in waves.
European Miocene apes to go extinct before Australopiths evolved in Africa, which suggests to me the two environments were different
enough to support the differences you describe.
At 7:20, she apparently claims that chimp and gorilla arboreal traits interfere with their terrestrial locomotion "act to negate bipedalism" No, sleeping in bowl nests did that, selecting for short legs & backs.I guess 'aspect' could include arboreal bowl nesting, I thought she meant arboreal locomotion only.
https://youtu.be/jo2ZLnucuHY?t=451Erika says this:
***********************************************
Either way, the aspects that allow for arboriality found in australopithecus afarensis are not the same types as the ones that we find in chimpanzees and gorillas. In the latter two species, the arboreal aspects
act to negate efficient bipedality,
Not arboreal hylobatids. Bowl sleeping in great apes shrank their leg, achilles & back length.
whereas in
australopithecus afarensis they're sort of removed from it.The key is whether australopiths & kin had halluces that could swivel outwardly while branch-walking and swivel inwardly while ground-walking.
They
allow for arboreal behaviors when necessary but don't
harm the effectiveness of bipedality when the animal came down to the ground.
*********************************************
Erika doesn't argue the cause for these arboreal aspects, but onlyConsider my earlier point about Homo erectus: thick heavy femur and skull occiput mechanically improved balance and pace while ground-walking orthogonally; this continued with neanderthals with pronounced occipital bun (bone + enlarged posteriorly
that their presence in chimpanzees and gorillas inhibits efficient bipedality. Anybody who has seen videos of gorillas and chimpanzees walking bipedally would agree they are much less efficient at it than are humans. Erika's point in paraphrase is that Lucy had a big butt, I cannot lie, and so walked more like humans do.
I wanted to go in depth on this video, but there is a massive noisy halloween celebration of trick or treating goblins and princesses here at the library. So enough.I hope you find time once the ghosts and goblins have gone.
On Tuesday, November 1, 2022 at 4:17:31 AM UTC-4, 69jp...@gmail.com wrote:
On Mon, 31 Oct 2022 15:15:01 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Monday, October 24, 2022 at 2:50:22 AM UTC-4, 69jp...@gmail.com wrote: >> >> Gutsick Gibbon is the Youtube handle of a biological anthropology PhDThank you for citing the above video. It's prelude to the ones I
student named Eriks. Two of her recent videos discuss some of the-
latest developments relating to the origins of human bipedalism:
<https://www.youtube.com/watch?v=kbQAgPSHbZE>
The above is a link to a 32-minute video where Erika discusses several >> >> papers relating to Sahelanthropus tchadensis. This fossil is
remarkable in part because it's dated to about 7mya and was found in
central-african Chad, and also because it may be the oldest bipedal
hominin fossil found to date. However, there appears to be strong
disagreement whether the evidence supports bipedalism.
<https://www.youtube.com/watch?v=Nwkfkp360ps>
The above is a link to a 22-minute video where Erika discusses several >> >> hypotheses about *why* our ancestors shifted to obligate bipedalism.
She discusses several hypotheses, and presents compelling arguments
for her preferred one.
Video by Erika on Lucy bipedalism: https://youtu.be/jo2ZLnucuHY
cited, and refers to them, and so complete a logical trilogy.
In another video, she says that Sahelanthropus was the LCA of Homo / Pan, (though probably just in the general sense). https://www.youtube.com/watch?v=g4FTbZLkpzU&t=7s
In my view, Sahelanthropus is just a southwestern European Miocene ape, very similar to their eastern and northern kin. I see nothing palmigrade in any Miocene ape.
different from palmigrady.At 3:40 she talks about different modes of arboreal locomotion...she mentions "generalized miocene ape" & similar to "palmigrade pronograde arboreal quadrupeds of the miocene'.Erika says this:
To me, the European miocene apes were arboreal slow bimanual brachiating & slow upright bipedal walking on horizontal tree branches.
Is she referring to African miocene apes being pronograde palmigrade?
*********************************
Obviously australopithecus afarensis didn't evolve from a chimp but
from sort of generalized Miocene ape. But that being said, the
morphology of modern chimpanzees is at least similar to some of our
palmigrade pronograde arboreal quadrupeds of the Miocene.
*********************************
So yes, Erika is saying at least some African Miocene apes were
palmigrade aka foot parallel to the ground pronograde aka spine
parallel to the ground, similar to modern chimpanzees.
Chimps aren't palmigrade, no extant ape is, all monkeys are obligatory palmigrade. Humans are palmigrade only during infancy while knee-crawling and bear-walking (I'd guess only within a dome shelter). Humans and chimps hold tools in hands, but that's
I don't know enough about Miocene apes to say if European and African
apes were different. My understanding is climate change caused
European Miocene apes to go extinct before Australopiths evolved in
Africa, which suggests to me the two environments were different
enough to support the differences you describe.
I opine that European Miocene apes expanded from the Black Sea region after the MSC, some of their descendants included australopiths, Homo etc. entering Africa in waves.
At 7:20, she apparently claims that chimp and gorilla arboreal traits interfere with their terrestrial locomotion "act to negate bipedalism" No, sleeping in bowl nests did that, selecting for short legs & backs.
https://youtu.be/jo2ZLnucuHY?t=451Erika says this:
*********************************************
Either way, the aspects that allow for arboriality found in
australopithecus afarensis are not the same types as the ones that we
find in chimpanzees and gorillas. In the latter two species, the
arboreal aspects
I guess 'aspect' could include arboreal bowl nesting, I thought she meant arboreal locomotion only.
act to negate efficient bipedality,
Not arboreal hylobatids. Bowl sleeping in great apes shrank their leg, achilles & back length.
whereas in
australopithecus afarensis they're sort of removed from it.
The key is whether australopiths & kin had halluces that could swivel outwardly while branch-walking and swivel inwardly while ground-walking.
cerebrum) and wide hips (Venus figurines?) and with Homo sapiens (software replaced mechanistic balancing, except in Khoisan and Andamaner females with very posterior buttocks (steatopygia), selected by long distance trekking.They
allow for arboreal behaviors when necessary but don't
harm the effectiveness of bipedality when the animal came down to the
ground.
*********************************************
Erika doesn't argue the cause for these arboreal aspects, but only
that their presence in chimpanzees and gorillas inhibits efficient
bipedality. Anybody who has seen videos of gorillas and chimpanzees
walking bipedally would agree they are much less efficient at it than
are humans. Erika's point in paraphrase is that Lucy had a big butt, I
cannot lie, and so walked more like humans do.
Consider my earlier point about Homo erectus: thick heavy femur and skull occiput mechanically improved balance and pace while ground-walking orthogonally; this continued with neanderthals with pronounced occipital bun (bone + enlarged posteriorly
I wanted to go in depth on this video, but there is a massive noisy halloween celebration of trick or treating goblins and princesses here at the library. So enough.I hope you find time once the ghosts and goblins have gone.
On Thursday, November 3, 2022 at 12:06:26 PM UTC-4, Daud Deden wrote:sahelanthropus. At 6:20 Erika claims Miocene apes didn't knucklewalk (since their hands were more like humans than chimps), then she claims they were "pronograde palmigrade like most monkeys do today", that is false, they occasionally ground walked
On Thursday, November 3, 2022 at 10:56:06 AM UTC-4, Daud Deden wrote:
On Tuesday, November 1, 2022 at 4:17:31 AM UTC-4, 69jp...@gmail.com wrote:
On Mon, 31 Oct 2022 15:15:01 -0700 (PDT), Daud Deden <daud....@gmail.com> wrote:
Sahelanthropus has a flatter skull than modern chimps & humans. Chimps have a more prognathic muzzle, due to knucklewalking pronograde, derived from an ancestor with orthognathic muzzle. Chimp infant muzzles are more humanlike, more likeIn another video, Top 3 Misconceptions about human evolution, she says that Sahelanthropus was the LCA of Homo / Pan, (though probably just in the general sense). https://www.youtube.com/watch?v=g4FTbZLkpzU&t=7sOn Monday, October 24, 2022 at 2:50:22 AM UTC-4, 69jp...@gmail.com wrote:Thank you for citing the above video. It's prelude to the ones I cited, and refers to them, and so complete a logical trilogy.
Gutsick Gibbon is the Youtube handle of a biological anthropology PhD-
student named Eriks. Two of her recent videos discuss some of the >> latest developments relating to the origins of human bipedalism:
<https://www.youtube.com/watch?v=kbQAgPSHbZE>
The above is a link to a 32-minute video where Erika discusses several
papers relating to Sahelanthropus tchadensis. This fossil is
remarkable in part because it's dated to about 7mya and was found in
central-african Chad, and also because it may be the oldest bipedal >> hominin fossil found to date. However, there appears to be strong >> disagreement whether the evidence supports bipedalism.
<https://www.youtube.com/watch?v=Nwkfkp360ps>
The above is a link to a 22-minute video where Erika discusses several
hypotheses about *why* our ancestors shifted to obligate bipedalism.
She discusses several hypotheses, and presents compelling arguments >> for her preferred one.
Video by Erika on Lucy bipedalism: https://youtu.be/jo2ZLnucuHY
In my view, Sahelanthropus is just a southwestern European Miocene ape, very similar to their eastern and northern kin. I see nothing palmigrade in any Miocene ape.
that's different from palmigrady.At 3:40 she talks about different modes of arboreal locomotion...she mentions "generalized miocene ape" & similar to "palmigrade pronograde arboreal quadrupeds of the miocene'.*********************************
To me, the European miocene apes were arboreal slow bimanual brachiating & slow upright bipedal walking on horizontal tree branches.
Is she referring to African miocene apes being pronograde palmigrade? Erika says this:
Obviously australopithecus afarensis didn't evolve from a chimp but from sort of generalized Miocene ape. But that being said, the morphology of modern chimpanzees is at least similar to some of our palmigrade pronograde arboreal quadrupeds of the Miocene. *********************************
So yes, Erika is saying at least some African Miocene apes were palmigrade aka foot parallel to the ground pronograde aka spine parallel to the ground, similar to modern chimpanzees.Chimps aren't palmigrade, no extant ape is, all monkeys are obligatory palmigrade. Humans are palmigrade only during infancy while knee-crawling and bear-walking (I'd guess only within a dome shelter). Humans and chimps hold tools in hands, but
cerebrum) and wide hips (Venus figurines?) and with Homo sapiens (software replaced mechanistic balancing, except in Khoisan and Andamaner females with very posterior buttocks (steatopygia), selected by long distance trekking.I don't know enough about Miocene apes to say if European and African apes were different. My understanding is climate change caused European Miocene apes to go extinct before Australopiths evolved in Africa, which suggests to me the two environments were different enough to support the differences you describe.I opine that European Miocene apes expanded from the Black Sea region after the MSC, some of their descendants included australopiths, Homo etc. entering Africa in waves.
At 7:20, she apparently claims that chimp and gorilla arboreal traits interfere with their terrestrial locomotion "act to negate bipedalism" No, sleeping in bowl nests did that, selecting for short legs & backs.I guess 'aspect' could include arboreal bowl nesting, I thought she meant arboreal locomotion only.
https://youtu.be/jo2ZLnucuHY?t=451Erika says this:
***********************************************
Either way, the aspects that allow for arboriality found in australopithecus afarensis are not the same types as the ones that we find in chimpanzees and gorillas. In the latter two species, the arboreal aspects
act to negate efficient bipedality,
Not arboreal hylobatids. Bowl sleeping in great apes shrank their leg, achilles & back length.
whereas in
australopithecus afarensis they're sort of removed from it.The key is whether australopiths & kin had halluces that could swivel outwardly while branch-walking and swivel inwardly while ground-walking.
They
allow for arboreal behaviors when necessary but don't
harm the effectiveness of bipedality when the animal came down to the ground.
*********************************************
Erika doesn't argue the cause for these arboreal aspects, but only that their presence in chimpanzees and gorillas inhibits efficient bipedality. Anybody who has seen videos of gorillas and chimpanzees walking bipedally would agree they are much less efficient at it than are humans. Erika's point in paraphrase is that Lucy had a big butt, I cannot lie, and so walked more like humans do.Consider my earlier point about Homo erectus: thick heavy femur and skull occiput mechanically improved balance and pace while ground-walking orthogonally; this continued with neanderthals with pronounced occipital bun (bone + enlarged posteriorly
should be 'hominoids', 'particularity' is not a word, gibbons have a *long* spine, and are the only (fast) brachiators.I note that Wikipedia's article on brachiation is quite useful, but contains a blatant stupid falsehood. https://en.wikipedia.org/wiki/BrachiationI wanted to go in depth on this video, but there is a massive noisy halloween celebration of trick or treating goblins and princesses here at the library. So enough.I hope you find time once the ghosts and goblins have gone.
'Currently, researchers classify gibbons and siamangs as the only true brachiators and classify the great apes as modified brachiators. Some traits that allow primates to brachiate include a short spine (particularity the lumbar spine)' [DD: 'primates'
Never trust Wikipedia to get it right.]
On Thu, 3 Nov 2022 07:56:05 -0700 (PDT), Daud DedenYes, I claim it is *descended from* European Miocene apes of the Black Sea region.
<daud....@gmail.com> wrote:
On Tuesday, November 1, 2022 at 4:17:31 AM UTC-4, 69jp...@gmail.com wrote: >> On Mon, 31 Oct 2022 15:15:01 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Monday, October 24, 2022 at 2:50:22 AM UTC-4, 69jp...@gmail.com wrote:Thank you for citing the above video. It's prelude to the ones I
Gutsick Gibbon is the Youtube handle of a biological anthropology PhD >> >> student named Eriks. Two of her recent videos discuss some of the-
latest developments relating to the origins of human bipedalism:
<https://www.youtube.com/watch?v=kbQAgPSHbZE>
The above is a link to a 32-minute video where Erika discusses several >> >> papers relating to Sahelanthropus tchadensis. This fossil is
remarkable in part because it's dated to about 7mya and was found in >> >> central-african Chad, and also because it may be the oldest bipedal
hominin fossil found to date. However, there appears to be strong
disagreement whether the evidence supports bipedalism.
<https://www.youtube.com/watch?v=Nwkfkp360ps>
The above is a link to a 22-minute video where Erika discusses several >> >> hypotheses about *why* our ancestors shifted to obligate bipedalism. >> >> She discusses several hypotheses, and presents compelling arguments
for her preferred one.
Video by Erika on Lucy bipedalism: https://youtu.be/jo2ZLnucuHY
cited, and refers to them, and so complete a logical trilogy.
In another video, she says that Sahelanthropus was the LCA of Homo / Pan, (though probably just in the general sense). https://www.youtube.com/watch?v=g4FTbZLkpzU&t=7sSahelanthropus tchadensis is neither Miocene nor European, but is a
In my view, Sahelanthropus is just a southwestern European Miocene ape *Descendant*, very similar to their eastern and northern kin. I see nothing palmigrade in any Miocene ape.
Pliocene central African species.
different from palmigrady.At 3:40 she talks about different modes of arboreal locomotion...she mentions "generalized miocene ape" & similar to "palmigrade pronograde arboreal quadrupeds of the miocene'.Erika says this:
To me, the European miocene apes were arboreal slow bimanual brachiating & slow upright bipedal walking on horizontal tree branches.
Is she referring to African miocene apes being pronograde palmigrade?
*********************************
Obviously australopithecus afarensis didn't evolve from a chimp but
from sort of generalized Miocene ape. But that being said, the
morphology of modern chimpanzees is at least similar to some of our
palmigrade pronograde arboreal quadrupeds of the Miocene.
*********************************
So yes, Erika is saying at least some African Miocene apes were
palmigrade aka foot parallel to the ground pronograde aka spine
parallel to the ground, similar to modern chimpanzees.
Chimps aren't palmigrade, no extant ape is, all monkeys are obligatory palmigrade. Humans are palmigrade only during infancy while knee-crawling and bear-walking (I'd guess only within a dome shelter). Humans and chimps hold tools in hands, but that's
You seem to have mixed palmigrade with pronograde.
I don't know enough about Miocene apes to say if European and African
apes were different. My understanding is climate change caused
European Miocene apes to go extinct before Australopiths evolved in
Africa, which suggests to me the two environments were different
enough to support the differences you describe.
I opine that European Miocene apes expanded from the Black Sea region after the MSC, some of their descendants included australopiths, Homo etc. entering Africa in waves.
At 7:20, she apparently claims that chimp and gorilla arboreal traits interfere with their terrestrial locomotion "act to negate bipedalism" No, sleeping in bowl nests did that, selecting for short legs & backs.
https://youtu.be/jo2ZLnucuHY?t=451Erika says this:
*********************************************
Either way, the aspects that allow for arboriality found in
australopithecus afarensis are not the same types as the ones that we
find in chimpanzees and gorillas. In the latter two species, the
arboreal aspects
I guess 'aspect' could include arboreal bowl nesting, I thought she meant arboreal locomotion only.
act to negate efficient bipedality,
Not arboreal hylobatids. Bowl sleeping in great apes shrank their leg, achilles & back length.My understanding is, when Erika refers to bipedality without
qualifiers, she means terrestrial bipedality.
whereas in
australopithecus afarensis they're sort of removed from it.
The key is whether australopiths & kin had halluces that could swivel outwardly while branch-walking and swivel inwardly while ground-walking.Erika persuasively argues that an outward hallux would help to
stabilize a not-fully-developed terrestrial bipedal stance.
cerebrum) and wide hips (Venus figurines?) and with Homo sapiens (software replaced mechanistic balancing, except in Khoisan and Andamaner females with very posterior buttocks (steatopygia), selected by long distance trekking.They
allow for arboreal behaviors when necessary but don't
harm the effectiveness of bipedality when the animal came down to the
ground.
*********************************************
Erika doesn't argue the cause for these arboreal aspects, but only
that their presence in chimpanzees and gorillas inhibits efficient
bipedality. Anybody who has seen videos of gorillas and chimpanzees
walking bipedally would agree they are much less efficient at it than
are humans. Erika's point in paraphrase is that Lucy had a big butt, I
cannot lie, and so walked more like humans do.
Consider my earlier point about Homo erectus: thick heavy femur and skull occiput mechanically improved balance and pace while ground-walking orthogonally; this continued with neanderthals with pronounced occipital bun (bone + enlarged posteriorly
I wanted to go in depth on this video, but there is a massive noisy halloween celebration of trick or treating goblins and princesses here at the library. So enough.I hope you find time once the ghosts and goblins have gone.
On Thursday, November 3, 2022 at 6:29:01 PM UTC-4, 69jp...@gmail.com wrote:
On Thu, 3 Nov 2022 07:56:05 -0700 (PDT), Daud DedenYes, I claim it is *descended from* European Miocene apes of the Black Sea region.
<daud....@gmail.com> wrote:
On Tuesday, November 1, 2022 at 4:17:31 AM UTC-4, 69jp...@gmail.com wrote: >> >> On Mon, 31 Oct 2022 15:15:01 -0700 (PDT), Daud DedenSahelanthropus tchadensis is neither Miocene nor European, but is a
<daud....@gmail.com> wrote:
On Monday, October 24, 2022 at 2:50:22 AM UTC-4, 69jp...@gmail.com wrote:Thank you for citing the above video. It's prelude to the ones I
Gutsick Gibbon is the Youtube handle of a biological anthropology PhD >> >> >> student named Eriks. Two of her recent videos discuss some of the-
latest developments relating to the origins of human bipedalism:
<https://www.youtube.com/watch?v=kbQAgPSHbZE>
The above is a link to a 32-minute video where Erika discusses several
papers relating to Sahelanthropus tchadensis. This fossil is
remarkable in part because it's dated to about 7mya and was found in >> >> >> central-african Chad, and also because it may be the oldest bipedal >> >> >> hominin fossil found to date. However, there appears to be strong
disagreement whether the evidence supports bipedalism.
<https://www.youtube.com/watch?v=Nwkfkp360ps>
The above is a link to a 22-minute video where Erika discusses several
hypotheses about *why* our ancestors shifted to obligate bipedalism. >> >> >> She discusses several hypotheses, and presents compelling arguments >> >> >> for her preferred one.
Video by Erika on Lucy bipedalism: https://youtu.be/jo2ZLnucuHY
cited, and refers to them, and so complete a logical trilogy.
In another video, she says that Sahelanthropus was the LCA of Homo / Pan, (though probably just in the general sense). https://www.youtube.com/watch?v=g4FTbZLkpzU&t=7s
In my view, Sahelanthropus is just a southwestern European Miocene ape *Descendant*, very similar to their eastern and northern kin. I see nothing palmigrade in any Miocene ape.
Pliocene central African species.
s different from palmigrady.At 3:40 she talks about different modes of arboreal locomotion...she mentions "generalized miocene ape" & similar to "palmigrade pronograde arboreal quadrupeds of the miocene'.*********************************
To me, the European miocene apes were arboreal slow bimanual brachiating & slow upright bipedal walking on horizontal tree branches.
Is she referring to African miocene apes being pronograde palmigrade? >> >> Erika says this:
Obviously australopithecus afarensis didn't evolve from a chimp but
from sort of generalized Miocene ape. But that being said, the
morphology of modern chimpanzees is at least similar to some of our
palmigrade pronograde arboreal quadrupeds of the Miocene.
*********************************
So yes, Erika is saying at least some African Miocene apes were
palmigrade aka foot parallel to the ground pronograde aka spine
parallel to the ground, similar to modern chimpanzees.
Chimps aren't palmigrade, no extant ape is, all monkeys are obligatory palmigrade. Humans are palmigrade only during infancy while knee-crawling and bear-walking (I'd guess only within a dome shelter). Humans and chimps hold tools in hands, but that'
You seem to have mixed palmigrade with pronograde.
Please cite specifically where I seem to have done that.
biped. Our toes have shortened, halluces converged, while our soles have lengthened providing postural stability.My understanding is, when Erika refers to bipedality withoutI don't know enough about Miocene apes to say if European and African
apes were different. My understanding is climate change caused
European Miocene apes to go extinct before Australopiths evolved in
Africa, which suggests to me the two environments were different
enough to support the differences you describe.
I opine that European Miocene apes expanded from the Black Sea region after the MSC, some of their descendants included australopiths, Homo etc. entering Africa in waves.
At 7:20, she apparently claims that chimp and gorilla arboreal traits interfere with their terrestrial locomotion "act to negate bipedalism" No, sleeping in bowl nests did that, selecting for short legs & backs.
https://youtu.be/jo2ZLnucuHY?t=451Erika says this:
*********************************************
Either way, the aspects that allow for arboriality found in
australopithecus afarensis are not the same types as the ones that we
find in chimpanzees and gorillas. In the latter two species, the
arboreal aspects
I guess 'aspect' could include arboreal bowl nesting, I thought she meant arboreal locomotion only.
act to negate efficient bipedality,
Not arboreal hylobatids. Bowl sleeping in great apes shrank their leg, achilles & back length.
qualifiers, she means terrestrial bipedality.
Erika persuasively argues that an outward hallux would help towhereas in
australopithecus afarensis they're sort of removed from it.
The key is whether australopiths & kin had halluces that could swivel outwardly while branch-walking and swivel inwardly while ground-walking.
stabilize a not-fully-developed terrestrial bipedal stance.
I presume that an "outward hallux" is a divergent hallux. That may differ from one that can swivel in or out per need. One that permanently stays divergent is a walking hazard, constantly snagging on vegetation, and would likely be selected against in a
cerebrum) and wide hips (Venus figurines?) and with Homo sapiens (software replaced mechanistic balancing, except in Khoisan and Andamaner females with very posterior buttocks (steatopygia), selected by long distance trekking.They
allow for arboreal behaviors when necessary but don't
harm the effectiveness of bipedality when the animal came down to the
ground.
*********************************************
Erika doesn't argue the cause for these arboreal aspects, but only
that their presence in chimpanzees and gorillas inhibits efficient
bipedality. Anybody who has seen videos of gorillas and chimpanzees
walking bipedally would agree they are much less efficient at it than
are humans. Erika's point in paraphrase is that Lucy had a big butt, I >> >> cannot lie, and so walked more like humans do.
Consider my earlier point about Homo erectus: thick heavy femur and skull occiput mechanically improved balance and pace while ground-walking orthogonally; this continued with neanderthals with pronounced occipital bun (bone + enlarged posteriorly
I wanted to go in depth on this video, but there is a massive noisy halloween celebration of trick or treating goblins and princesses here at the library. So enough.I hope you find time once the ghosts and goblins have gone.
On Thu, 3 Nov 2022 20:32:40 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Thursday, November 3, 2022 at 6:29:01 PM UTC-4, 69jp...@gmail.com wrote: >> On Thu, 3 Nov 2022 07:56:05 -0700 (PDT), Daud DedenMy impression is there isn't enough evidence to show whether Pliocene African apes descended from Miocene European apes or Miocene African
<daud....@gmail.com> wrote:Yes, I claim it is *descended from* European Miocene apes of the Black Sea region.
On Tuesday, November 1, 2022 at 4:17:31 AM UTC-4, 69jp...@gmail.com wrote:Sahelanthropus tchadensis is neither Miocene nor European, but is a
On Mon, 31 Oct 2022 15:15:01 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Monday, October 24, 2022 at 2:50:22 AM UTC-4, 69jp...@gmail.com wrote:Thank you for citing the above video. It's prelude to the ones I
Gutsick Gibbon is the Youtube handle of a biological anthropology PhD-
student named Eriks. Two of her recent videos discuss some of the >> >> >> latest developments relating to the origins of human bipedalism:
<https://www.youtube.com/watch?v=kbQAgPSHbZE>
The above is a link to a 32-minute video where Erika discusses several
papers relating to Sahelanthropus tchadensis. This fossil is
remarkable in part because it's dated to about 7mya and was found in
central-african Chad, and also because it may be the oldest bipedal >> >> >> hominin fossil found to date. However, there appears to be strong >> >> >> disagreement whether the evidence supports bipedalism.
<https://www.youtube.com/watch?v=Nwkfkp360ps>
The above is a link to a 22-minute video where Erika discusses several
hypotheses about *why* our ancestors shifted to obligate bipedalism.
She discusses several hypotheses, and presents compelling arguments >> >> >> for her preferred one.
Video by Erika on Lucy bipedalism: https://youtu.be/jo2ZLnucuHY
cited, and refers to them, and so complete a logical trilogy.
In another video, she says that Sahelanthropus was the LCA of Homo / Pan, (though probably just in the general sense). https://www.youtube.com/watch?v=g4FTbZLkpzU&t=7s
In my view, Sahelanthropus is just a southwestern European Miocene ape *Descendant*, very similar to their eastern and northern kin. I see nothing palmigrade in any Miocene ape.
Pliocene central African species.
apes. Either way, there was enough time between the two eras to have
evolved differences between either Miocene populations and Pliocene S. tchadensis.
that's different from palmigrady.At 3:40 she talks about different modes of arboreal locomotion...she mentions "generalized miocene ape" & similar to "palmigrade pronograde arboreal quadrupeds of the miocene'.*********************************
To me, the European miocene apes were arboreal slow bimanual brachiating & slow upright bipedal walking on horizontal tree branches.
Is she referring to African miocene apes being pronograde palmigrade? >> >> Erika says this:
Obviously australopithecus afarensis didn't evolve from a chimp but
from sort of generalized Miocene ape. But that being said, the
morphology of modern chimpanzees is at least similar to some of our
palmigrade pronograde arboreal quadrupeds of the Miocene.
*********************************
So yes, Erika is saying at least some African Miocene apes were
palmigrade aka foot parallel to the ground pronograde aka spine
parallel to the ground, similar to modern chimpanzees.
Chimps aren't palmigrade, no extant ape is, all monkeys are obligatory palmigrade. Humans are palmigrade only during infancy while knee-crawling and bear-walking (I'd guess only within a dome shelter). Humans and chimps hold tools in hands, but
You seem to have mixed palmigrade with pronograde.
Please cite specifically where I seem to have done that.
Just look at your sentence immediately above the one you challenge. Palmigrade is a scientific term to refer to locomotion with the wholea biped. Our toes have shortened, halluces converged, while our soles have lengthened providing postural stability.
foot on the ground, as with humans and apes when they walk bipedally.
The feet of crawling infants are incidentally vertical to the ground
aka not palmigrade, while their spine is nearly parallel to the ground
aka pronograde.
My understanding is, when Erika refers to bipedality withoutI don't know enough about Miocene apes to say if European and African >> >> apes were different. My understanding is climate change caused
European Miocene apes to go extinct before Australopiths evolved in
Africa, which suggests to me the two environments were different
enough to support the differences you describe.
I opine that European Miocene apes expanded from the Black Sea region after the MSC, some of their descendants included australopiths, Homo etc. entering Africa in waves.
At 7:20, she apparently claims that chimp and gorilla arboreal traits interfere with their terrestrial locomotion "act to negate bipedalism" No, sleeping in bowl nests did that, selecting for short legs & backs.
https://youtu.be/jo2ZLnucuHY?t=451Erika says this:
*********************************************
Either way, the aspects that allow for arboriality found in
australopithecus afarensis are not the same types as the ones that we >> >> find in chimpanzees and gorillas. In the latter two species, the
arboreal aspects
I guess 'aspect' could include arboreal bowl nesting, I thought she meant arboreal locomotion only.
act to negate efficient bipedality,
Not arboreal hylobatids. Bowl sleeping in great apes shrank their leg, achilles & back length.
qualifiers, she means terrestrial bipedality.
Erika persuasively argues that an outward hallux would help towhereas in
australopithecus afarensis they're sort of removed from it.
The key is whether australopiths & kin had halluces that could swivel outwardly while branch-walking and swivel inwardly while ground-walking.
stabilize a not-fully-developed terrestrial bipedal stance.
I presume that an "outward hallux" is a divergent hallux. That may differ from one that can swivel in or out per need. One that permanently stays divergent is a walking hazard, constantly snagging on vegetation, and would likely be selected against in
My understanding is the primitive hallux was anatomically similar to:~}
the pollex, in that it was opposable under voluntary muscular control.
So an "outward" (your word) hallux would not have been an impediment
to walking on the ground. To the contrary, such a feature would be advantageous to organisms which moved both terrestrially and
arboreally.
As you say, modern humans have shortened parallel toes, a derived specialization for efficiently walking long distance on the ground. Personally, I can with difficulty move my big toes only a little in
and out, like some crippled crab. However, I have a good friend who
can move her big toes substantially and strongly, enough to painfully
pinch other people's legs under the table while playing card games, to
good strategic effect.
cerebrum) and wide hips (Venus figurines?) and with Homo sapiens (software replaced mechanistic balancing, except in Khoisan and Andamaner females with very posterior buttocks (steatopygia), selected by long distance trekking.They
allow for arboreal behaviors when necessary but don't
harm the effectiveness of bipedality when the animal came down to the >> >> ground.
*********************************************
Erika doesn't argue the cause for these arboreal aspects, but only
that their presence in chimpanzees and gorillas inhibits efficient
bipedality. Anybody who has seen videos of gorillas and chimpanzees
walking bipedally would agree they are much less efficient at it than >> >> are humans. Erika's point in paraphrase is that Lucy had a big butt, I >> >> cannot lie, and so walked more like humans do.
Consider my earlier point about Homo erectus: thick heavy femur and skull occiput mechanically improved balance and pace while ground-walking orthogonally; this continued with neanderthals with pronounced occipital bun (bone + enlarged posteriorly
I wanted to go in depth on this video, but there is a massive noisy halloween celebration of trick or treating goblins and princesses here at the library. So enough.I hope you find time once the ghosts and goblins have gone.
On Friday, November 4, 2022 at 2:21:56 AM UTC-4, 69jp...@gmail.com wrote:that's different from palmigrady.
On Thu, 3 Nov 2022 20:32:40 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Thursday, November 3, 2022 at 6:29:01 PM UTC-4, 69jp...@gmail.com wrote:My impression is there isn't enough evidence to show whether Pliocene
On Thu, 3 Nov 2022 07:56:05 -0700 (PDT), Daud DedenYes, I claim it is *descended from* European Miocene apes of the Black Sea region.
<daud....@gmail.com> wrote:
On Tuesday, November 1, 2022 at 4:17:31 AM UTC-4, 69jp...@gmail.com wrote:Sahelanthropus tchadensis is neither Miocene nor European, but is a
On Mon, 31 Oct 2022 15:15:01 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Monday, October 24, 2022 at 2:50:22 AM UTC-4, 69jp...@gmail.com wrote:Thank you for citing the above video. It's prelude to the ones I
Gutsick Gibbon is the Youtube handle of a biological anthropology PhD-
student named Eriks. Two of her recent videos discuss some of the >> >> >> >> latest developments relating to the origins of human bipedalism: >> >> >> >>
<https://www.youtube.com/watch?v=kbQAgPSHbZE>
The above is a link to a 32-minute video where Erika discusses several
papers relating to Sahelanthropus tchadensis. This fossil is
remarkable in part because it's dated to about 7mya and was found in
central-african Chad, and also because it may be the oldest bipedal
hominin fossil found to date. However, there appears to be strong >> >> >> >> disagreement whether the evidence supports bipedalism.
<https://www.youtube.com/watch?v=Nwkfkp360ps>
The above is a link to a 22-minute video where Erika discusses several
hypotheses about *why* our ancestors shifted to obligate bipedalism.
She discusses several hypotheses, and presents compelling arguments
for her preferred one.
Video by Erika on Lucy bipedalism: https://youtu.be/jo2ZLnucuHY
cited, and refers to them, and so complete a logical trilogy.
In another video, she says that Sahelanthropus was the LCA of Homo / Pan, (though probably just in the general sense). https://www.youtube.com/watch?v=g4FTbZLkpzU&t=7s
In my view, Sahelanthropus is just a southwestern European Miocene ape *Descendant*, very similar to their eastern and northern kin. I see nothing palmigrade in any Miocene ape.
Pliocene central African species.
African apes descended from Miocene European apes or Miocene African
apes. Either way, there was enough time between the two eras to have
evolved differences between either Miocene populations and Pliocene S.
tchadensis.
I agree. I didn't mean all 'Pliocene African apes', only Sahelanthropus, but might include some others.
At 3:40 she talks about different modes of arboreal locomotion...she mentions "generalized miocene ape" & similar to "palmigrade pronograde arboreal quadrupeds of the miocene'.Erika says this:
To me, the European miocene apes were arboreal slow bimanual brachiating & slow upright bipedal walking on horizontal tree branches.
Is she referring to African miocene apes being pronograde palmigrade?
*********************************
Obviously australopithecus afarensis didn't evolve from a chimp but >> >> >> from sort of generalized Miocene ape. But that being said, the
morphology of modern chimpanzees is at least similar to some of our >> >> >> palmigrade pronograde arboreal quadrupeds of the Miocene.
*********************************
So yes, Erika is saying at least some African Miocene apes were
palmigrade aka foot parallel to the ground pronograde aka spine
parallel to the ground, similar to modern chimpanzees.
Chimps aren't palmigrade, no extant ape is, all monkeys are obligatory palmigrade. Humans are palmigrade only during infancy while knee-crawling and bear-walking (I'd guess only within a dome shelter). Humans and chimps hold tools in hands, but
confusion, (my Bio background is more from botanical than zoological.). Some definitions are warranted.You seem to have mixed palmigrade with pronograde.
Please cite specifically where I seem to have done that.
Just look at your sentence immediately above the one you challenge.
Palmigrade is a scientific term to refer to locomotion with the whole
foot on the ground, as with humans and apes when they walk bipedally.
The feet of crawling infants are incidentally vertical to the ground
aka not palmigrade, while their spine is nearly parallel to the ground
aka pronograde.
Ok, my use of 'palmigrade' was in the palm-only sense, using plantigrade (sole) instead, since we normally refer to animals standing/walking on their feet, not their hands. I'll review things and adjust before responding, thanks for spotlighting the
Palmigrade Etymology
From Latin palma (“palm of the hand”) + gradi (“to walk”).
palmigrade
(zoology) Putting the whole foot upon the ground in walking, as some mammals do
https://wikidiff.com/plantigrade/palmigrade
https://en.m.wikipedia.org/wiki/Plantigrade
Plantigrade mammal species include (but are not limited to): >Some primates (including humans)
Ailuridae: red pandas
Ursidae: bears
in a biped. Our toes have shortened, halluces converged, while our soles have lengthened providing postural stability.My understanding is, when Erika refers to bipedality withoutI don't know enough about Miocene apes to say if European and African >> >> >> apes were different. My understanding is climate change caused
European Miocene apes to go extinct before Australopiths evolved in >> >> >> Africa, which suggests to me the two environments were different
enough to support the differences you describe.
I opine that European Miocene apes expanded from the Black Sea region after the MSC, some of their descendants included australopiths, Homo etc. entering Africa in waves.
At 7:20, she apparently claims that chimp and gorilla arboreal traits interfere with their terrestrial locomotion "act to negate bipedalism" No, sleeping in bowl nests did that, selecting for short legs & backs.
https://youtu.be/jo2ZLnucuHY?t=451Erika says this:
*********************************************
Either way, the aspects that allow for arboriality found in
australopithecus afarensis are not the same types as the ones that we >> >> >> find in chimpanzees and gorillas. In the latter two species, the
arboreal aspects
I guess 'aspect' could include arboreal bowl nesting, I thought she meant arboreal locomotion only.
act to negate efficient bipedality,
Not arboreal hylobatids. Bowl sleeping in great apes shrank their leg, achilles & back length.
qualifiers, she means terrestrial bipedality.
Erika persuasively argues that an outward hallux would help towhereas in
australopithecus afarensis they're sort of removed from it.
The key is whether australopiths & kin had halluces that could swivel outwardly while branch-walking and swivel inwardly while ground-walking.
stabilize a not-fully-developed terrestrial bipedal stance.
I presume that an "outward hallux" is a divergent hallux. That may differ from one that can swivel in or out per need. One that permanently stays divergent is a walking hazard, constantly snagging on vegetation, and would likely be selected against
cerebrum) and wide hips (Venus figurines?) and with Homo sapiens (software replaced mechanistic balancing, except in Khoisan and Andamaner females with very posterior buttocks (steatopygia), selected by long distance trekking.My understanding is the primitive hallux was anatomically similar to:~}
the pollex, in that it was opposable under voluntary muscular control.
So an "outward" (your word) hallux would not have been an impediment
to walking on the ground. To the contrary, such a feature would be
advantageous to organisms which moved both terrestrially and
arboreally.
As you say, modern humans have shortened parallel toes, a derived
specialization for efficiently walking long distance on the ground.
Personally, I can with difficulty move my big toes only a little in
and out, like some crippled crab. However, I have a good friend who
can move her big toes substantially and strongly, enough to painfully
pinch other people's legs under the table while playing card games, to
good strategic effect.
They
allow for arboreal behaviors when necessary but don't
harm the effectiveness of bipedality when the animal came down to the >> >> >> ground.
*********************************************
Erika doesn't argue the cause for these arboreal aspects, but only
that their presence in chimpanzees and gorillas inhibits efficient
bipedality. Anybody who has seen videos of gorillas and chimpanzees >> >> >> walking bipedally would agree they are much less efficient at it than >> >> >> are humans. Erika's point in paraphrase is that Lucy had a big butt, I
cannot lie, and so walked more like humans do.
Consider my earlier point about Homo erectus: thick heavy femur and skull occiput mechanically improved balance and pace while ground-walking orthogonally; this continued with neanderthals with pronounced occipital bun (bone + enlarged posteriorly
I wanted to go in depth on this video, but there is a massive noisy halloween celebration of trick or treating goblins and princesses here at the library. So enough.I hope you find time once the ghosts and goblins have gone.
On Fri, 4 Nov 2022 11:01:30 -0700 (PDT), Daud Dedenthat's different from palmigrady.
<daud....@gmail.com> wrote:
On Friday, November 4, 2022 at 2:21:56 AM UTC-4, 69jp...@gmail.com wrote: >> On Thu, 3 Nov 2022 20:32:40 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Thursday, November 3, 2022 at 6:29:01 PM UTC-4, 69jp...@gmail.com wrote:My impression is there isn't enough evidence to show whether Pliocene
On Thu, 3 Nov 2022 07:56:05 -0700 (PDT), Daud DedenYes, I claim it is *descended from* European Miocene apes of the Black Sea region.
<daud....@gmail.com> wrote:
On Tuesday, November 1, 2022 at 4:17:31 AM UTC-4, 69jp...@gmail.com wrote:Sahelanthropus tchadensis is neither Miocene nor European, but is a
On Mon, 31 Oct 2022 15:15:01 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Monday, October 24, 2022 at 2:50:22 AM UTC-4, 69jp...@gmail.com wrote:Thank you for citing the above video. It's prelude to the ones I
Gutsick Gibbon is the Youtube handle of a biological anthropology PhD-
student named Eriks. Two of her recent videos discuss some of the
latest developments relating to the origins of human bipedalism: >> >> >> >>
<https://www.youtube.com/watch?v=kbQAgPSHbZE>
The above is a link to a 32-minute video where Erika discusses several
papers relating to Sahelanthropus tchadensis. This fossil is
remarkable in part because it's dated to about 7mya and was found in
central-african Chad, and also because it may be the oldest bipedal
hominin fossil found to date. However, there appears to be strong
disagreement whether the evidence supports bipedalism.
<https://www.youtube.com/watch?v=Nwkfkp360ps>
The above is a link to a 22-minute video where Erika discusses several
hypotheses about *why* our ancestors shifted to obligate bipedalism.
She discusses several hypotheses, and presents compelling arguments
for her preferred one.
Video by Erika on Lucy bipedalism: https://youtu.be/jo2ZLnucuHY
cited, and refers to them, and so complete a logical trilogy.
In another video, she says that Sahelanthropus was the LCA of Homo / Pan, (though probably just in the general sense). https://www.youtube.com/watch?v=g4FTbZLkpzU&t=7s
In my view, Sahelanthropus is just a southwestern European Miocene ape *Descendant*, very similar to their eastern and northern kin. I see nothing palmigrade in any Miocene ape.
Pliocene central African species.
African apes descended from Miocene European apes or Miocene African
apes. Either way, there was enough time between the two eras to have
evolved differences between either Miocene populations and Pliocene S.
tchadensis.
I agree. I didn't mean all 'Pliocene African apes', only Sahelanthropus, but might include some others.
At 3:40 she talks about different modes of arboreal locomotion...she mentions "generalized miocene ape" & similar to "palmigrade pronograde arboreal quadrupeds of the miocene'.Erika says this:
To me, the European miocene apes were arboreal slow bimanual brachiating & slow upright bipedal walking on horizontal tree branches.
Is she referring to African miocene apes being pronograde palmigrade?
*********************************
Obviously australopithecus afarensis didn't evolve from a chimp but >> >> >> from sort of generalized Miocene ape. But that being said, the
morphology of modern chimpanzees is at least similar to some of our >> >> >> palmigrade pronograde arboreal quadrupeds of the Miocene.
*********************************
So yes, Erika is saying at least some African Miocene apes were
palmigrade aka foot parallel to the ground pronograde aka spine
parallel to the ground, similar to modern chimpanzees.
Chimps aren't palmigrade, no extant ape is, all monkeys are obligatory palmigrade. Humans are palmigrade only during infancy while knee-crawling and bear-walking (I'd guess only within a dome shelter). Humans and chimps hold tools in hands, but
confusion, (my Bio background is more from botanical than zoological.). Some definitions are warranted.You seem to have mixed palmigrade with pronograde.
Please cite specifically where I seem to have done that.
Just look at your sentence immediately above the one you challenge.
Palmigrade is a scientific term to refer to locomotion with the whole
foot on the ground, as with humans and apes when they walk bipedally.
The feet of crawling infants are incidentally vertical to the ground
aka not palmigrade, while their spine is nearly parallel to the ground
aka pronograde.
Ok, my use of 'palmigrade' was in the palm-only sense, using plantigrade (sole) instead, since we normally refer to animals standing/walking on their feet, not their hands. I'll review things and adjust before responding, thanks for spotlighting the
Yes, both can be noun or adjective as needed, -grade, -grady.Palmigrade Etymology
From Latin palma (“palm of the hand”) + gradi (“to walk”).
palmigrade
(zoology) Putting the whole foot upon the ground in walking, as some mammals do
https://wikidiff.com/plantigrade/palmigrade
https://en.m.wikipedia.org/wiki/PlantigradeOk. I too am unfamiliar with the distinction between palmigrade and plantigrade. One source I found said "palmigrade" is an adjective and "plantigrade" is a noun, but that just adds to the confusion.
Plantigrade mammal species include (but are not limited to):
Some primates (including humans)
Ailuridae: red pandas
Ursidae: bears
Anatomically, the relevant distinction is how much of the foot restsYes. Knucklewalking fits in-between, plantigrade hind limbs & digitigrade (dorsal) forelimbs.
on the ground when walking, either plantigrade, digitigrade or
unguligrade.
For primates, the importance of fingers as manipulating tools meansYes. Rainforest drills have shortish fingers, they walk on their fingertips not palms.
they necessarily compromise the hand's anatomy for locomotion. For
arboreal primates, the phalanges are curved to better grasp branches.
For quadruped primates, the hands may be flat on the ground as with
baboons. Facultative bipedal primates may use knuckle-walking as with chimpanzees.
For obligate bipeds like genus homo, the hands aren't used forI liked this Sci Am article, especially near the end, section called Open Question.
locomotion at all, and their anatomy is devoted to manipulation. My understanding is genus australopithecus are transitional between
arboreal bipedal primates and terrestrial bipedal primates.
in a biped. Our toes have shortened, halluces converged, while our soles have lengthened providing postural stability.My understanding is, when Erika refers to bipedality withoutI don't know enough about Miocene apes to say if European and African
apes were different. My understanding is climate change caused
European Miocene apes to go extinct before Australopiths evolved in >> >> >> Africa, which suggests to me the two environments were different
enough to support the differences you describe.
I opine that European Miocene apes expanded from the Black Sea region after the MSC, some of their descendants included australopiths, Homo etc. entering Africa in waves.
At 7:20, she apparently claims that chimp and gorilla arboreal traits interfere with their terrestrial locomotion "act to negate bipedalism" No, sleeping in bowl nests did that, selecting for short legs & backs.
https://youtu.be/jo2ZLnucuHY?t=451Erika says this:
*********************************************
Either way, the aspects that allow for arboriality found in
australopithecus afarensis are not the same types as the ones that we
find in chimpanzees and gorillas. In the latter two species, the
arboreal aspects
I guess 'aspect' could include arboreal bowl nesting, I thought she meant arboreal locomotion only.
act to negate efficient bipedality,
Not arboreal hylobatids. Bowl sleeping in great apes shrank their leg, achilles & back length.
qualifiers, she means terrestrial bipedality.
Erika persuasively argues that an outward hallux would help towhereas in
australopithecus afarensis they're sort of removed from it.
The key is whether australopiths & kin had halluces that could swivel outwardly while branch-walking and swivel inwardly while ground-walking.
stabilize a not-fully-developed terrestrial bipedal stance.
I presume that an "outward hallux" is a divergent hallux. That may differ from one that can swivel in or out per need. One that permanently stays divergent is a walking hazard, constantly snagging on vegetation, and would likely be selected against
posteriorly cerebrum) and wide hips (Venus figurines?) and with Homo sapiens (software replaced mechanistic balancing, except in Khoisan and Andamaner females with very posterior buttocks (steatopygia), selected by long distance trekking.My understanding is the primitive hallux was anatomically similar to:~}
the pollex, in that it was opposable under voluntary muscular control.
So an "outward" (your word) hallux would not have been an impediment
to walking on the ground. To the contrary, such a feature would be
advantageous to organisms which moved both terrestrially and
arboreally.
As you say, modern humans have shortened parallel toes, a derived
specialization for efficiently walking long distance on the ground.
Personally, I can with difficulty move my big toes only a little in
and out, like some crippled crab. However, I have a good friend who
can move her big toes substantially and strongly, enough to painfully
pinch other people's legs under the table while playing card games, to
good strategic effect.
They
allow for arboreal behaviors when necessary but don't
harm the effectiveness of bipedality when the animal came down to the
ground.
*********************************************
Erika doesn't argue the cause for these arboreal aspects, but only >> >> >> that their presence in chimpanzees and gorillas inhibits efficient >> >> >> bipedality. Anybody who has seen videos of gorillas and chimpanzees >> >> >> walking bipedally would agree they are much less efficient at it than
are humans. Erika's point in paraphrase is that Lucy had a big butt, I
cannot lie, and so walked more like humans do.
Consider my earlier point about Homo erectus: thick heavy femur and skull occiput mechanically improved balance and pace while ground-walking orthogonally; this continued with neanderthals with pronounced occipital bun (bone + enlarged
I wanted to go in depth on this video, but there is a massive noisy halloween celebration of trick or treating goblins and princesses here at the library. So enough.I hope you find time once the ghosts and goblins have gone.
As you say, modern humans have shortened parallel toes, a derived specialization for efficiently walking long distance on the ground. Personally, I can with difficulty move my big toes only a little in
and out, like some crippled crab. However, I have a good friend who
can move her big toes substantially and strongly, enough to painfully
pinch other people's legs under the table while playing card games, to
good strategic effect.
<Full snip for focus>
As you say, modern humans have shortened parallel toes, a derived
specialization for efficiently walking long distance on the ground.
Personally, I can with difficulty move my big toes only a little in
and out, like some crippled crab. However, I have a good friend who
can move her big toes substantially and strongly, enough to painfully
pinch other people's legs under the table while playing card games, to
good strategic effect.
Our comfy confining cushioned shoes can cripple... this video short shows Barefoot shoes can return them to health. https://youtube.com/shorts/EOxOrxggBMI?feature=share
On Saturday, November 5, 2022 at 2:25:13 AM UTC-4, 69jp...@gmail.com wrote:that's different from palmigrady.
On Fri, 4 Nov 2022 11:01:30 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Friday, November 4, 2022 at 2:21:56 AM UTC-4, 69jp...@gmail.com wrote: >> >> On Thu, 3 Nov 2022 20:32:40 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Thursday, November 3, 2022 at 6:29:01 PM UTC-4, 69jp...@gmail.com wrote:My impression is there isn't enough evidence to show whether Pliocene
On Thu, 3 Nov 2022 07:56:05 -0700 (PDT), Daud DedenYes, I claim it is *descended from* European Miocene apes of the Black Sea region.
<daud....@gmail.com> wrote:
On Tuesday, November 1, 2022 at 4:17:31 AM UTC-4, 69jp...@gmail.com wrote:Sahelanthropus tchadensis is neither Miocene nor European, but is a >> >> >> Pliocene central African species.
On Mon, 31 Oct 2022 15:15:01 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Monday, October 24, 2022 at 2:50:22 AM UTC-4, 69jp...@gmail.com wrote:
Gutsick Gibbon is the Youtube handle of a biological anthropology PhD-
student named Eriks. Two of her recent videos discuss some of the
latest developments relating to the origins of human bipedalism:
<https://www.youtube.com/watch?v=kbQAgPSHbZE>
The above is a link to a 32-minute video where Erika discusses several
papers relating to Sahelanthropus tchadensis. This fossil is
remarkable in part because it's dated to about 7mya and was found in
central-african Chad, and also because it may be the oldest bipedal
hominin fossil found to date. However, there appears to be strong
disagreement whether the evidence supports bipedalism.
<https://www.youtube.com/watch?v=Nwkfkp360ps>
The above is a link to a 22-minute video where Erika discusses several
hypotheses about *why* our ancestors shifted to obligate bipedalism.
She discusses several hypotheses, and presents compelling arguments
for her preferred one.
Video by Erika on Lucy bipedalism: https://youtu.be/jo2ZLnucuHY >> >> >> >> Thank you for citing the above video. It's prelude to the ones I >> >> >> >> cited, and refers to them, and so complete a logical trilogy.
In another video, she says that Sahelanthropus was the LCA of Homo / Pan, (though probably just in the general sense). https://www.youtube.com/watch?v=g4FTbZLkpzU&t=7s
In my view, Sahelanthropus is just a southwestern European Miocene ape *Descendant*, very similar to their eastern and northern kin. I see nothing palmigrade in any Miocene ape.
African apes descended from Miocene European apes or Miocene African
apes. Either way, there was enough time between the two eras to have
evolved differences between either Miocene populations and Pliocene S. >> >> tchadensis.
I agree. I didn't mean all 'Pliocene African apes', only Sahelanthropus, but might include some others.
At 3:40 she talks about different modes of arboreal locomotion...she mentions "generalized miocene ape" & similar to "palmigrade pronograde arboreal quadrupeds of the miocene'.Erika says this:
To me, the European miocene apes were arboreal slow bimanual brachiating & slow upright bipedal walking on horizontal tree branches.
Is she referring to African miocene apes being pronograde palmigrade?
*********************************
Obviously australopithecus afarensis didn't evolve from a chimp but
from sort of generalized Miocene ape. But that being said, the
morphology of modern chimpanzees is at least similar to some of our
palmigrade pronograde arboreal quadrupeds of the Miocene.
*********************************
So yes, Erika is saying at least some African Miocene apes were
palmigrade aka foot parallel to the ground pronograde aka spine
parallel to the ground, similar to modern chimpanzees.
Chimps aren't palmigrade, no extant ape is, all monkeys are obligatory palmigrade. Humans are palmigrade only during infancy while knee-crawling and bear-walking (I'd guess only within a dome shelter). Humans and chimps hold tools in hands, but
confusion, (my Bio background is more from botanical than zoological.). Some definitions are warranted.You seem to have mixed palmigrade with pronograde.
Please cite specifically where I seem to have done that.
Just look at your sentence immediately above the one you challenge.
Palmigrade is a scientific term to refer to locomotion with the whole
foot on the ground, as with humans and apes when they walk bipedally.
The feet of crawling infants are incidentally vertical to the ground
aka not palmigrade, while their spine is nearly parallel to the ground >> >> aka pronograde.
Ok, my use of 'palmigrade' was in the palm-only sense, using plantigrade (sole) instead, since we normally refer to animals standing/walking on their feet, not their hands. I'll review things and adjust before responding, thanks for spotlighting the
Yes, both can be noun or adjective as needed, -grade, -grady.Ok. I too am unfamiliar with the distinction between palmigrade and
Palmigrade Etymology
From Latin palma (“palm of the hand”) + gradi (“to walk”).
palmigrade
(zoology) Putting the whole foot upon the ground in walking, as some mammals do
https://wikidiff.com/plantigrade/palmigrade
https://en.m.wikipedia.org/wiki/Plantigrade
Plantigrade mammal species include (but are not limited to):
Some primates (including humans)
Ailuridae: red pandas
Ursidae: bears
plantigrade. One source I found said "palmigrade" is an adjective and
"plantigrade" is a noun, but that just adds to the confusion.
Anatomically, the relevant distinction is how much of the foot restsYes. Knucklewalking fits in-between, plantigrade hind limbs & digitigrade (dorsal) forelimbs.
on the ground when walking, either plantigrade, digitigrade or
unguligrade.
For primates, the importance of fingers as manipulating tools meansYes. Rainforest drills have shortish fingers, they walk on their fingertips not palms.
they necessarily compromise the hand's anatomy for locomotion. For
arboreal primates, the phalanges are curved to better grasp branches.
For quadruped primates, the hands may be flat on the ground as with
baboons. Facultative bipedal primates may use knuckle-walking as with
chimpanzees.
For obligate bipeds like genus homo, the hands aren't used forI liked this Sci Am article, especially near the end, section called Open Question.
locomotion at all, and their anatomy is devoted to manipulation. My
understanding is genus australopithecus are transitional between
arboreal bipedal primates and terrestrial bipedal primates.
https://www.scientificamerican.com/article/fossils-upend-conventional-wisdom-about-evolution-of-human-bipedalism/
against in a biped. Our toes have shortened, halluces converged, while our soles have lengthened providing postural stability.My understanding is, when Erika refers to bipedality withoutI don't know enough about Miocene apes to say if European and African
apes were different. My understanding is climate change caused
European Miocene apes to go extinct before Australopiths evolved in
Africa, which suggests to me the two environments were different >> >> >> >> enough to support the differences you describe.
I opine that European Miocene apes expanded from the Black Sea region after the MSC, some of their descendants included australopiths, Homo etc. entering Africa in waves.
At 7:20, she apparently claims that chimp and gorilla arboreal traits interfere with their terrestrial locomotion "act to negate bipedalism" No, sleeping in bowl nests did that, selecting for short legs & backs.
https://youtu.be/jo2ZLnucuHY?t=451Erika says this:
*********************************************
Either way, the aspects that allow for arboriality found in
australopithecus afarensis are not the same types as the ones that we
find in chimpanzees and gorillas. In the latter two species, the >> >> >> >> arboreal aspects
I guess 'aspect' could include arboreal bowl nesting, I thought she meant arboreal locomotion only.
act to negate efficient bipedality,
Not arboreal hylobatids. Bowl sleeping in great apes shrank their leg, achilles & back length.
qualifiers, she means terrestrial bipedality.
Erika persuasively argues that an outward hallux would help towhereas in
australopithecus afarensis they're sort of removed from it.
The key is whether australopiths & kin had halluces that could swivel outwardly while branch-walking and swivel inwardly while ground-walking.
stabilize a not-fully-developed terrestrial bipedal stance.
I presume that an "outward hallux" is a divergent hallux. That may differ from one that can swivel in or out per need. One that permanently stays divergent is a walking hazard, constantly snagging on vegetation, and would likely be selected
posteriorly cerebrum) and wide hips (Venus figurines?) and with Homo sapiens (software replaced mechanistic balancing, except in Khoisan and Andamaner females with very posterior buttocks (steatopygia), selected by long distance trekking.My understanding is the primitive hallux was anatomically similar to:~}
the pollex, in that it was opposable under voluntary muscular control. >> >> So an "outward" (your word) hallux would not have been an impediment
to walking on the ground. To the contrary, such a feature would be
advantageous to organisms which moved both terrestrially and
arboreally.
As you say, modern humans have shortened parallel toes, a derived
specialization for efficiently walking long distance on the ground.
Personally, I can with difficulty move my big toes only a little in
and out, like some crippled crab. However, I have a good friend who
can move her big toes substantially and strongly, enough to painfully
pinch other people's legs under the table while playing card games, to >> >> good strategic effect.
They
allow for arboreal behaviors when necessary but don't
harm the effectiveness of bipedality when the animal came down to the
ground.
*********************************************
Erika doesn't argue the cause for these arboreal aspects, but only >> >> >> >> that their presence in chimpanzees and gorillas inhibits efficient >> >> >> >> bipedality. Anybody who has seen videos of gorillas and chimpanzees
walking bipedally would agree they are much less efficient at it than
are humans. Erika's point in paraphrase is that Lucy had a big butt, I
cannot lie, and so walked more like humans do.
Consider my earlier point about Homo erectus: thick heavy femur and skull occiput mechanically improved balance and pace while ground-walking orthogonally; this continued with neanderthals with pronounced occipital bun (bone + enlarged
I wanted to go in depth on this video, but there is a massive noisy halloween celebration of trick or treating goblins and princesses here at the library. So enough.I hope you find time once the ghosts and goblins have gone.
On Sun, 6 Nov 2022 00:03:09 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
I'm from Minnesota, shod always but in bed or bath.<Full snip for focus>
As you say, modern humans have shortened parallel toes, a derived
specialization for efficiently walking long distance on the ground.
Personally, I can with difficulty move my big toes only a little in
and out, like some crippled crab. However, I have a good friend who
can move her big toes substantially and strongly, enough to painfully
pinch other people's legs under the table while playing card games, to
good strategic effect.
Our comfy confining cushioned shoes can cripple... this video short shows Barefoot shoes can return them to health. https://youtube.com/shorts/EOxOrxggBMI?feature=shareInteresting you mention that. She grew up in Hawaii when going around shoeless was common.
On Sat, 5 Nov 2022 20:05:10 -0700 (PDT), Daud Dedenbut that's different from palmigrady.
<daud....@gmail.com> wrote:
On Saturday, November 5, 2022 at 2:25:13 AM UTC-4, 69jp...@gmail.com wrote: >> On Fri, 4 Nov 2022 11:01:30 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Friday, November 4, 2022 at 2:21:56 AM UTC-4, 69jp...@gmail.com wrote:
On Thu, 3 Nov 2022 20:32:40 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Thursday, November 3, 2022 at 6:29:01 PM UTC-4, 69jp...@gmail.com wrote:My impression is there isn't enough evidence to show whether Pliocene >> >> African apes descended from Miocene European apes or Miocene African >> >> apes. Either way, there was enough time between the two eras to have >> >> evolved differences between either Miocene populations and Pliocene S. >> >> tchadensis.
On Thu, 3 Nov 2022 07:56:05 -0700 (PDT), Daud DedenYes, I claim it is *descended from* European Miocene apes of the Black Sea region.
<daud....@gmail.com> wrote:
On Tuesday, November 1, 2022 at 4:17:31 AM UTC-4, 69jp...@gmail.com wrote:Sahelanthropus tchadensis is neither Miocene nor European, but is a >> >> >> Pliocene central African species.
On Mon, 31 Oct 2022 15:15:01 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Monday, October 24, 2022 at 2:50:22 AM UTC-4, 69jp...@gmail.com wrote:
Gutsick Gibbon is the Youtube handle of a biological anthropology PhD-
student named Eriks. Two of her recent videos discuss some of the
latest developments relating to the origins of human bipedalism:
<https://www.youtube.com/watch?v=kbQAgPSHbZE>
The above is a link to a 32-minute video where Erika discusses several
papers relating to Sahelanthropus tchadensis. This fossil is >> >> >> >> >> remarkable in part because it's dated to about 7mya and was found in
central-african Chad, and also because it may be the oldest bipedal
hominin fossil found to date. However, there appears to be strong
disagreement whether the evidence supports bipedalism.
<https://www.youtube.com/watch?v=Nwkfkp360ps>
The above is a link to a 22-minute video where Erika discusses several
hypotheses about *why* our ancestors shifted to obligate bipedalism.
She discusses several hypotheses, and presents compelling arguments
for her preferred one.
Video by Erika on Lucy bipedalism: https://youtu.be/jo2ZLnucuHY >> >> >> >> Thank you for citing the above video. It's prelude to the ones I >> >> >> >> cited, and refers to them, and so complete a logical trilogy.
In another video, she says that Sahelanthropus was the LCA of Homo / Pan, (though probably just in the general sense). https://www.youtube.com/watch?v=g4FTbZLkpzU&t=7s
In my view, Sahelanthropus is just a southwestern European Miocene ape *Descendant*, very similar to their eastern and northern kin. I see nothing palmigrade in any Miocene ape.
I agree. I didn't mean all 'Pliocene African apes', only Sahelanthropus, but might include some others.
At 3:40 she talks about different modes of arboreal locomotion...she mentions "generalized miocene ape" & similar to "palmigrade pronograde arboreal quadrupeds of the miocene'.Erika says this:
To me, the European miocene apes were arboreal slow bimanual brachiating & slow upright bipedal walking on horizontal tree branches.
Is she referring to African miocene apes being pronograde palmigrade?
*********************************
Obviously australopithecus afarensis didn't evolve from a chimp but
from sort of generalized Miocene ape. But that being said, the >> >> >> >> morphology of modern chimpanzees is at least similar to some of our
palmigrade pronograde arboreal quadrupeds of the Miocene.
*********************************
So yes, Erika is saying at least some African Miocene apes were >> >> >> >> palmigrade aka foot parallel to the ground pronograde aka spine >> >> >> >> parallel to the ground, similar to modern chimpanzees.
Chimps aren't palmigrade, no extant ape is, all monkeys are obligatory palmigrade. Humans are palmigrade only during infancy while knee-crawling and bear-walking (I'd guess only within a dome shelter). Humans and chimps hold tools in hands,
the confusion, (my Bio background is more from botanical than zoological.). Some definitions are warranted.You seem to have mixed palmigrade with pronograde.
Please cite specifically where I seem to have done that.
Just look at your sentence immediately above the one you challenge.
Palmigrade is a scientific term to refer to locomotion with the whole >> >> foot on the ground, as with humans and apes when they walk bipedally. >> >> The feet of crawling infants are incidentally vertical to the ground >> >> aka not palmigrade, while their spine is nearly parallel to the ground >> >> aka pronograde.
Ok, my use of 'palmigrade' was in the palm-only sense, using plantigrade (sole) instead, since we normally refer to animals standing/walking on their feet, not their hands. I'll review things and adjust before responding, thanks for spotlighting
Yes. Knucklewalking doesn't afaik.My understanding is those terms apply equally to both forelimbs and hindlimbs.Yes, both can be noun or adjective as needed, -grade, -grady.Ok. I too am unfamiliar with the distinction between palmigrade and
Palmigrade Etymology
From Latin palma (“palm of the hand”) + gradi (“to walk”).
palmigrade
(zoology) Putting the whole foot upon the ground in walking, as some mammals do
https://wikidiff.com/plantigrade/palmigrade
https://en.m.wikipedia.org/wiki/Plantigrade
Plantigrade mammal species include (but are not limited to):
Some primates (including humans)
Ailuridae: red pandas
Ursidae: bears
plantigrade. One source I found said "palmigrade" is an adjective and
"plantigrade" is a noun, but that just adds to the confusion.
Anatomically, the relevant distinction is how much of the foot restsYes. Knucklewalking fits in-between, plantigrade hind limbs & digitigrade (dorsal) forelimbs.
on the ground when walking, either plantigrade, digitigrade or
unguligrade.
Thanks for the link. Are you familiar with a book called "ContestedFor primates, the importance of fingers as manipulating tools meansYes. Rainforest drills have shortish fingers, they walk on their fingertips not palms.
they necessarily compromise the hand's anatomy for locomotion. For
arboreal primates, the phalanges are curved to better grasp branches.
For quadruped primates, the hands may be flat on the ground as with
baboons. Facultative bipedal primates may use knuckle-walking as with
chimpanzees.
For obligate bipeds like genus homo, the hands aren't used forI liked this Sci Am article, especially near the end, section called Open Question.
locomotion at all, and their anatomy is devoted to manipulation. My
understanding is genus australopithecus are transitional between
arboreal bipedal primates and terrestrial bipedal primates.
https://www.scientificamerican.com/article/fossils-upend-conventional-wisdom-about-evolution-of-human-bipedalism/
Bones"? Erika does a multi-part and extremely detailed critique of
it.
against in a biped. Our toes have shortened, halluces converged, while our soles have lengthened providing postural stability.My understanding is, when Erika refers to bipedality withoutI don't know enough about Miocene apes to say if European and African
apes were different. My understanding is climate change caused >> >> >> >> European Miocene apes to go extinct before Australopiths evolved in
Africa, which suggests to me the two environments were different >> >> >> >> enough to support the differences you describe.
I opine that European Miocene apes expanded from the Black Sea region after the MSC, some of their descendants included australopiths, Homo etc. entering Africa in waves.
At 7:20, she apparently claims that chimp and gorilla arboreal traits interfere with their terrestrial locomotion "act to negate bipedalism" No, sleeping in bowl nests did that, selecting for short legs & backs.
https://youtu.be/jo2ZLnucuHY?t=451Erika says this:
*********************************************
Either way, the aspects that allow for arboriality found in
australopithecus afarensis are not the same types as the ones that we
find in chimpanzees and gorillas. In the latter two species, the >> >> >> >> arboreal aspects
I guess 'aspect' could include arboreal bowl nesting, I thought she meant arboreal locomotion only.
act to negate efficient bipedality,
Not arboreal hylobatids. Bowl sleeping in great apes shrank their leg, achilles & back length.
qualifiers, she means terrestrial bipedality.
Erika persuasively argues that an outward hallux would help towhereas in
australopithecus afarensis they're sort of removed from it.
The key is whether australopiths & kin had halluces that could swivel outwardly while branch-walking and swivel inwardly while ground-walking.
stabilize a not-fully-developed terrestrial bipedal stance.
I presume that an "outward hallux" is a divergent hallux. That may differ from one that can swivel in or out per need. One that permanently stays divergent is a walking hazard, constantly snagging on vegetation, and would likely be selected
posteriorly cerebrum) and wide hips (Venus figurines?) and with Homo sapiens (software replaced mechanistic balancing, except in Khoisan and Andamaner females with very posterior buttocks (steatopygia), selected by long distance trekking.My understanding is the primitive hallux was anatomically similar to >> >> the pollex, in that it was opposable under voluntary muscular control. >> >> So an "outward" (your word) hallux would not have been an impediment >> >> to walking on the ground. To the contrary, such a feature would be:~}
advantageous to organisms which moved both terrestrially and
arboreally.
As you say, modern humans have shortened parallel toes, a derived
specialization for efficiently walking long distance on the ground.
Personally, I can with difficulty move my big toes only a little in
and out, like some crippled crab. However, I have a good friend who
can move her big toes substantially and strongly, enough to painfully >> >> pinch other people's legs under the table while playing card games, to >> >> good strategic effect.
They
allow for arboreal behaviors when necessary but don't
harm the effectiveness of bipedality when the animal came down to the
ground.
*********************************************
Erika doesn't argue the cause for these arboreal aspects, but only
that their presence in chimpanzees and gorillas inhibits efficient
bipedality. Anybody who has seen videos of gorillas and chimpanzees
walking bipedally would agree they are much less efficient at it than
are humans. Erika's point in paraphrase is that Lucy had a big butt, I
cannot lie, and so walked more like humans do.
Consider my earlier point about Homo erectus: thick heavy femur and skull occiput mechanically improved balance and pace while ground-walking orthogonally; this continued with neanderthals with pronounced occipital bun (bone + enlarged
I wanted to go in depth on this video, but there is a massive noisy halloween celebration of trick or treating goblins and princesses here at the library. So enough.I hope you find time once the ghosts and goblins have gone.
On Thu, 3 Nov 2022 20:32:40 -0700 (PDT), Daud Deden
<daud.deden@gmail.com> wrote:
On Thursday, November 3, 2022 at 6:29:01 PM UTC-4, 69jp...@gmail.com wrote: >>> On Thu, 3 Nov 2022 07:56:05 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:Yes, I claim it is *descended from* European Miocene apes of the Black Sea region.
On Tuesday, November 1, 2022 at 4:17:31 AM UTC-4, 69jp...@gmail.com wrote:Sahelanthropus tchadensis is neither Miocene nor European, but is a
On Mon, 31 Oct 2022 15:15:01 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Monday, October 24, 2022 at 2:50:22 AM UTC-4, 69jp...@gmail.com wrote:Thank you for citing the above video. It's prelude to the ones I
Gutsick Gibbon is the Youtube handle of a biological anthropology PhD-
student named Eriks. Two of her recent videos discuss some of the >>> >> >> latest developments relating to the origins of human bipedalism:
<https://www.youtube.com/watch?v=kbQAgPSHbZE>
The above is a link to a 32-minute video where Erika discusses several
papers relating to Sahelanthropus tchadensis. This fossil is
remarkable in part because it's dated to about 7mya and was found in >>> >> >> central-african Chad, and also because it may be the oldest bipedal >>> >> >> hominin fossil found to date. However, there appears to be strong >>> >> >> disagreement whether the evidence supports bipedalism.
<https://www.youtube.com/watch?v=Nwkfkp360ps>
The above is a link to a 22-minute video where Erika discusses several
hypotheses about *why* our ancestors shifted to obligate bipedalism. >>> >> >> She discusses several hypotheses, and presents compelling arguments >>> >> >> for her preferred one.
Video by Erika on Lucy bipedalism: https://youtu.be/jo2ZLnucuHY
cited, and refers to them, and so complete a logical trilogy.
In another video, she says that Sahelanthropus was the LCA of Homo / Pan, (though probably just in the general sense). https://www.youtube.com/watch?v=g4FTbZLkpzU&t=7s
In my view, Sahelanthropus is just a southwestern European Miocene ape *Descendant*, very similar to their eastern and northern kin. I see nothing palmigrade in any Miocene ape.
Pliocene central African species.
My impression is there isn't enough evidence to show whether Pliocene
African apes descended from Miocene European apes or Miocene African
apes. Either way, there was enough time between the two eras to have
evolved differences between either Miocene populations and Pliocene S. >tchadensis.
On Fri, 04 Nov 2022 02:21:55 -0400, jillery <69jp...@gmail.com>
wrote:
On Thu, 3 Nov 2022 20:32:40 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Thursday, November 3, 2022 at 6:29:01 PM UTC-4, 69jp...@gmail.com wrote:
On Thu, 3 Nov 2022 07:56:05 -0700 (PDT), Daud DedenYes, I claim it is *descended from* European Miocene apes of the Black Sea region.
<daud....@gmail.com> wrote:
On Tuesday, November 1, 2022 at 4:17:31 AM UTC-4, 69jp...@gmail.com wrote:Sahelanthropus tchadensis is neither Miocene nor European, but is a
On Mon, 31 Oct 2022 15:15:01 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Monday, October 24, 2022 at 2:50:22 AM UTC-4, 69jp...@gmail.com wrote:Thank you for citing the above video. It's prelude to the ones I
Gutsick Gibbon is the Youtube handle of a biological anthropology PhD-
student named Eriks. Two of her recent videos discuss some of the >>> >> >> latest developments relating to the origins of human bipedalism: >>> >> >>
<https://www.youtube.com/watch?v=kbQAgPSHbZE>
The above is a link to a 32-minute video where Erika discusses several
papers relating to Sahelanthropus tchadensis. This fossil is
remarkable in part because it's dated to about 7mya and was found in
central-african Chad, and also because it may be the oldest bipedal
hominin fossil found to date. However, there appears to be strong >>> >> >> disagreement whether the evidence supports bipedalism.
<https://www.youtube.com/watch?v=Nwkfkp360ps>
The above is a link to a 22-minute video where Erika discusses several
hypotheses about *why* our ancestors shifted to obligate bipedalism.
She discusses several hypotheses, and presents compelling arguments
for her preferred one.
Video by Erika on Lucy bipedalism: https://youtu.be/jo2ZLnucuHY
cited, and refers to them, and so complete a logical trilogy.
In another video, she says that Sahelanthropus was the LCA of Homo / Pan, (though probably just in the general sense). https://www.youtube.com/watch?v=g4FTbZLkpzU&t=7s
In my view, Sahelanthropus is just a southwestern European Miocene ape *Descendant*, very similar to their eastern and northern kin. I see nothing palmigrade in any Miocene ape.
Pliocene central African species.
My impression is there isn't enough evidence to show whether Pliocene >African apes descended from Miocene European apes or Miocene AfricanI have recently become aware of:
apes. Either way, there was enough time between the two eras to have >evolved differences between either Miocene populations and Pliocene S. >tchadensis.
<https://en.wikipedia.org/wiki/Danuvius_guggenmosi>
which was a Miocene European ape that may have evolved arboreal
bipedalism similar to S.tchadensis.
Depending on how widespread its range, and how successful its
descendants, it's plausible they lived south of the Black Sea during
the late Miocene.
The question then becomes whether it's more likely these apes found
their way into Africa to become the ancestors of Pliocene
S.tchadensis, or whether S.tchadensis evolved from Miocene African
apes.
Unfortunately, the habitat of these apes made their fossil
preservation extremely rare, and so the evidence to well support
either hypothesis is lacking.
However, the question at least conditionally can be answered by
comparing the likelihood of a migratory pathway during that time,
versus the likelihood of arboreal bipedalism evolving independently in
two populations.
There are a number of anatomic features associated with arboreal
bipedalism, some of which are necessary, ex. anterior foramen magnum,
and some of which are incidental, ex. molar patterns. Descendant
populations are more likely to share these features than are
independent populations. This suggests to me that a sufficiently
robust fossil record could answer this question with some degree of certainty.
Alternately, my understanding is southern Europe and central Africa
are ecological opposites, in the sense that when one is hot and dry
the other is temperate and wet.
Miocene. This suggests to me there could not have been an unbroken
forested path for arboreal apes to migrate between Europe/Near East
and Central Africa.
On Wednesday, November 16, 2022 at 11:08:11 AM UTC-5, 69jp...@gmail.com wrote:
On Fri, 04 Nov 2022 02:21:55 -0400, jillery <69jp...@gmail.com>
wrote:
On Thu, 3 Nov 2022 20:32:40 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Thursday, November 3, 2022 at 6:29:01 PM UTC-4, 69jp...@gmail.com wrote:
On Thu, 3 Nov 2022 07:56:05 -0700 (PDT), Daud DedenYes, I claim it is *descended from* European Miocene apes of the Black Sea region.
<daud....@gmail.com> wrote:
On Tuesday, November 1, 2022 at 4:17:31 AM UTC-4, 69jp...@gmail.com wrote:Sahelanthropus tchadensis is neither Miocene nor European, but is a >>> Pliocene central African species.
On Mon, 31 Oct 2022 15:15:01 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Monday, October 24, 2022 at 2:50:22 AM UTC-4, 69jp...@gmail.com wrote:
Gutsick Gibbon is the Youtube handle of a biological anthropology PhD-
student named Eriks. Two of her recent videos discuss some of the
latest developments relating to the origins of human bipedalism: >>> >> >>
<https://www.youtube.com/watch?v=kbQAgPSHbZE>
The above is a link to a 32-minute video where Erika discusses several
papers relating to Sahelanthropus tchadensis. This fossil is
remarkable in part because it's dated to about 7mya and was found in
central-african Chad, and also because it may be the oldest bipedal
hominin fossil found to date. However, there appears to be strong
disagreement whether the evidence supports bipedalism.
<https://www.youtube.com/watch?v=Nwkfkp360ps>
The above is a link to a 22-minute video where Erika discusses several
hypotheses about *why* our ancestors shifted to obligate bipedalism.
She discusses several hypotheses, and presents compelling arguments
for her preferred one.
Video by Erika on Lucy bipedalism: https://youtu.be/jo2ZLnucuHY >>> >> Thank you for citing the above video. It's prelude to the ones I >>> >> cited, and refers to them, and so complete a logical trilogy.
In another video, she says that Sahelanthropus was the LCA of Homo / Pan, (though probably just in the general sense). https://www.youtube.com/watch?v=g4FTbZLkpzU&t=7s
In my view, Sahelanthropus is just a southwestern European Miocene ape *Descendant*, very similar to their eastern and northern kin. I see nothing palmigrade in any Miocene ape.
cooking (fish .78ma) and earliest waternut gathering and bread making. The region is amenable to hominins & Homo.My impression is there isn't enough evidence to show whether Pliocene >African apes descended from Miocene European apes or Miocene African >apes. Either way, there was enough time between the two eras to have >evolved differences between either Miocene populations and Pliocene S. >tchadensis.I have recently become aware of:
<https://en.wikipedia.org/wiki/Danuvius_guggenmosi>
which was a Miocene European ape that may have evolved arboreal
bipedalism similar to S.tchadensis.
Depending on how widespread its range, and how successful its
descendants, it's plausible they lived south of the Black Sea during
the late Miocene.
The question then becomes whether it's more likely these apes found
their way into Africa to become the ancestors of Pliocene
S.tchadensis, or whether S.tchadensis evolved from Miocene African
apes.
Unfortunately, the habitat of these apes made their fossil
preservation extremely rare, and so the evidence to well support
either hypothesis is lacking.
However, the question at least conditionally can be answered by
comparing the likelihood of a migratory pathway during that time,
versus the likelihood of arboreal bipedalism evolving independently in
two populations.
There are a number of anatomic features associated with arboreal bipedalism, some of which are necessary, ex. anterior foramen magnum,4
The foramen magnum is always situated relatively more anteriorly in immature than in mature apes and men.
and some of which are incidental, ex. molar patterns. Descendant populations are more likely to share these features than are
independent populations. This suggests to me that a sufficiently
robust fossil record could answer this question with some degree of certainty.
Alternately, my understanding is southern Europe and central AfricaCentral Africa is and was hot, the southern Black Sea is between temperate and tropical.
are ecological opposites, in the sense that when one is hot and dry
the other is temperate and wet.
This is as true now as it was in the
Miocene. This suggests to me there could not have been an unbroken forested path for arboreal apes to migrate between Europe/Near EastI would not claim nor disclaim that. The Levant is near the midpoint, extends the African Rift valley to Anatolia, is a major avian migration route between Africa and Eurasia, has fossil/artifacts of Homo erectus, neanderthal & sapiens oldest known
and Central Africa.
Danuvius, Rudapithecus, Graecopithecus, Oranopithecus each had a unique trait shared with hominins. I think of them as a superspecies with local variations.-
On Thursday, November 17, 2022 at 1:29:04 AM UTC-5, Daud Deden wrote:
On Wednesday, November 16, 2022 at 11:08:11 AM UTC-5, 69jp...@gmail.com wrote:
On Fri, 04 Nov 2022 02:21:55 -0400, jillery <69jp...@gmail.com>
wrote:
On Thu, 3 Nov 2022 20:32:40 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Thursday, November 3, 2022 at 6:29:01 PM UTC-4, 69jp...@gmail.com wrote:
On Thu, 3 Nov 2022 07:56:05 -0700 (PDT), Daud DedenYes, I claim it is *descended from* European Miocene apes of the Black Sea region.
<daud....@gmail.com> wrote:
On Tuesday, November 1, 2022 at 4:17:31 AM UTC-4, 69jp...@gmail.com wrote:Sahelanthropus tchadensis is neither Miocene nor European, but is a >> > >>> Pliocene central African species.
On Mon, 31 Oct 2022 15:15:01 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Monday, October 24, 2022 at 2:50:22 AM UTC-4, 69jp...@gmail.com wrote:
Gutsick Gibbon is the Youtube handle of a biological anthropology PhD-
student named Eriks. Two of her recent videos discuss some of the
latest developments relating to the origins of human bipedalism:
<https://www.youtube.com/watch?v=kbQAgPSHbZE>
The above is a link to a 32-minute video where Erika discusses several
papers relating to Sahelanthropus tchadensis. This fossil is
remarkable in part because it's dated to about 7mya and was found in
central-african Chad, and also because it may be the oldest bipedal
hominin fossil found to date. However, there appears to be strong
disagreement whether the evidence supports bipedalism.
<https://www.youtube.com/watch?v=Nwkfkp360ps>
The above is a link to a 22-minute video where Erika discusses several
hypotheses about *why* our ancestors shifted to obligate bipedalism.
She discusses several hypotheses, and presents compelling arguments
for her preferred one.
Video by Erika on Lucy bipedalism: https://youtu.be/jo2ZLnucuHY >> > >>> >> Thank you for citing the above video. It's prelude to the ones I >> > >>> >> cited, and refers to them, and so complete a logical trilogy.
In another video, she says that Sahelanthropus was the LCA of Homo / Pan, (though probably just in the general sense). https://www.youtube.com/watch?v=g4FTbZLkpzU&t=7s
In my view, Sahelanthropus is just a southwestern European Miocene ape *Descendant*, very similar to their eastern and northern kin. I see nothing palmigrade in any Miocene ape.
My impression is there isn't enough evidence to show whether Pliocene
African apes descended from Miocene European apes or Miocene African
apes. Either way, there was enough time between the two eras to have
evolved differences between either Miocene populations and Pliocene S. >> > >tchadensis.
I have recently become aware of:
<https://en.wikipedia.org/wiki/Danuvius_guggenmosi>
which was a Miocene European ape that may have evolved arboreal
bipedalism similar to S.tchadensis.
Depending on how widespread its range, and how successful its
descendants, it's plausible they lived south of the Black Sea during
the late Miocene.
The question then becomes whether it's more likely these apes found
their way into Africa to become the ancestors of Pliocene
S.tchadensis, or whether S.tchadensis evolved from Miocene African
apes.
Unfortunately, the habitat of these apes made their fossil
preservation extremely rare, and so the evidence to well support
either hypothesis is lacking.
However, the question at least conditionally can be answered by
comparing the likelihood of a migratory pathway during that time,
versus the likelihood of arboreal bipedalism evolving independently in
two populations.
There are a number of anatomic features associated with arboreal
bipedalism, some of which are necessary, ex. anterior foramen magnum,
The foramen magnum is always situated relatively more anteriorly in immature than in mature apes and men.
and some of which are incidental, ex. molar patterns. DescendantCentral Africa is and was hot,
populations are more likely to share these features than are
independent populations. This suggests to me that a sufficiently
robust fossil record could answer this question with some degree of
certainty.
Alternately, my understanding is southern Europe and central Africa
are ecological opposites, in the sense that when one is hot and dry
the other is temperate and wet.
the southern Black Sea is between temperate and tropical.
cooking (fish .78ma) and earliest waternut gathering and bread making. The region is amenable to hominins & Homo.This is as true now as it was in theI would not claim nor disclaim that. The Levant is near the midpoint, extends the African Rift valley to Anatolia, is a major avian migration route between Africa and Eurasia, has fossil/artifacts of Homo erectus, neanderthal & sapiens oldest known
Miocene. This suggests to me there could not have been an unbroken
forested path for arboreal apes to migrate between Europe/Near East
and Central Africa.
This may have caused lordosis (the normal curvature of the human spine) and moved the center of mass over the hips and legs, which implies some habitual bipedal activity.Danuvius, Rudapithecus, Graecopithecus, Oranopithecus each had a unique trait shared with hominins. I think of them as a superspecies with local variations.-
If you place Danuvius half-way between fast brachiating bipedal long backed long achilles tendon hylobatids and bipedal Homo with long back and long achilles tendon, it fits perfectly.
Wiki:
Danuvius is thought to have had a broad chest. It is the first recorded Miocene great ape to have had the diaphragm located in the lower chest cavity, as in Homo, indicating an extended lower back and a greater number of functional lumbar vertebrae.
The robust finger and hypertrophied wrist and elbow bones indicate a strong grip and load bearing adaptations for the arms. The legs also show adaptations for load-bearing, especially at the hypertrophied knee joint. There was likely limited ankleloading, and the ankle would have had a hinge-like function, being most stable if positioned perpendicularly to the leg as opposed to at an angle in apes. Danuvius was likely able to achieve a strong grip with its big toes, unlike modern African great
On Wed, 16 Nov 2022 22:42:03 -0800 (PST), Daud Deden
<daud....@gmail.com> wrote:
On Thursday, November 17, 2022 at 1:29:04 AM UTC-5, Daud Deden wrote:Not sure what you mean by "mature"; the individual or the species?
On Wednesday, November 16, 2022 at 11:08:11 AM UTC-5, 69jp...@gmail.com wrote:
On Fri, 04 Nov 2022 02:21:55 -0400, jillery <69jp...@gmail.com>The foramen magnum is always situated relatively more anteriorly in immature than in mature apes and men.
wrote:
On Thu, 3 Nov 2022 20:32:40 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Thursday, November 3, 2022 at 6:29:01 PM UTC-4, 69jp...@gmail.com wrote:
On Thu, 3 Nov 2022 07:56:05 -0700 (PDT), Daud DedenYes, I claim it is *descended from* European Miocene apes of the Black Sea region.
<daud....@gmail.com> wrote:
On Tuesday, November 1, 2022 at 4:17:31 AM UTC-4, 69jp...@gmail.com wrote:Sahelanthropus tchadensis is neither Miocene nor European, but is a >> > >>> Pliocene central African species.
On Mon, 31 Oct 2022 15:15:01 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Monday, October 24, 2022 at 2:50:22 AM UTC-4, 69jp...@gmail.com wrote:
Gutsick Gibbon is the Youtube handle of a biological anthropology PhD-
student named Eriks. Two of her recent videos discuss some of the
latest developments relating to the origins of human bipedalism:
<https://www.youtube.com/watch?v=kbQAgPSHbZE>
The above is a link to a 32-minute video where Erika discusses several
papers relating to Sahelanthropus tchadensis. This fossil is >> > >>> >> >> remarkable in part because it's dated to about 7mya and was found in
central-african Chad, and also because it may be the oldest bipedal
hominin fossil found to date. However, there appears to be strong
disagreement whether the evidence supports bipedalism.
<https://www.youtube.com/watch?v=Nwkfkp360ps>
The above is a link to a 22-minute video where Erika discusses several
hypotheses about *why* our ancestors shifted to obligate bipedalism.
She discusses several hypotheses, and presents compelling arguments
for her preferred one.
Video by Erika on Lucy bipedalism: https://youtu.be/jo2ZLnucuHY >> > >>> >> Thank you for citing the above video. It's prelude to the ones I >> > >>> >> cited, and refers to them, and so complete a logical trilogy.
In another video, she says that Sahelanthropus was the LCA of Homo / Pan, (though probably just in the general sense). https://www.youtube.com/watch?v=g4FTbZLkpzU&t=7s
In my view, Sahelanthropus is just a southwestern European Miocene ape *Descendant*, very similar to their eastern and northern kin. I see nothing palmigrade in any Miocene ape.
My impression is there isn't enough evidence to show whether Pliocene >> > >African apes descended from Miocene European apes or Miocene African >> > >apes. Either way, there was enough time between the two eras to have >> > >evolved differences between either Miocene populations and Pliocene S. >> > >tchadensis.
I have recently become aware of:
<https://en.wikipedia.org/wiki/Danuvius_guggenmosi>
which was a Miocene European ape that may have evolved arboreal
bipedalism similar to S.tchadensis.
Depending on how widespread its range, and how successful its
descendants, it's plausible they lived south of the Black Sea during
the late Miocene.
The question then becomes whether it's more likely these apes found
their way into Africa to become the ancestors of Pliocene
S.tchadensis, or whether S.tchadensis evolved from Miocene African
apes.
Unfortunately, the habitat of these apes made their fossil
preservation extremely rare, and so the evidence to well support
either hypothesis is lacking.
However, the question at least conditionally can be answered by
comparing the likelihood of a migratory pathway during that time,
versus the likelihood of arboreal bipedalism evolving independently in >> > two populations.
There are a number of anatomic features associated with arboreal
bipedalism, some of which are necessary, ex. anterior foramen magnum, >>
Either way, the important point is the position and angle of foramen
magnum are diagnostic among all vertebrates for how they habitually
hold their head, and so includes/excludes bipedalism among hominids.
... and wet aka tropical,and some of which are incidental, ex. molar patterns. DescendantCentral Africa is and was hot,
populations are more likely to share these features than are
independent populations. This suggests to me that a sufficiently
robust fossil record could answer this question with some degree of
certainty.
Alternately, my understanding is southern Europe and central Africa
are ecological opposites, in the sense that when one is hot and dry
the other is temperate and wet.
bipedal arboreal apes.
the southern Black Sea is between temperate and tropical.Correct. Southern Europe and the Black Sea are at the same latitudes.
This suggests they would tend to have the same climate. However, the
Black Sea is farther inland, and so suffers more continental extremes.
So any climate changes will appear first around the Black Sea and
become more extreme compared to southern Europe.
Moving toward 30 degrees latitude, rainfall becomes seasonally dry,
and then almost continuously dry. My understanding is, the only
native forests south of the Caspian are in the mountains, and adjacent
to the Mediterranean coasts. Arboreal apes of any kind would find
these deserts impassible.
To a first approximation, average rainfall and temperature are
functions of latitude. However, while temperature is a function of
the sine of latitude, rainfall is more complex. It tends to be
continuously heavy near the equator, continuously dry near 30 degrees,
and seasonally variable between 30 and 60 degrees. This general
pattern is modified, sometimes dramatically, by terrain, ocean
currents, seasons, and Milankovitch cycles.
The most significant variable is Africa's northward tectonic
migration, about a centimeter a year since before the Miocene. So,
while central Africa has moved from south to north of the equator with little effect, north Africa has approached and then went north of 30 degrees, making it over time ever drier, amplifying other climate
trends, making once wooded areas into vast savannah and desert.
Also, Africa's tectonic slide north almost certainly pinched closedcooking (fish .78ma) and earliest waternut gathering and bread making. The region is amenable to hominins & Homo.
the Gilbraltar Sttraits, which caused the Mediterranean to dry up at
least once, and likely several times as sea levels rose and fell. The resulting hot salt basin would also have been impassible for arboreal
apes.
This is as true now as it was in theI would not claim nor disclaim that. The Levant is near the midpoint, extends the African Rift valley to Anatolia, is a major avian migration route between Africa and Eurasia, has fossil/artifacts of Homo erectus, neanderthal & sapiens oldest known
Miocene. This suggests to me there could not have been an unbroken
forested path for arboreal apes to migrate between Europe/Near East
and Central Africa.
I acknowledge the facts you describe above. However, the Levant is
savannah and desert except for a narrow strip along the Mediterranean
and up in the mountains. While this is no problem for terrestrial
bipeds like Homo, ISTM arboreal hominids like D.guggenmosi would have
a much harder time living/migrating there.
This may have caused lordosis (the normal curvature of the human spine) and moved the center of mass over the hips and legs, which implies some habitual bipedal activity.Danuvius, Rudapithecus, Graecopithecus, Oranopithecus each had a unique trait shared with hominins. I think of them as a superspecies with local variations.-
If you place Danuvius half-way between fast brachiating bipedal long backed long achilles tendon hylobatids and bipedal Homo with long back and long achilles tendon, it fits perfectly.
Wiki:
Danuvius is thought to have had a broad chest. It is the first recorded Miocene great ape to have had the diaphragm located in the lower chest cavity, as in Homo, indicating an extended lower back and a greater number of functional lumbar vertebrae.
loading, and the ankle would have had a hinge-like function, being most stable if positioned perpendicularly to the leg as opposed to at an angle in apes. Danuvius was likely able to achieve a strong grip with its big toes, unlike modern African greatThe robust finger and hypertrophied wrist and elbow bones indicate a strong grip and load bearing adaptations for the arms. The legs also show adaptations for load-bearing, especially at the hypertrophied knee joint. There was likely limited ankle
On Thursday, November 17, 2022 at 12:57:57 PM UTC-5, 69jp...@gmail.com wrote:known cooking (fish .78ma) and earliest waternut gathering and bread making. The region is amenable to hominins & Homo.
On Wed, 16 Nov 2022 22:42:03 -0800 (PST), Daud Deden
<daud....@gmail.com> wrote:
Individually.On Thursday, November 17, 2022 at 1:29:04 AM UTC-5, Daud Deden wrote:Not sure what you mean by "mature"; the individual or the species?
On Wednesday, November 16, 2022 at 11:08:11 AM UTC-5, 69jp...@gmail.com wrote:
On Fri, 04 Nov 2022 02:21:55 -0400, jillery <69jp...@gmail.com>The foramen magnum is always situated relatively more anteriorly in immature than in mature apes and men.
wrote:
On Thu, 3 Nov 2022 20:32:40 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Thursday, November 3, 2022 at 6:29:01 PM UTC-4, 69jp...@gmail.com wrote:
On Thu, 3 Nov 2022 07:56:05 -0700 (PDT), Daud DedenYes, I claim it is *descended from* European Miocene apes of the Black Sea region.
<daud....@gmail.com> wrote:
On Tuesday, November 1, 2022 at 4:17:31 AM UTC-4, 69jp...@gmail.com wrote:Sahelanthropus tchadensis is neither Miocene nor European, but is a
On Mon, 31 Oct 2022 15:15:01 -0700 (PDT), Daud DedenIn another video, she says that Sahelanthropus was the LCA of Homo / Pan, (though probably just in the general sense). https://www.youtube.com/watch?v=g4FTbZLkpzU&t=7s
<daud....@gmail.com> wrote:
On Monday, October 24, 2022 at 2:50:22 AM UTC-4, 69jp...@gmail.com wrote:Thank you for citing the above video. It's prelude to the ones I
Gutsick Gibbon is the Youtube handle of a biological anthropology PhD-
student named Eriks. Two of her recent videos discuss some of the
latest developments relating to the origins of human bipedalism:
<https://www.youtube.com/watch?v=kbQAgPSHbZE>
The above is a link to a 32-minute video where Erika discusses several
papers relating to Sahelanthropus tchadensis. This fossil is
remarkable in part because it's dated to about 7mya and was found in
central-african Chad, and also because it may be the oldest bipedal
hominin fossil found to date. However, there appears to be strong
disagreement whether the evidence supports bipedalism.
<https://www.youtube.com/watch?v=Nwkfkp360ps>
The above is a link to a 22-minute video where Erika discusses several
hypotheses about *why* our ancestors shifted to obligate bipedalism.
She discusses several hypotheses, and presents compelling arguments
for her preferred one.
Video by Erika on Lucy bipedalism: https://youtu.be/jo2ZLnucuHY
cited, and refers to them, and so complete a logical trilogy. >> > >>> >
In my view, Sahelanthropus is just a southwestern European Miocene ape *Descendant*, very similar to their eastern and northern kin. I see nothing palmigrade in any Miocene ape.
Pliocene central African species.
My impression is there isn't enough evidence to show whether Pliocene
African apes descended from Miocene European apes or Miocene African >> > >apes. Either way, there was enough time between the two eras to have >> > >evolved differences between either Miocene populations and Pliocene S.
tchadensis.
I have recently become aware of:
<https://en.wikipedia.org/wiki/Danuvius_guggenmosi>
which was a Miocene European ape that may have evolved arboreal
bipedalism similar to S.tchadensis.
Depending on how widespread its range, and how successful its
descendants, it's plausible they lived south of the Black Sea during >> > the late Miocene.
The question then becomes whether it's more likely these apes found >> > their way into Africa to become the ancestors of Pliocene
S.tchadensis, or whether S.tchadensis evolved from Miocene African
apes.
Unfortunately, the habitat of these apes made their fossil
preservation extremely rare, and so the evidence to well support
either hypothesis is lacking.
However, the question at least conditionally can be answered by
comparing the likelihood of a migratory pathway during that time,
versus the likelihood of arboreal bipedalism evolving independently in
two populations.
There are a number of anatomic features associated with arboreal
bipedalism, some of which are necessary, ex. anterior foramen magnum, >>
Either way, the important point is the position and angle of foramen magnum are diagnostic among all vertebrates for how they habituallyYes, but no. Great apes are bipedal except when (hurrying) on open ground they adopt quadrupedalism. Homo retains the primitive bipedal gait of hominoid ancestors, as do hylobatids.
hold their head, and so includes/excludes bipedalism among hominids.
The adoption of qpal knucklewalking by African apes indicates that their ancient habitat went through a dry phase (rainforest became patchy) forcing a terrestrial dog-like gait.... and wet aka tropical,and some of which are incidental, ex. molar patterns. DescendantCentral Africa is and was hot,
populations are more likely to share these features than are
independent populations. This suggests to me that a sufficiently
robust fossil record could answer this question with some degree of >> > certainty.
Alternately, my understanding is southern Europe and central Africa >> > are ecological opposites, in the sense that when one is hot and dry >> > the other is temperate and wet.
just right for the evolution of small
bipedal arboreal apes.The fact that there are no small bipedal arboreal apes in Africa indicates that there was some climate shifting.
I'm talking about from 11ma through the MSC to 5ma. The Medit. & Red Seas dried out, the Black Sea didn't.the southern Black Sea is between temperate and tropical.Correct. Southern Europe and the Black Sea are at the same latitudes.
This suggests they would tend to have the same climate. However, the
Black Sea is farther inland, and so suffers more continental extremes.
So any climate changes will appear first around the Black Sea and
become more extreme compared to southern Europe.
Moving toward 30 degrees latitude, rainfall becomes seasonally dry,You are speaking of recent climate. There are no arboreal apes there now.
and then almost continuously dry. My understanding is, the only
native forests south of the Caspian are in the mountains, and adjacent
to the Mediterranean coasts. Arboreal apes of any kind would find
these deserts impassible.
To a first approximation, average rainfall and temperature are
functions of latitude. However, while temperature is a function of
the sine of latitude, rainfall is more complex. It tends to be continuously heavy near the equator, continuously dry near 30 degrees,
and seasonally variable between 30 and 60 degrees. This general
pattern is modified, sometimes dramatically, by terrain, ocean
currents, seasons, and Milankovitch cycles.
The most significant variable is Africa's northward tectonicYes.
migration, about a centimeter a year since before the Miocene. So,
while central Africa has moved from south to north of the equator with little effect, north Africa has approached and then went north of 30 degrees, making it over time ever drier, amplifying other climate
trends, making once wooded areas into vast savannah and desert.
Also, Africa's tectonic slide north almost certainly pinched closed
the Gilbraltar Sttraits, which caused the Mediterranean to dry up at
least once, and likely several times as sea levels rose and fell. The resulting hot salt basin would also have been impassible for arboreal apes.
This is as true now as it was in theI would not claim nor disclaim that. The Levant is near the midpoint, extends the African Rift valley to Anatolia, is a major avian migration route between Africa and Eurasia, has fossil/artifacts of Homo erectus, neanderthal & sapiens oldest
Miocene. This suggests to me there could not have been an unbroken
forested path for arboreal apes to migrate between Europe/Near East >> > and Central Africa.
This may have caused lordosis (the normal curvature of the human spine) and moved the center of mass over the hips and legs, which implies some habitual bipedal activity.I acknowledge the facts you describe above. However, the Levant is savannah and desert except for a narrow strip along the Mediterranean"is". Again, refer to microclimate of Levant 11ma - 5ma. Today's Dead Sea was once the vast brackish Lake Lisan that reached to Lebanon, a gallery forest may have reached from Anatolia to Egypt.
and up in the mountains. While this is no problem for terrestrial
bipeds like Homo, ISTM arboreal hominids like D.guggenmosi would have
a much harder time living/migrating there.
What is ISTM?
Danuvius, Rudapithecus, Graecopithecus, Oranopithecus each had a unique trait shared with hominins. I think of them as a superspecies with local variations.-
If you place Danuvius half-way between fast brachiating bipedal long backed long achilles tendon hylobatids and bipedal Homo with long back and long achilles tendon, it fits perfectly.
Wiki:
Danuvius is thought to have had a broad chest. It is the first recorded Miocene great ape to have had the diaphragm located in the lower chest cavity, as in Homo, indicating an extended lower back and a greater number of functional lumbar vertebrae.
loading, and the ankle would have had a hinge-like function, being most stable if positioned perpendicularly to the leg as opposed to at an angle in apes. Danuvius was likely able to achieve a strong grip with its big toes, unlike modern African greatThe robust finger and hypertrophied wrist and elbow bones indicate a strong grip and load bearing adaptations for the arms. The legs also show adaptations for load-bearing, especially at the hypertrophied knee joint. There was likely limited ankle
On Thursday, November 17, 2022 at 12:57:57 PM UTC-5, 69jp...@gmail.com wrote: >> On Wed, 16 Nov 2022 22:42:03 -0800 (PST), Daud Deden
<daud....@gmail.com> wrote:
On Thursday, November 17, 2022 at 1:29:04 AM UTC-5, Daud Deden wrote:Not sure what you mean by "mature"; the individual or the species?
On Wednesday, November 16, 2022 at 11:08:11 AM UTC-5, 69jp...@gmail.com wrote:
On Fri, 04 Nov 2022 02:21:55 -0400, jillery <69jp...@gmail.com>The foramen magnum is always situated relatively more anteriorly in immature than in mature apes and men.
wrote:
On Thu, 3 Nov 2022 20:32:40 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Thursday, November 3, 2022 at 6:29:01 PM UTC-4, 69jp...@gmail.com wrote:
On Thu, 3 Nov 2022 07:56:05 -0700 (PDT), Daud DedenYes, I claim it is *descended from* European Miocene apes of the Black Sea region.
<daud....@gmail.com> wrote:
On Tuesday, November 1, 2022 at 4:17:31 AM UTC-4, 69jp...@gmail.com wrote:Sahelanthropus tchadensis is neither Miocene nor European, but is a
On Mon, 31 Oct 2022 15:15:01 -0700 (PDT), Daud DedenIn another video, she says that Sahelanthropus was the LCA of Homo / Pan, (though probably just in the general sense). https://www.youtube.com/watch?v=g4FTbZLkpzU&t=7s
<daud....@gmail.com> wrote:
On Monday, October 24, 2022 at 2:50:22 AM UTC-4, 69jp...@gmail.com wrote:Thank you for citing the above video. It's prelude to the ones I
Gutsick Gibbon is the Youtube handle of a biological anthropology PhD-
student named Eriks. Two of her recent videos discuss some of the
latest developments relating to the origins of human bipedalism:
<https://www.youtube.com/watch?v=kbQAgPSHbZE>
The above is a link to a 32-minute video where Erika discusses several
papers relating to Sahelanthropus tchadensis. This fossil is >> >> > >>> >> >> remarkable in part because it's dated to about 7mya and was found in
central-african Chad, and also because it may be the oldest bipedal
hominin fossil found to date. However, there appears to be strong
disagreement whether the evidence supports bipedalism.
<https://www.youtube.com/watch?v=Nwkfkp360ps>
The above is a link to a 22-minute video where Erika discusses several
hypotheses about *why* our ancestors shifted to obligate bipedalism.
She discusses several hypotheses, and presents compelling arguments
for her preferred one.
Video by Erika on Lucy bipedalism: https://youtu.be/jo2ZLnucuHY
cited, and refers to them, and so complete a logical trilogy. >> >> > >>> >
In my view, Sahelanthropus is just a southwestern European Miocene ape *Descendant*, very similar to their eastern and northern kin. I see nothing palmigrade in any Miocene ape.
Pliocene central African species.
My impression is there isn't enough evidence to show whether Pliocene >> >> > >African apes descended from Miocene European apes or Miocene African >> >> > >apes. Either way, there was enough time between the two eras to have >> >> > >evolved differences between either Miocene populations and Pliocene S.
tchadensis.
I have recently become aware of:
<https://en.wikipedia.org/wiki/Danuvius_guggenmosi>
which was a Miocene European ape that may have evolved arboreal
bipedalism similar to S.tchadensis.
Depending on how widespread its range, and how successful its
descendants, it's plausible they lived south of the Black Sea during >> >> > the late Miocene.
The question then becomes whether it's more likely these apes found
their way into Africa to become the ancestors of Pliocene
S.tchadensis, or whether S.tchadensis evolved from Miocene African
apes.
Unfortunately, the habitat of these apes made their fossil
preservation extremely rare, and so the evidence to well support
either hypothesis is lacking.
However, the question at least conditionally can be answered by
comparing the likelihood of a migratory pathway during that time,
versus the likelihood of arboreal bipedalism evolving independently in >> >> > two populations.
There are a number of anatomic features associated with arboreal
bipedalism, some of which are necessary, ex. anterior foramen magnum, >> >>
Individually.
Either way, the important point is the position and angle of foramen
magnum are diagnostic among all vertebrates for how they habitually
hold their head, and so includes/excludes bipedalism among hominids.
Yes, but no. Great apes are bipedal except when (hurrying) on open ground they adopt quadrupedalism. Homo retains the primitive bipedal gait of hominoid ancestors, as do hylobatids.
... and wet aka tropical,and some of which are incidental, ex. molar patterns. DescendantCentral Africa is and was hot,
populations are more likely to share these features than are
independent populations. This suggests to me that a sufficiently
robust fossil record could answer this question with some degree of
certainty.
Alternately, my understanding is southern Europe and central Africa
are ecological opposites, in the sense that when one is hot and dry
the other is temperate and wet.
The adoption of qpal knucklewalking by African apes indicates that their ancient habitat went through a dry phase (rainforest became patchy) forcing a terrestrial dog-like gait.
just right for the evolution of small bipedal arboreal apes.
The fact that there are no small bipedal arboreal apes in Africa indicates that there was some climate shifting.
the southern Black Sea is between temperate and tropical.Correct. Southern Europe and the Black Sea are at the same latitudes.
This suggests they would tend to have the same climate. However, the
Black Sea is farther inland, and so suffers more continental extremes.
So any climate changes will appear first around the Black Sea and
become more extreme compared to southern Europe.
I'm talking about from 11ma through the MSC to 5ma. The Medit. & Red Seas dried out, the Black Sea didn't.
Moving toward 30 degrees latitude, rainfall becomes seasonally dry,
and then almost continuously dry. My understanding is, the only
native forests south of the Caspian are in the mountains, and adjacent
to the Mediterranean coasts. Arboreal apes of any kind would find
these deserts impassible.
You are speaking of recent climate. There are no arboreal apes there now.
cooking (fish .78ma) and earliest waternut gathering and bread making. The region is amenable to hominins & Homo.To a first approximation, average rainfall and temperature are
functions of latitude. However, while temperature is a function of
the sine of latitude, rainfall is more complex. It tends to be
continuously heavy near the equator, continuously dry near 30 degrees,
and seasonally variable between 30 and 60 degrees. This general
pattern is modified, sometimes dramatically, by terrain, ocean
currents, seasons, and Milankovitch cycles.
The most significant variable is Africa's northward tectonic
migration, about a centimeter a year since before the Miocene. So,
while central Africa has moved from south to north of the equator with
little effect, north Africa has approached and then went north of 30
degrees, making it over time ever drier, amplifying other climate
trends, making once wooded areas into vast savannah and desert.
Yes.
Also, Africa's tectonic slide north almost certainly pinched closed
the Gilbraltar Sttraits, which caused the Mediterranean to dry up at
least once, and likely several times as sea levels rose and fell. The
resulting hot salt basin would also have been impassible for arboreal
apes.
This is as true now as it was in theI would not claim nor disclaim that. The Levant is near the midpoint, extends the African Rift valley to Anatolia, is a major avian migration route between Africa and Eurasia, has fossil/artifacts of Homo erectus, neanderthal & sapiens oldest known
Miocene. This suggests to me there could not have been an unbroken
forested path for arboreal apes to migrate between Europe/Near East
and Central Africa.
I acknowledge the facts you describe above. However, the Levant is
savannah and desert except for a narrow strip along the Mediterranean
and up in the mountains. While this is no problem for terrestrial
bipeds like Homo, ISTM arboreal hominids like D.guggenmosi would have
a much harder time living/migrating there.
"is".
Again, refer to microclimate of Levant 11ma - 5ma. Today's Dead Sea was once the vast brackish Lake Lisan that reached to Lebanon, a gallery forest may have reached from Anatolia to Egypt.
What is ISTM?
This may have caused lordosis (the normal curvature of the human spine) and moved the center of mass over the hips and legs, which implies some habitual bipedal activity.Danuvius, Rudapithecus, Graecopithecus, Oranopithecus each had a unique trait shared with hominins. I think of them as a superspecies with local variations.-
If you place Danuvius half-way between fast brachiating bipedal long backed long achilles tendon hylobatids and bipedal Homo with long back and long achilles tendon, it fits perfectly.
Wiki:
Danuvius is thought to have had a broad chest. It is the first recorded Miocene great ape to have had the diaphragm located in the lower chest cavity, as in Homo, indicating an extended lower back and a greater number of functional lumbar vertebrae.
loading, and the ankle would have had a hinge-like function, being most stable if positioned perpendicularly to the leg as opposed to at an angle in apes. Danuvius was likely able to achieve a strong grip with its big toes, unlike modern African great
The robust finger and hypertrophied wrist and elbow bones indicate a strong grip and load bearing adaptations for the arms. The legs also show adaptations for load-bearing, especially at the hypertrophied knee joint. There was likely limited ankle
On Thu, 17 Nov 2022 15:53:51 -0800 (PST), Daud Deden
<daud....@gmail.com> wrote:
On Thursday, November 17, 2022 at 12:57:57 PM UTC-5, 69jp...@gmail.com wrote:
On Wed, 16 Nov 2022 22:42:03 -0800 (PST), Daud Deden
<daud....@gmail.com> wrote:
On Thursday, November 17, 2022 at 1:29:04 AM UTC-5, Daud Deden wrote:Not sure what you mean by "mature"; the individual or the species?
On Wednesday, November 16, 2022 at 11:08:11 AM UTC-5, 69jp...@gmail.com wrote:
On Fri, 04 Nov 2022 02:21:55 -0400, jillery <69jp...@gmail.com>
wrote:
On Thu, 3 Nov 2022 20:32:40 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Thursday, November 3, 2022 at 6:29:01 PM UTC-4, 69jp...@gmail.com wrote:
On Thu, 3 Nov 2022 07:56:05 -0700 (PDT), Daud DedenYes, I claim it is *descended from* European Miocene apes of the Black Sea region.
<daud....@gmail.com> wrote:
On Tuesday, November 1, 2022 at 4:17:31 AM UTC-4, 69jp...@gmail.com wrote:Sahelanthropus tchadensis is neither Miocene nor European, but is a
On Mon, 31 Oct 2022 15:15:01 -0700 (PDT), Daud DedenIn another video, she says that Sahelanthropus was the LCA of Homo / Pan, (though probably just in the general sense). https://www.youtube.com/watch?v=g4FTbZLkpzU&t=7s
<daud....@gmail.com> wrote:
On Monday, October 24, 2022 at 2:50:22 AM UTC-4, 69jp...@gmail.com wrote:Thank you for citing the above video. It's prelude to the ones I
Gutsick Gibbon is the Youtube handle of a biological anthropology PhD-
student named Eriks. Two of her recent videos discuss some of the
latest developments relating to the origins of human bipedalism:
<https://www.youtube.com/watch?v=kbQAgPSHbZE>
The above is a link to a 32-minute video where Erika discusses several
papers relating to Sahelanthropus tchadensis. This fossil is
remarkable in part because it's dated to about 7mya and was found in
central-african Chad, and also because it may be the oldest bipedal
hominin fossil found to date. However, there appears to be strong
disagreement whether the evidence supports bipedalism.
<https://www.youtube.com/watch?v=Nwkfkp360ps>
The above is a link to a 22-minute video where Erika discusses several
hypotheses about *why* our ancestors shifted to obligate bipedalism.
She discusses several hypotheses, and presents compelling arguments
for her preferred one.
Video by Erika on Lucy bipedalism: https://youtu.be/jo2ZLnucuHY
cited, and refers to them, and so complete a logical trilogy. >> >> > >>> >
In my view, Sahelanthropus is just a southwestern European Miocene ape *Descendant*, very similar to their eastern and northern kin. I see nothing palmigrade in any Miocene ape.
Pliocene central African species.
My impression is there isn't enough evidence to show whether Pliocene
African apes descended from Miocene European apes or Miocene African
apes. Either way, there was enough time between the two eras to have
evolved differences between either Miocene populations and Pliocene S.
tchadensis.
I have recently become aware of:
<https://en.wikipedia.org/wiki/Danuvius_guggenmosi>
which was a Miocene European ape that may have evolved arboreal
bipedalism similar to S.tchadensis.
Depending on how widespread its range, and how successful its
descendants, it's plausible they lived south of the Black Sea during >> >> > the late Miocene.
The question then becomes whether it's more likely these apes found >> >> > their way into Africa to become the ancestors of Pliocene
S.tchadensis, or whether S.tchadensis evolved from Miocene African >> >> > apes.
Unfortunately, the habitat of these apes made their fossil
preservation extremely rare, and so the evidence to well support
either hypothesis is lacking.
However, the question at least conditionally can be answered by
comparing the likelihood of a migratory pathway during that time,
versus the likelihood of arboreal bipedalism evolving independently in
two populations.
There are a number of anatomic features associated with arboreal
bipedalism, some of which are necessary, ex. anterior foramen magnum,
The foramen magnum is always situated relatively more anteriorly in immature than in mature apes.[ - and men. ]
Individually.My understanding is the relative position of foramen magnum doesn't
change significantly during human development.
Either way, the important point is the position and angle of foramen
magnum are diagnostic among all vertebrates for how they habitually
hold their head, and so includes/excludes bipedalism among hominids.
Yes, but no. Great apes are bipedal except when (hurrying) on open ground they adopt quadrupedalism. Homo retains the primitive bipedal gait of hominoid ancestors, as do hylobatids.All Homo species are great apes by definition, including H.sapiens.
They do/did quadrupedalism only in exceptional cases.
... and wet aka tropical,and some of which are incidental, ex. molar patterns. DescendantCentral Africa is and was hot,
populations are more likely to share these features than are
independent populations. This suggests to me that a sufficiently
robust fossil record could answer this question with some degree of >> >> > certainty.
Alternately, my understanding is southern Europe and central Africa >> >> > are ecological opposites, in the sense that when one is hot and dry >> >> > the other is temperate and wet.
The adoption of qpal knucklewalking by African apes indicates that their ancient habitat went through a dry phase (rainforest became patchy) forcing a terrestrial dog-like gait.Perhaps. My understanding is bipedal arboreal apes continued to walk bipedally on the ground, while non-bipedal arboreal apes also adopted quadrupedal habits on the ground.
just right for the evolution of small bipedal arboreal apes.
The fact that there are no small bipedal arboreal apes in Africa indicates that there was some climate shifting.Again perhaps. It also suggests small bipedal arboreal apes were outcompeted.
the southern Black Sea is between temperate and tropical.Correct. Southern Europe and the Black Sea are at the same latitudes.
This suggests they would tend to have the same climate. However, the
Black Sea is farther inland, and so suffers more continental extremes.
So any climate changes will appear first around the Black Sea and
become more extreme compared to southern Europe.
I'm talking about from 11ma through the MSC to 5ma. The Medit. & Red Seas dried out, the Black Sea didn't.The relative position of the Black Sea didn't change from then to now.
The important point is its position is deep in Eurasia, where
continental climates rule.
My understanding is the Mediterranean dried out only about 6mya, long
after European, and presumably Black Sea, arboreal apes went extinct.
The Red Sea is too far south to affect migration from Europe to Africa regardless of climate patterns.
Moving toward 30 degrees latitude, rainfall becomes seasonally dry,
and then almost continuously dry. My understanding is, the only
native forests south of the Caspian are in the mountains, and adjacent
to the Mediterranean coasts. Arboreal apes of any kind would find
these deserts impassible.
You are speaking of recent climate. There are no arboreal apes there now. No, I am speaking of climate then *and* now. Regions around 30degrees latitude tend to be drier than those around the equator, with exceptions due to terrain and ocean currents.
known cooking (fish .78ma) and earliest waternut gathering and bread making. The region is amenable to hominins & Homo.To a first approximation, average rainfall and temperature are
functions of latitude. However, while temperature is a function of
the sine of latitude, rainfall is more complex. It tends to be
continuously heavy near the equator, continuously dry near 30 degrees,
and seasonally variable between 30 and 60 degrees. This general
pattern is modified, sometimes dramatically, by terrain, ocean
currents, seasons, and Milankovitch cycles.
The most significant variable is Africa's northward tectonic
migration, about a centimeter a year since before the Miocene. So,
while central Africa has moved from south to north of the equator with
little effect, north Africa has approached and then went north of 30
degrees, making it over time ever drier, amplifying other climate
trends, making once wooded areas into vast savannah and desert.
Yes.
Also, Africa's tectonic slide north almost certainly pinched closed
the Gilbraltar Sttraits, which caused the Mediterranean to dry up at
least once, and likely several times as sea levels rose and fell. The
resulting hot salt basin would also have been impassible for arboreal
apes.
This is as true now as it was in theI would not claim nor disclaim that. The Levant is near the midpoint, extends the African Rift valley to Anatolia, is a major avian migration route between Africa and Eurasia, has fossil/artifacts of Homo erectus, neanderthal & sapiens oldest
Miocene. This suggests to me there could not have been an unbroken >> >> > forested path for arboreal apes to migrate between Europe/Near East >> >> > and Central Africa.
I acknowledge the facts you describe above. However, the Levant is
savannah and desert except for a narrow strip along the Mediterranean
and up in the mountains. While this is no problem for terrestrial
bipeds like Homo, ISTM arboreal hominids like D.guggenmosi would have
a much harder time living/migrating there.
"is".The regions you describe above are part of the Mediterranean coastal mountains I mentioned previously.
Again, refer to microclimate of Levant 11ma - 5ma. Today's Dead Sea was once the vast brackish Lake Lisan that reached to Lebanon, a gallery forest may have reached from Anatolia to Egypt.
forest is plausible.
insufficient to say if it would have been as extensive and continuous
as you suggest during the time you suggest.
What is ISTM?
It's shorthand acronym for "It Seems To Me"
This may have caused lordosis (the normal curvature of the human spine) and moved the center of mass over the hips and legs, which implies some habitual bipedal activity.Danuvius, Rudapithecus, Graecopithecus, Oranopithecus each had a unique trait shared with hominins. I think of them as a superspecies with local variations.-
If you place Danuvius half-way between fast brachiating bipedal long backed long achilles tendon hylobatids and bipedal Homo with long back and long achilles tendon, it fits perfectly.
Wiki:
Danuvius is thought to have had a broad chest. It is the first recorded Miocene great ape to have had the diaphragm located in the lower chest cavity, as in Homo, indicating an extended lower back and a greater number of functional lumbar vertebrae.
loading, and the ankle would have had a hinge-like function, being most stable if positioned perpendicularly to the leg as opposed to at an angle in apes. Danuvius was likely able to achieve a strong grip with its big toes, unlike modern African great
The robust finger and hypertrophied wrist and elbow bones indicate a strong grip and load bearing adaptations for the arms. The legs also show adaptations for load-bearing, especially at the hypertrophied knee joint. There was likely limited ankle
On Friday, November 18, 2022 at 2:12:32 AM UTC-5, 69jp...@gmail.com wrote:known cooking (fish .78ma) and earliest waternut gathering and bread making. The region is amenable to hominins & Homo.
On Thu, 17 Nov 2022 15:53:51 -0800 (PST), Daud Deden
<daud....@gmail.com> wrote:
On Thursday, November 17, 2022 at 12:57:57 PM UTC-5, 69jp...@gmail.com wrote:
On Wed, 16 Nov 2022 22:42:03 -0800 (PST), Daud Deden
<daud....@gmail.com> wrote:
On Thursday, November 17, 2022 at 1:29:04 AM UTC-5, Daud Deden wrote: >> >> On Wednesday, November 16, 2022 at 11:08:11 AM UTC-5, 69jp...@gmail.com wrote:Not sure what you mean by "mature"; the individual or the species?
On Fri, 04 Nov 2022 02:21:55 -0400, jillery <69jp...@gmail.com>
wrote:
On Thu, 3 Nov 2022 20:32:40 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Thursday, November 3, 2022 at 6:29:01 PM UTC-4, 69jp...@gmail.com wrote:
On Thu, 3 Nov 2022 07:56:05 -0700 (PDT), Daud DedenYes, I claim it is *descended from* European Miocene apes of the Black Sea region.
<daud....@gmail.com> wrote:
On Tuesday, November 1, 2022 at 4:17:31 AM UTC-4, 69jp...@gmail.com wrote:Sahelanthropus tchadensis is neither Miocene nor European, but is a
On Mon, 31 Oct 2022 15:15:01 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Monday, October 24, 2022 at 2:50:22 AM UTC-4, 69jp...@gmail.com wrote:Thank you for citing the above video. It's prelude to the ones I
Gutsick Gibbon is the Youtube handle of a biological anthropology PhD-
student named Eriks. Two of her recent videos discuss some of the
latest developments relating to the origins of human bipedalism:
<https://www.youtube.com/watch?v=kbQAgPSHbZE>
The above is a link to a 32-minute video where Erika discusses several
papers relating to Sahelanthropus tchadensis. This fossil is
remarkable in part because it's dated to about 7mya and was found in
central-african Chad, and also because it may be the oldest bipedal
hominin fossil found to date. However, there appears to be strong
disagreement whether the evidence supports bipedalism. >> >> > >>> >> >>
<https://www.youtube.com/watch?v=Nwkfkp360ps>
The above is a link to a 22-minute video where Erika discusses several
hypotheses about *why* our ancestors shifted to obligate bipedalism.
She discusses several hypotheses, and presents compelling arguments
for her preferred one.
Video by Erika on Lucy bipedalism: https://youtu.be/jo2ZLnucuHY
cited, and refers to them, and so complete a logical trilogy.
In another video, she says that Sahelanthropus was the LCA of Homo / Pan, (though probably just in the general sense). https://www.youtube.com/watch?v=g4FTbZLkpzU&t=7s
In my view, Sahelanthropus is just a southwestern European Miocene ape *Descendant*, very similar to their eastern and northern kin. I see nothing palmigrade in any Miocene ape.
Pliocene central African species.
My impression is there isn't enough evidence to show whether Pliocene
African apes descended from Miocene European apes or Miocene African
apes. Either way, there was enough time between the two eras to have
evolved differences between either Miocene populations and Pliocene S.
tchadensis.
I have recently become aware of:
<https://en.wikipedia.org/wiki/Danuvius_guggenmosi>
which was a Miocene European ape that may have evolved arboreal
bipedalism similar to S.tchadensis.
Depending on how widespread its range, and how successful its
descendants, it's plausible they lived south of the Black Sea during
the late Miocene.
The question then becomes whether it's more likely these apes found
their way into Africa to become the ancestors of Pliocene
S.tchadensis, or whether S.tchadensis evolved from Miocene African >> >> > apes.
Unfortunately, the habitat of these apes made their fossil
preservation extremely rare, and so the evidence to well support >> >> > either hypothesis is lacking.
However, the question at least conditionally can be answered by
comparing the likelihood of a migratory pathway during that time, >> >> > versus the likelihood of arboreal bipedalism evolving independently in
two populations.
There are a number of anatomic features associated with arboreal >> >> > bipedalism, some of which are necessary, ex. anterior foramen magnum,
The foramen magnum is always situated relatively more anteriorly in immature than in mature apes.[ - and men. ]
Right. In chimps the muzzle gradually moves anteriorly relative to the foramen magnum, in Homo only the nose does.Individually.My understanding is the relative position of foramen magnum doesn't
change significantly during human development.
Sorry, I erred above, I'd meant "...than in mature apes." The "and men" was NOT meant, I thought I'd erased it! Oops.
Either way, the important point is the position and angle of foramen
magnum are diagnostic among all vertebrates for how they habitually
hold their head, and so includes/excludes bipedalism among hominids.
Yes, I meant 'arboreal great apes'. Humans are terrestrial great apes, hylobatids are arboreal lesser apes.Yes, but no. Great apes are bipedal except when (hurrying) on open ground they adopt quadrupedalism. Homo retains the primitive bipedal gait of hominoid ancestors, as do hylobatids.All Homo species are great apes by definition, including H.sapiens.
They do/did quadrupedalism only in exceptional cases.https://youtu.be/pCrH6BOwxe4 15mph qpal running as a patas monkey, not a chimp.
... and wet aka tropical,and some of which are incidental, ex. molar patterns. Descendant >> >> > populations are more likely to share these features than areCentral Africa is and was hot,
independent populations. This suggests to me that a sufficiently >> >> > robust fossil record could answer this question with some degree of
certainty.
Alternately, my understanding is southern Europe and central Africa
are ecological opposites, in the sense that when one is hot and dry
the other is temperate and wet.
Bipedal walking is primitive in arboreal hominoids, quadrupedal walking is derived. I don't know of any 'non-bipedal arboreal apes', only monkeys.The adoption of qpal knucklewalking by African apes indicates that their ancient habitat went through a dry phase (rainforest became patchy) forcing a terrestrial dog-like gait.Perhaps. My understanding is bipedal arboreal apes continued to walk bipedally on the ground, while non-bipedal arboreal apes also adopted quadrupedal habits on the ground.
just right for the evolution of small bipedal arboreal apes.
They were, by monkeys which were more ground adapted, able to swiftly run between forest stands during a drier climate phase.The fact that there are no small bipedal arboreal apes in Africa indicates that there was some climate shifting.Again perhaps. It also suggests small bipedal arboreal apes were outcompeted.
the southern Black Sea is between temperate and tropical.Correct. Southern Europe and the Black Sea are at the same latitudes. >> This suggests they would tend to have the same climate. However, the
Black Sea is farther inland, and so suffers more continental extremes. >> So any climate changes will appear first around the Black Sea and
become more extreme compared to southern Europe.
It lies between the Atlantic-Mediterranean and the Caspian Sea, in the Peri-Tethyan basin, protected by the high Iranian plateau to the south. Not a typical continental climate.I'm talking about from 11ma through the MSC to 5ma. The Medit. & Red Seas dried out, the Black Sea didn't.The relative position of the Black Sea didn't change from then to now.
The important point is its position is deep in Eurasia, where
continental climates rule.
My understanding is the Mediterranean dried out only about 6mya, long after European, and presumably Black Sea, arboreal apes went extinct.No, Danuvius and later Miocene apes there were of one lineage IMO, that may have lived there until 5ma, with successive expansional waves emigrating outwardly including towards Africa.
The Red Sea is too far south to affect migration from Europe to Africa regardless of climate patterns.It is part of the African-Anatolian rift.
Moving toward 30 degrees latitude, rainfall becomes seasonally dry,
and then almost continuously dry. My understanding is, the only
native forests south of the Caspian are in the mountains, and adjacent >> to the Mediterranean coasts. Arboreal apes of any kind would find
these deserts impassible.
You appear to be claiming that the European Miocene apes could never have been linked to African and Asian apes. Yet they certainly were, else they wouldn't have existed at all.You are speaking of recent climate. There are no arboreal apes there now. No, I am speaking of climate then *and* now. Regions around 30degrees latitude tend to be drier than those around the equator, with exceptions due to terrain and ocean currents.
To a first approximation, average rainfall and temperature are
functions of latitude. However, while temperature is a function of
the sine of latitude, rainfall is more complex. It tends to be
continuously heavy near the equator, continuously dry near 30 degrees, >> and seasonally variable between 30 and 60 degrees. This general
pattern is modified, sometimes dramatically, by terrain, ocean
currents, seasons, and Milankovitch cycles.
The most significant variable is Africa's northward tectonic
migration, about a centimeter a year since before the Miocene. So,
while central Africa has moved from south to north of the equator with >> little effect, north Africa has approached and then went north of 30
degrees, making it over time ever drier, amplifying other climate
trends, making once wooded areas into vast savannah and desert.
Yes.
Also, Africa's tectonic slide north almost certainly pinched closed
the Gilbraltar Sttraits, which caused the Mediterranean to dry up at
least once, and likely several times as sea levels rose and fell. The >> resulting hot salt basin would also have been impassible for arboreal >> apes.
This is as true now as it was in theI would not claim nor disclaim that. The Levant is near the midpoint, extends the African Rift valley to Anatolia, is a major avian migration route between Africa and Eurasia, has fossil/artifacts of Homo erectus, neanderthal & sapiens oldest
Miocene. This suggests to me there could not have been an unbroken >> >> > forested path for arboreal apes to migrate between Europe/Near East
and Central Africa.
I acknowledge the facts you describe above. However, the Levant is
savannah and desert except for a narrow strip along the Mediterranean >> and up in the mountains. While this is no problem for terrestrial
bipeds like Homo, ISTM arboreal hominids like D.guggenmosi would have >> a much harder time living/migrating there.
The Dead Sea is by no means a coastal mountain region."is".The regions you describe above are part of the Mediterranean coastal mountains I mentioned previously.
Again, refer to microclimate of Levant 11ma - 5ma. Today's Dead Sea was once the vast brackish Lake Lisan that reached to Lebanon, a gallery forest may have reached from Anatolia to Egypt.
I agree a coastal Mediterranean
forest is plausible.I'm referring to the tectonic rift valley between Zimbabwe/Zambia and Lebanon/Anatolia.
Of course, there were coastal forests as well, but they were affected by the MSC.
However, my understanding is the evidence is
insufficient to say if it would have been as extensive and continuousHaven't got enough hard data yet.
as you suggest during the time you suggest.
What is ISTM?
vertebrae. This may have caused lordosis (the normal curvature of the human spine) and moved the center of mass over the hips and legs, which implies some habitual bipedal activity.It's shorthand acronym for "It Seems To Me"Ok, thanks.
Danuvius, Rudapithecus, Graecopithecus, Oranopithecus each had a unique trait shared with hominins. I think of them as a superspecies with local variations.-
If you place Danuvius half-way between fast brachiating bipedal long backed long achilles tendon hylobatids and bipedal Homo with long back and long achilles tendon, it fits perfectly.
Wiki:
Danuvius is thought to have had a broad chest. It is the first recorded Miocene great ape to have had the diaphragm located in the lower chest cavity, as in Homo, indicating an extended lower back and a greater number of functional lumbar
ankle loading, and the ankle would have had a hinge-like function, being most stable if positioned perpendicularly to the leg as opposed to at an angle in apes. Danuvius was likely able to achieve a strong grip with its big toes, unlike modern African
The robust finger and hypertrophied wrist and elbow bones indicate a strong grip and load bearing adaptations for the arms. The legs also show adaptations for load-bearing, especially at the hypertrophied knee joint. There was likely limited
On Friday, November 18, 2022 at 2:12:32 AM UTC-5, 69jp...@gmail.com wrote:
On Thu, 17 Nov 2022 15:53:51 -0800 (PST), Daud Deden
<daud....@gmail.com> wrote:
On Thursday, November 17, 2022 at 12:57:57 PM UTC-5, 69jp...@gmail.com wrote:My understanding is the relative position of foramen magnum doesn't
On Wed, 16 Nov 2022 22:42:03 -0800 (PST), Daud Deden
<daud....@gmail.com> wrote:
On Thursday, November 17, 2022 at 1:29:04 AM UTC-5, Daud Deden wrote: >> >> >> On Wednesday, November 16, 2022 at 11:08:11 AM UTC-5, 69jp...@gmail.com wrote:Not sure what you mean by "mature"; the individual or the species?
On Fri, 04 Nov 2022 02:21:55 -0400, jillery <69jp...@gmail.com>
wrote:
On Thu, 3 Nov 2022 20:32:40 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Thursday, November 3, 2022 at 6:29:01 PM UTC-4, 69jp...@gmail.com wrote:
On Thu, 3 Nov 2022 07:56:05 -0700 (PDT), Daud DedenYes, I claim it is *descended from* European Miocene apes of the Black Sea region.
<daud....@gmail.com> wrote:
On Tuesday, November 1, 2022 at 4:17:31 AM UTC-4, 69jp...@gmail.com wrote:Sahelanthropus tchadensis is neither Miocene nor European, but is a
On Mon, 31 Oct 2022 15:15:01 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Monday, October 24, 2022 at 2:50:22 AM UTC-4, 69jp...@gmail.com wrote:Thank you for citing the above video. It's prelude to the ones I
Gutsick Gibbon is the Youtube handle of a biological anthropology PhD-
student named Eriks. Two of her recent videos discuss some of the
latest developments relating to the origins of human bipedalism:
<https://www.youtube.com/watch?v=kbQAgPSHbZE>
The above is a link to a 32-minute video where Erika discusses several
papers relating to Sahelanthropus tchadensis. This fossil is
remarkable in part because it's dated to about 7mya and was found in
central-african Chad, and also because it may be the oldest bipedal
hominin fossil found to date. However, there appears to be strong
disagreement whether the evidence supports bipedalism.
<https://www.youtube.com/watch?v=Nwkfkp360ps>
The above is a link to a 22-minute video where Erika discusses several
hypotheses about *why* our ancestors shifted to obligate bipedalism.
She discusses several hypotheses, and presents compelling arguments
for her preferred one.
Video by Erika on Lucy bipedalism: https://youtu.be/jo2ZLnucuHY
cited, and refers to them, and so complete a logical trilogy.
In another video, she says that Sahelanthropus was the LCA of Homo / Pan, (though probably just in the general sense). https://www.youtube.com/watch?v=g4FTbZLkpzU&t=7s
In my view, Sahelanthropus is just a southwestern European Miocene ape *Descendant*, very similar to their eastern and northern kin. I see nothing palmigrade in any Miocene ape.
Pliocene central African species.
My impression is there isn't enough evidence to show whether Pliocene
African apes descended from Miocene European apes or Miocene African
apes. Either way, there was enough time between the two eras to have
evolved differences between either Miocene populations and Pliocene S.
tchadensis.
I have recently become aware of:
<https://en.wikipedia.org/wiki/Danuvius_guggenmosi>
which was a Miocene European ape that may have evolved arboreal
bipedalism similar to S.tchadensis.
Depending on how widespread its range, and how successful its
descendants, it's plausible they lived south of the Black Sea during
the late Miocene.
The question then becomes whether it's more likely these apes found >> >> >> > their way into Africa to become the ancestors of Pliocene
S.tchadensis, or whether S.tchadensis evolved from Miocene African >> >> >> > apes.
Unfortunately, the habitat of these apes made their fossil
preservation extremely rare, and so the evidence to well support
either hypothesis is lacking.
However, the question at least conditionally can be answered by
comparing the likelihood of a migratory pathway during that time, >> >> >> > versus the likelihood of arboreal bipedalism evolving independently in
two populations.
There are a number of anatomic features associated with arboreal
bipedalism, some of which are necessary, ex. anterior foramen magnum,
The foramen magnum is always situated relatively more anteriorly in immature than in mature apes.[ - and men. ]
Individually.
change significantly during human development.
Right. In chimps the muzzle gradually moves anteriorly relative to the foramen magnum, in Homo only the nose does.
Sorry, I erred above, I'd meant "...than in mature apes." The "and men" was NOT meant, I thought I'd erased it! Oops.
All Homo species are great apes by definition, including H.sapiens.Either way, the important point is the position and angle of foramen
magnum are diagnostic among all vertebrates for how they habitually
hold their head, and so includes/excludes bipedalism among hominids.
Yes, but no. Great apes are bipedal except when (hurrying) on open ground they adopt quadrupedalism. Homo retains the primitive bipedal gait of hominoid ancestors, as do hylobatids.
Yes, I meant 'arboreal great apes'. Humans are terrestrial great apes, hylobatids are arboreal lesser apes.
They do/did quadrupedalism only in exceptional cases.
https://youtu.be/pCrH6BOwxe4 15mph qpal running as a patas monkey, not a chimp.
Perhaps. My understanding is bipedal arboreal apes continued to walk... and wet aka tropical,and some of which are incidental, ex. molar patterns. DescendantCentral Africa is and was hot,
populations are more likely to share these features than are
independent populations. This suggests to me that a sufficiently
robust fossil record could answer this question with some degree of >> >> >> > certainty.
Alternately, my understanding is southern Europe and central Africa >> >> >> > are ecological opposites, in the sense that when one is hot and dry >> >> >> > the other is temperate and wet.
The adoption of qpal knucklewalking by African apes indicates that their ancient habitat went through a dry phase (rainforest became patchy) forcing a terrestrial dog-like gait.
bipedally on the ground, while non-bipedal arboreal apes also adopted
quadrupedal habits on the ground.
Bipedal walking is primitive in arboreal hominoids, quadrupedal walking is derived. I don't know of any 'non-bipedal arboreal apes', only monkeys.
Again perhaps. It also suggests small bipedal arboreal apes werejust right for the evolution of small bipedal arboreal apes.
The fact that there are no small bipedal arboreal apes in Africa indicates that there was some climate shifting.
outcompeted.
They were, by monkeys which were more ground adapted, able to swiftly run between forest stands during a drier climate phase.
The relative position of the Black Sea didn't change from then to now.the southern Black Sea is between temperate and tropical.Correct. Southern Europe and the Black Sea are at the same latitudes.
This suggests they would tend to have the same climate. However, the
Black Sea is farther inland, and so suffers more continental extremes. >> >> So any climate changes will appear first around the Black Sea and
become more extreme compared to southern Europe.
I'm talking about from 11ma through the MSC to 5ma. The Medit. & Red Seas dried out, the Black Sea didn't.
The important point is its position is deep in Eurasia, where
continental climates rule.
It lies between the Atlantic-Mediterranean and the Caspian Sea, in the Peri-Tethyan basin, protected by the high Iranian plateau to the south. Not a typical continental climate.
My understanding is the Mediterranean dried out only about 6mya, long
after European, and presumably Black Sea, arboreal apes went extinct.
No, Danuvius and later Miocene apes there were of one lineage IMO, that may have lived there until 5ma, with successive expansional waves emigrating outwardly including towards Africa.
The Red Sea is too far south to affect migration from Europe to Africa
regardless of climate patterns.
It is part of the African-Anatolian rift.
degrees latitude tend to be drier than those around the equator, withMoving toward 30 degrees latitude, rainfall becomes seasonally dry,
and then almost continuously dry. My understanding is, the only
native forests south of the Caspian are in the mountains, and adjacent >> >> to the Mediterranean coasts. Arboreal apes of any kind would find
these deserts impassible.
You are speaking of recent climate. There are no arboreal apes there now. >> No, I am speaking of climate then *and* now. Regions around 30
exceptions due to terrain and ocean currents.
You appear to be claiming that the European Miocene apes could never have been linked to African and Asian apes. Yet they certainly were, else they wouldn't have existed at all.
known cooking (fish .78ma) and earliest waternut gathering and bread making. The region is amenable to hominins & Homo.To a first approximation, average rainfall and temperature are
functions of latitude. However, while temperature is a function of
the sine of latitude, rainfall is more complex. It tends to be
continuously heavy near the equator, continuously dry near 30 degrees, >> >> and seasonally variable between 30 and 60 degrees. This general
pattern is modified, sometimes dramatically, by terrain, ocean
currents, seasons, and Milankovitch cycles.
The most significant variable is Africa's northward tectonic
migration, about a centimeter a year since before the Miocene. So,
while central Africa has moved from south to north of the equator with >> >> little effect, north Africa has approached and then went north of 30
degrees, making it over time ever drier, amplifying other climate
trends, making once wooded areas into vast savannah and desert.
Yes.
Also, Africa's tectonic slide north almost certainly pinched closed
the Gilbraltar Sttraits, which caused the Mediterranean to dry up at
least once, and likely several times as sea levels rose and fell. The
resulting hot salt basin would also have been impassible for arboreal
apes.
This is as true now as it was in theI would not claim nor disclaim that. The Levant is near the midpoint, extends the African Rift valley to Anatolia, is a major avian migration route between Africa and Eurasia, has fossil/artifacts of Homo erectus, neanderthal & sapiens oldest
Miocene. This suggests to me there could not have been an unbroken >> >> >> > forested path for arboreal apes to migrate between Europe/Near East >> >> >> > and Central Africa.
The regions you describe above are part of the Mediterranean coastalI acknowledge the facts you describe above. However, the Levant is
savannah and desert except for a narrow strip along the Mediterranean
and up in the mountains. While this is no problem for terrestrial
bipeds like Homo, ISTM arboreal hominids like D.guggenmosi would have
a much harder time living/migrating there.
"is".
Again, refer to microclimate of Levant 11ma - 5ma. Today's Dead Sea was once the vast brackish Lake Lisan that reached to Lebanon, a gallery forest may have reached from Anatolia to Egypt.
mountains I mentioned previously.
The Dead Sea is by no means a coastal mountain region.
I agree a coastal Mediterranean
forest is plausible.
I'm referring to the tectonic rift valley between Zimbabwe/Zambia and Lebanon/Anatolia.
Of course, there were coastal forests as well, but they were affected by the MSC.
However, my understanding is the evidence is
insufficient to say if it would have been as extensive and continuous
as you suggest during the time you suggest.
Haven't got enough hard data yet.
vertebrae. This may have caused lordosis (the normal curvature of the human spine) and moved the center of mass over the hips and legs, which implies some habitual bipedal activity.What is ISTM?
It's shorthand acronym for "It Seems To Me"
Ok, thanks.
Danuvius, Rudapithecus, Graecopithecus, Oranopithecus each had a unique trait shared with hominins. I think of them as a superspecies with local variations.-
If you place Danuvius half-way between fast brachiating bipedal long backed long achilles tendon hylobatids and bipedal Homo with long back and long achilles tendon, it fits perfectly.
Wiki:
Danuvius is thought to have had a broad chest. It is the first recorded Miocene great ape to have had the diaphragm located in the lower chest cavity, as in Homo, indicating an extended lower back and a greater number of functional lumbar
loading, and the ankle would have had a hinge-like function, being most stable if positioned perpendicularly to the leg as opposed to at an angle in apes. Danuvius was likely able to achieve a strong grip with its big toes, unlike modern African great
The robust finger and hypertrophied wrist and elbow bones indicate a strong grip and load bearing adaptations for the arms. The legs also show adaptations for load-bearing, especially at the hypertrophied knee joint. There was likely limited ankle
On Fri, 18 Nov 2022 03:45:32 -0800 (PST), Daud Deden
<daud....@gmail.com> wrote:
On Friday, November 18, 2022 at 2:12:32 AM UTC-5, 69jp...@gmail.com wrote: >> On Thu, 17 Nov 2022 15:53:51 -0800 (PST), Daud Deden
<daud....@gmail.com> wrote:
On Thursday, November 17, 2022 at 12:57:57 PM UTC-5, 69jp...@gmail.com wrote:My understanding is the relative position of foramen magnum doesn't
On Wed, 16 Nov 2022 22:42:03 -0800 (PST), Daud Deden
<daud....@gmail.com> wrote:
On Thursday, November 17, 2022 at 1:29:04 AM UTC-5, Daud Deden wrote: >> >> >> On Wednesday, November 16, 2022 at 11:08:11 AM UTC-5, 69jp...@gmail.com wrote:Not sure what you mean by "mature"; the individual or the species?
On Fri, 04 Nov 2022 02:21:55 -0400, jillery <69jp...@gmail.com> >> >> >> > wrote:
On Thu, 3 Nov 2022 20:32:40 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Thursday, November 3, 2022 at 6:29:01 PM UTC-4, 69jp...@gmail.com wrote:
On Thu, 3 Nov 2022 07:56:05 -0700 (PDT), Daud DedenYes, I claim it is *descended from* European Miocene apes of the Black Sea region.
<daud....@gmail.com> wrote:
On Tuesday, November 1, 2022 at 4:17:31 AM UTC-4, 69jp...@gmail.com wrote:Sahelanthropus tchadensis is neither Miocene nor European, but is a
On Mon, 31 Oct 2022 15:15:01 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Monday, October 24, 2022 at 2:50:22 AM UTC-4, 69jp...@gmail.com wrote:Thank you for citing the above video. It's prelude to the ones I
Gutsick Gibbon is the Youtube handle of a biological anthropology PhD-
student named Eriks. Two of her recent videos discuss some of the
latest developments relating to the origins of human bipedalism:
<https://www.youtube.com/watch?v=kbQAgPSHbZE>
The above is a link to a 32-minute video where Erika discusses several
papers relating to Sahelanthropus tchadensis. This fossil is
remarkable in part because it's dated to about 7mya and was found in
central-african Chad, and also because it may be the oldest bipedal
hominin fossil found to date. However, there appears to be strong
disagreement whether the evidence supports bipedalism. >> >> >> > >>> >> >>
<https://www.youtube.com/watch?v=Nwkfkp360ps>
The above is a link to a 22-minute video where Erika discusses several
hypotheses about *why* our ancestors shifted to obligate bipedalism.
She discusses several hypotheses, and presents compelling arguments
for her preferred one.
Video by Erika on Lucy bipedalism: https://youtu.be/jo2ZLnucuHY
cited, and refers to them, and so complete a logical trilogy.
In another video, she says that Sahelanthropus was the LCA of Homo / Pan, (though probably just in the general sense). https://www.youtube.com/watch?v=g4FTbZLkpzU&t=7s
In my view, Sahelanthropus is just a southwestern European Miocene ape *Descendant*, very similar to their eastern and northern kin. I see nothing palmigrade in any Miocene ape.
Pliocene central African species.
My impression is there isn't enough evidence to show whether Pliocene
African apes descended from Miocene European apes or Miocene African
apes. Either way, there was enough time between the two eras to have
evolved differences between either Miocene populations and Pliocene S.
tchadensis.
I have recently become aware of:
<https://en.wikipedia.org/wiki/Danuvius_guggenmosi>
which was a Miocene European ape that may have evolved arboreal >> >> >> > bipedalism similar to S.tchadensis.
Depending on how widespread its range, and how successful its
descendants, it's plausible they lived south of the Black Sea during
the late Miocene.
The question then becomes whether it's more likely these apes found
their way into Africa to become the ancestors of Pliocene
S.tchadensis, or whether S.tchadensis evolved from Miocene African
apes.
Unfortunately, the habitat of these apes made their fossil
preservation extremely rare, and so the evidence to well support >> >> >> > either hypothesis is lacking.
However, the question at least conditionally can be answered by >> >> >> > comparing the likelihood of a migratory pathway during that time, >> >> >> > versus the likelihood of arboreal bipedalism evolving independently in
two populations.
There are a number of anatomic features associated with arboreal >> >> >> > bipedalism, some of which are necessary, ex. anterior foramen magnum,
The foramen magnum is always situated relatively more anteriorly in immature than in mature apes.[ - and men. ]
Individually.
change significantly during human development.
Right. In chimps the muzzle gradually moves anteriorly relative to the foramen magnum, in Homo only the nose does.The positions of the muzzle and/or nose relative to the foramen magnum
Sorry, I erred above, I'd meant "...than in mature apes." The "and men" was NOT meant, I thought I'd erased it! Oops.
don't inform bipedalism.
How is that an exceptional case among hominins? Only Usain Bolt can outrun qpal chimp at top speed.All Homo species are great apes by definition, including H.sapiens.Either way, the important point is the position and angle of foramen >> >> magnum are diagnostic among all vertebrates for how they habituallyYes, but no. Great apes are bipedal except when (hurrying) on open ground they adopt quadrupedalism. Homo retains the primitive bipedal gait of hominoid ancestors, as do hylobatids.
hold their head, and so includes/excludes bipedalism among hominids. >> >
Yes, I meant 'arboreal great apes'. Humans are terrestrial great apes, hylobatids are arboreal lesser apes.
They do/did quadrupedalism only in exceptional cases.
https://youtu.be/pCrH6BOwxe4 15mph qpal running as a patas monkey, not a chimp.Imagine how much faster that person would be if he ran normally, like
this:
<https://www.youtube.com/watch?v=k3PZgbQ8auE>
Perhaps. My understanding is bipedal arboreal apes continued to walk... and wet aka tropical,and some of which are incidental, ex. molar patterns. Descendant >> >> >> > populations are more likely to share these features than areCentral Africa is and was hot,
independent populations. This suggests to me that a sufficiently >> >> >> > robust fossil record could answer this question with some degree of
certainty.
Alternately, my understanding is southern Europe and central Africa
are ecological opposites, in the sense that when one is hot and dry
the other is temperate and wet.
The adoption of qpal knucklewalking by African apes indicates that their ancient habitat went through a dry phase (rainforest became patchy) forcing a terrestrial dog-like gait.
bipedally on the ground, while non-bipedal arboreal apes also adopted
quadrupedal habits on the ground.
Bipedal walking is primitive in arboreal hominoids, quadrupedal walking is derived. I don't know of any 'non-bipedal arboreal apes', only monkeys.That's not my understanding. My understanding is chimpanzees,
gorillas, and orangutans are non-bipedal arboreal apes, meaning when
they are in the trees, they do not walk upright.
arboreal apes prior to Australopithecines.
Again perhaps. It also suggests small bipedal arboreal apes werejust right for the evolution of small bipedal arboreal apes.
The fact that there are no small bipedal arboreal apes in Africa indicates that there was some climate shifting.
outcompeted.
They were, by monkeys which were more ground adapted, able to swiftly run between forest stands during a drier climate phase.
The relative position of the Black Sea didn't change from then to now.the southern Black Sea is between temperate and tropical.Correct. Southern Europe and the Black Sea are at the same latitudes. >> >> This suggests they would tend to have the same climate. However, the >> >> Black Sea is farther inland, and so suffers more continental extremes. >> >> So any climate changes will appear first around the Black Sea and
become more extreme compared to southern Europe.
I'm talking about from 11ma through the MSC to 5ma. The Medit. & Red Seas dried out, the Black Sea didn't.
The important point is its position is deep in Eurasia, where
continental climates rule.
It lies between the Atlantic-Mediterranean and the Caspian Sea, in the Peri-Tethyan basin, protected by the high Iranian plateau to the south. Not a typical continental climate.<https://www.britannica.com/place/Black-Sea/Climate> **********************************
The climate of the landlocked Black Sea can be characterized generally
as continental (i.e., subject to pronounced seasonal temperature variations), although climatic conditions in some parts of the basin
are controlled to a great extent by the shoreline relief. A steppe
climate, with cold winters and hot, dry summers, is found in the northwestern part of the basin exposed to the influence of air masses
from the north.
************************************
My understanding is the Mediterranean dried out only about 6mya, long
after European, and presumably Black Sea, arboreal apes went extinct.
No, Danuvius and later Miocene apes there were of one lineage IMO, that may have lived there until 5ma, with successive expansional waves emigrating outwardly including towards Africa.
The Red Sea is too far south to affect migration from Europe to Africa
regardless of climate patterns.
It is part of the African-Anatolian rift.I acknowledge that rift was one plausible pathway from Europe to
Africa. The Red Sea was not, nor did it block such a pathway.
No, I am speaking of climate then *and* now. Regions around 30Moving toward 30 degrees latitude, rainfall becomes seasonally dry,
and then almost continuously dry. My understanding is, the only
native forests south of the Caspian are in the mountains, and adjacent >> >> to the Mediterranean coasts. Arboreal apes of any kind would find
these deserts impassible.
You are speaking of recent climate. There are no arboreal apes there now.
degrees latitude tend to be drier than those around the equator, with
exceptions due to terrain and ocean currents.
known cooking (fish .78ma) and earliest waternut gathering and bread making. The region is amenable to hominins & Homo.You appear to be claiming that the European Miocene apes could never have been linked to African and Asian apes. Yet they certainly were, else they wouldn't have existed at all.Such an "appearance" is incorrect. In certain cases, regions around
30 degrees latitude have/had enough rainfall to support forests. The relevant point here is, global climate since the Miocene has gotten
colder and drier, especially around 30 degrees latitude, which has led
to the creation of large areas of treeless savannah and desert. I
don't know when European and African forests separated. Do you?
Also, the question isn't about the origin of apes generally. It's
about the origin of arboreal bipedal apes. We know they existed in
Pliocene Africa. They *may* have existed in Miocene Europe. Even if
they did, the two populations may still have evolved independently.
To a first approximation, average rainfall and temperature are
functions of latitude. However, while temperature is a function of
the sine of latitude, rainfall is more complex. It tends to be
continuously heavy near the equator, continuously dry near 30 degrees, >> >> and seasonally variable between 30 and 60 degrees. This general
pattern is modified, sometimes dramatically, by terrain, ocean
currents, seasons, and Milankovitch cycles.
The most significant variable is Africa's northward tectonic
migration, about a centimeter a year since before the Miocene. So,
while central Africa has moved from south to north of the equator with >> >> little effect, north Africa has approached and then went north of 30 >> >> degrees, making it over time ever drier, amplifying other climate
trends, making once wooded areas into vast savannah and desert.
Yes.
Also, Africa's tectonic slide north almost certainly pinched closed
the Gilbraltar Sttraits, which caused the Mediterranean to dry up at >> >> least once, and likely several times as sea levels rose and fell. The >> >> resulting hot salt basin would also have been impassible for arboreal >> >> apes.
This is as true now as it was in theI would not claim nor disclaim that. The Levant is near the midpoint, extends the African Rift valley to Anatolia, is a major avian migration route between Africa and Eurasia, has fossil/artifacts of Homo erectus, neanderthal & sapiens oldest
Miocene. This suggests to me there could not have been an unbroken
forested path for arboreal apes to migrate between Europe/Near East
and Central Africa.
vertebrae. This may have caused lordosis (the normal curvature of the human spine) and moved the center of mass over the hips and legs, which implies some habitual bipedal activity.The regions you describe above are part of the Mediterranean coastalI acknowledge the facts you describe above. However, the Levant is
savannah and desert except for a narrow strip along the Mediterranean >> >> and up in the mountains. While this is no problem for terrestrial
bipeds like Homo, ISTM arboreal hominids like D.guggenmosi would have >> >> a much harder time living/migrating there.
"is".
Again, refer to microclimate of Levant 11ma - 5ma. Today's Dead Sea was once the vast brackish Lake Lisan that reached to Lebanon, a gallery forest may have reached from Anatolia to Egypt.
mountains I mentioned previously.
The Dead Sea is by no means a coastal mountain region. https://en.wikipedia.org/wiki/Judaean_Mountains
These are part of a series of ranges all along the eastern
Mediterranean coast.
I agree a coastal Mediterranean
forest is plausible.
I'm referring to the tectonic rift valley between Zimbabwe/Zambia and Lebanon/Anatolia.... which runs parallel to the Mediterranean coast.
Of course, there were coastal forests as well, but they were affected by the MSC.
However, my understanding is the evidence is
insufficient to say if it would have been as extensive and continuous
as you suggest during the time you suggest.
Haven't got enough hard data yet.Cite the data you think is sufficient to answer this question.
What is ISTM?
It's shorthand acronym for "It Seems To Me"
Ok, thanks.
Danuvius, Rudapithecus, Graecopithecus, Oranopithecus each had a unique trait shared with hominins. I think of them as a superspecies with local variations.-
If you place Danuvius half-way between fast brachiating bipedal long backed long achilles tendon hylobatids and bipedal Homo with long back and long achilles tendon, it fits perfectly.
Wiki:
Danuvius is thought to have had a broad chest. It is the first recorded Miocene great ape to have had the diaphragm located in the lower chest cavity, as in Homo, indicating an extended lower back and a greater number of functional lumbar
ankle loading, and the ankle would have had a hinge-like function, being most stable if positioned perpendicularly to the leg as opposed to at an angle in apes. Danuvius was likely able to achieve a strong grip with its big toes, unlike modern African
The robust finger and hypertrophied wrist and elbow bones indicate a strong grip and load bearing adaptations for the arms. The legs also show adaptations for load-bearing, especially at the hypertrophied knee joint. There was likely limited
On Saturday, November 19, 2022 at 6:40:01 AM UTC-5, 69jp...@gmail.com wrote: >> On Fri, 18 Nov 2022 03:45:32 -0800 (PST), Daud Deden
<daud....@gmail.com> wrote:
On Friday, November 18, 2022 at 2:12:32 AM UTC-5, 69jp...@gmail.com wrote: >> >> On Thu, 17 Nov 2022 15:53:51 -0800 (PST), Daud DedenThe positions of the muzzle and/or nose relative to the foramen magnum
<daud....@gmail.com> wrote:
On Thursday, November 17, 2022 at 12:57:57 PM UTC-5, 69jp...@gmail.com wrote:My understanding is the relative position of foramen magnum doesn't
On Wed, 16 Nov 2022 22:42:03 -0800 (PST), Daud Deden
<daud....@gmail.com> wrote:
On Thursday, November 17, 2022 at 1:29:04 AM UTC-5, Daud Deden wrote:Not sure what you mean by "mature"; the individual or the species?
On Wednesday, November 16, 2022 at 11:08:11 AM UTC-5, 69jp...@gmail.com wrote:
On Fri, 04 Nov 2022 02:21:55 -0400, jillery <69jp...@gmail.com> >> >> >> >> > wrote:
On Thu, 3 Nov 2022 20:32:40 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Thursday, November 3, 2022 at 6:29:01 PM UTC-4, 69jp...@gmail.com wrote:
On Thu, 3 Nov 2022 07:56:05 -0700 (PDT), Daud DedenYes, I claim it is *descended from* European Miocene apes of the Black Sea region.
<daud....@gmail.com> wrote:
On Tuesday, November 1, 2022 at 4:17:31 AM UTC-4, 69jp...@gmail.com wrote:Sahelanthropus tchadensis is neither Miocene nor European, but is a
On Mon, 31 Oct 2022 15:15:01 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Monday, October 24, 2022 at 2:50:22 AM UTC-4, 69jp...@gmail.com wrote:Thank you for citing the above video. It's prelude to the ones I
Gutsick Gibbon is the Youtube handle of a biological anthropology PhD-
student named Eriks. Two of her recent videos discuss some of the
latest developments relating to the origins of human bipedalism:
<https://www.youtube.com/watch?v=kbQAgPSHbZE>
The above is a link to a 32-minute video where Erika discusses several
papers relating to Sahelanthropus tchadensis. This fossil is
remarkable in part because it's dated to about 7mya and was found in
central-african Chad, and also because it may be the oldest bipedal
hominin fossil found to date. However, there appears to be strong
disagreement whether the evidence supports bipedalism. >> >> >> >> > >>> >> >>
<https://www.youtube.com/watch?v=Nwkfkp360ps>
The above is a link to a 22-minute video where Erika discusses several
hypotheses about *why* our ancestors shifted to obligate bipedalism.
She discusses several hypotheses, and presents compelling arguments
for her preferred one.
Video by Erika on Lucy bipedalism: https://youtu.be/jo2ZLnucuHY
cited, and refers to them, and so complete a logical trilogy.
In another video, she says that Sahelanthropus was the LCA of Homo / Pan, (though probably just in the general sense). https://www.youtube.com/watch?v=g4FTbZLkpzU&t=7s
In my view, Sahelanthropus is just a southwestern European Miocene ape *Descendant*, very similar to their eastern and northern kin. I see nothing palmigrade in any Miocene ape.
Pliocene central African species.
My impression is there isn't enough evidence to show whether Pliocene
African apes descended from Miocene European apes or Miocene African
apes. Either way, there was enough time between the two eras to have
evolved differences between either Miocene populations and Pliocene S.
tchadensis.
I have recently become aware of:
<https://en.wikipedia.org/wiki/Danuvius_guggenmosi>
which was a Miocene European ape that may have evolved arboreal >> >> >> >> > bipedalism similar to S.tchadensis.
Depending on how widespread its range, and how successful its
descendants, it's plausible they lived south of the Black Sea during
the late Miocene.
The question then becomes whether it's more likely these apes found
their way into Africa to become the ancestors of Pliocene
S.tchadensis, or whether S.tchadensis evolved from Miocene African
apes.
Unfortunately, the habitat of these apes made their fossil
preservation extremely rare, and so the evidence to well support >> >> >> >> > either hypothesis is lacking.
However, the question at least conditionally can be answered by >> >> >> >> > comparing the likelihood of a migratory pathway during that time,
versus the likelihood of arboreal bipedalism evolving independently in
two populations.
There are a number of anatomic features associated with arboreal >> >> >> >> > bipedalism, some of which are necessary, ex. anterior foramen magnum,
The foramen magnum is always situated relatively more anteriorly in immature than in mature apes.[ - and men. ]
Individually.
change significantly during human development.
Right. In chimps the muzzle gradually moves anteriorly relative to the foramen magnum, in Homo only the nose does.
Sorry, I erred above, I'd meant "...than in mature apes." The "and men" was NOT meant, I thought I'd erased it! Oops.
don't inform bipedalism.
It does, in tail-less upright orthogonal striding terrestrial former/partial arboreal bipeds, it does not in hopping bipeds.
Cf short-faced giant kangaroo (short tail, striding upright bipedal)
How is that an exceptional case among hominins? Only Usain Bolt can outrun qpal chimp at top speed.Imagine how much faster that person would be if he ran normally, likeAll Homo species are great apes by definition, including H.sapiens.Either way, the important point is the position and angle of foramen >> >> >> magnum are diagnostic among all vertebrates for how they habitually >> >> >> hold their head, and so includes/excludes bipedalism among hominids. >> >> >Yes, but no. Great apes are bipedal except when (hurrying) on open ground they adopt quadrupedalism. Homo retains the primitive bipedal gait of hominoid ancestors, as do hylobatids.
Yes, I meant 'arboreal great apes'. Humans are terrestrial great apes, hylobatids are arboreal lesser apes.
They do/did quadrupedalism only in exceptional cases.
https://youtu.be/pCrH6BOwxe4 15mph qpal running as a patas monkey, not a chimp.
this:
<https://www.youtube.com/watch?v=k3PZgbQ8auE>
That's not my understanding. My understanding is chimpanzees,Perhaps. My understanding is bipedal arboreal apes continued to walk... and wet aka tropical,and some of which are incidental, ex. molar patterns. Descendant >> >> >> >> > populations are more likely to share these features than areCentral Africa is and was hot,
independent populations. This suggests to me that a sufficiently >> >> >> >> > robust fossil record could answer this question with some degree of
certainty.
Alternately, my understanding is southern Europe and central Africa
are ecological opposites, in the sense that when one is hot and dry
the other is temperate and wet.
The adoption of qpal knucklewalking by African apes indicates that their ancient habitat went through a dry phase (rainforest became patchy) forcing a terrestrial dog-like gait.
bipedally on the ground, while non-bipedal arboreal apes also adopted
quadrupedal habits on the ground.
Bipedal walking is primitive in arboreal hominoids, quadrupedal walking is derived. I don't know of any 'non-bipedal arboreal apes', only monkeys.
gorillas, and orangutans are non-bipedal arboreal apes, meaning when
they are in the trees, they do not walk upright.
Their body orientation on and under branches is primarily upright, not pronograde with all limbs in compression aka quadrupedal. The modern AMHs orthogonal posture is derived, not the same as primitive upright bipedal arboreal hominoids.
As were most
arboreal apes prior to Australopithecines.
<https://www.britannica.com/place/Black-Sea/Climate>Again perhaps. It also suggests small bipedal arboreal apes werejust right for the evolution of small bipedal arboreal apes.
The fact that there are no small bipedal arboreal apes in Africa indicates that there was some climate shifting.
outcompeted.
They were, by monkeys which were more ground adapted, able to swiftly run between forest stands during a drier climate phase.
The relative position of the Black Sea didn't change from then to now. >> >> The important point is its position is deep in Eurasia, wherethe southern Black Sea is between temperate and tropical.Correct. Southern Europe and the Black Sea are at the same latitudes. >> >> >> This suggests they would tend to have the same climate. However, the >> >> >> Black Sea is farther inland, and so suffers more continental extremes.
So any climate changes will appear first around the Black Sea and
become more extreme compared to southern Europe.
I'm talking about from 11ma through the MSC to 5ma. The Medit. & Red Seas dried out, the Black Sea didn't.
continental climates rule.
It lies between the Atlantic-Mediterranean and the Caspian Sea, in the Peri-Tethyan basin, protected by the high Iranian plateau to the south. Not a typical continental climate.
**********************************
The climate of the landlocked Black Sea can be characterized generally
as continental (i.e., subject to pronounced seasonal temperature
variations), although climatic conditions in some parts of the basin
are controlled to a great extent by the shoreline relief. A steppe
climate, with cold winters and hot, dry summers, is found in the
northwestern part of the basin exposed to the influence of air masses
from the north.
************************************
Summer in north including Bavaria via Danube valley, winter in south including visits further southwardly.
I acknowledge that rift was one plausible pathway from Europe toMy understanding is the Mediterranean dried out only about 6mya, long
after European, and presumably Black Sea, arboreal apes went extinct.
No, Danuvius and later Miocene apes there were of one lineage IMO, that may have lived there until 5ma, with successive expansional waves emigrating outwardly including towards Africa.
The Red Sea is too far south to affect migration from Europe to Africa >> >> regardless of climate patterns.
It is part of the African-Anatolian rift.
Africa. The Red Sea was not, nor did it block such a pathway.
I include it provisionally, more data needed.
No, I am speaking of climate then *and* now. Regions around 30Moving toward 30 degrees latitude, rainfall becomes seasonally dry, >> >> >> and then almost continuously dry. My understanding is, the only
native forests south of the Caspian are in the mountains, and adjacent
to the Mediterranean coasts. Arboreal apes of any kind would find
these deserts impassible.
You are speaking of recent climate. There are no arboreal apes there now.
degrees latitude tend to be drier than those around the equator, with
exceptions due to terrain and ocean currents.
Stop temporarily.
known cooking (fish .78ma) and earliest waternut gathering and bread making. The region is amenable to hominins & Homo.You appear to be claiming that the European Miocene apes could never have been linked to African and Asian apes. Yet they certainly were, else they wouldn't have existed at all.Such an "appearance" is incorrect. In certain cases, regions around
30 degrees latitude have/had enough rainfall to support forests. The
relevant point here is, global climate since the Miocene has gotten
colder and drier, especially around 30 degrees latitude, which has led
to the creation of large areas of treeless savannah and desert. I
don't know when European and African forests separated. Do you?
Also, the question isn't about the origin of apes generally. It's
about the origin of arboreal bipedal apes. We know they existed in
Pliocene Africa. They *may* have existed in Miocene Europe. Even if
they did, the two populations may still have evolved independently.
To a first approximation, average rainfall and temperature are
functions of latitude. However, while temperature is a function of
the sine of latitude, rainfall is more complex. It tends to be
continuously heavy near the equator, continuously dry near 30 degrees,
and seasonally variable between 30 and 60 degrees. This general
pattern is modified, sometimes dramatically, by terrain, ocean
currents, seasons, and Milankovitch cycles.
The most significant variable is Africa's northward tectonic
migration, about a centimeter a year since before the Miocene. So,
while central Africa has moved from south to north of the equator with
little effect, north Africa has approached and then went north of 30 >> >> >> degrees, making it over time ever drier, amplifying other climate
trends, making once wooded areas into vast savannah and desert.
Yes.
Also, Africa's tectonic slide north almost certainly pinched closed >> >> >> the Gilbraltar Sttraits, which caused the Mediterranean to dry up at >> >> >> least once, and likely several times as sea levels rose and fell. The >> >> >> resulting hot salt basin would also have been impassible for arboreal >> >> >> apes.
This is as true now as it was in theI would not claim nor disclaim that. The Levant is near the midpoint, extends the African Rift valley to Anatolia, is a major avian migration route between Africa and Eurasia, has fossil/artifacts of Homo erectus, neanderthal & sapiens oldest
Miocene. This suggests to me there could not have been an unbroken
forested path for arboreal apes to migrate between Europe/Near East
and Central Africa.
vertebrae. This may have caused lordosis (the normal curvature of the human spine) and moved the center of mass over the hips and legs, which implies some habitual bipedal activity.https://en.wikipedia.org/wiki/Judaean_MountainsThe regions you describe above are part of the Mediterranean coastalI acknowledge the facts you describe above. However, the Levant is
savannah and desert except for a narrow strip along the Mediterranean >> >> >> and up in the mountains. While this is no problem for terrestrial
bipeds like Homo, ISTM arboreal hominids like D.guggenmosi would have >> >> >> a much harder time living/migrating there.
"is".
Again, refer to microclimate of Levant 11ma - 5ma. Today's Dead Sea was once the vast brackish Lake Lisan that reached to Lebanon, a gallery forest may have reached from Anatolia to Egypt.
mountains I mentioned previously.
The Dead Sea is by no means a coastal mountain region.
These are part of a series of ranges all along the eastern
Mediterranean coast.
... which runs parallel to the Mediterranean coast.I agree a coastal Mediterranean
forest is plausible.
I'm referring to the tectonic rift valley between Zimbabwe/Zambia and Lebanon/Anatolia.
Of course, there were coastal forests as well, but they were affected by the MSC.Cite the data you think is sufficient to answer this question.
However, my understanding is the evidence is
insufficient to say if it would have been as extensive and continuous
as you suggest during the time you suggest.
Haven't got enough hard data yet.
What is ISTM?
It's shorthand acronym for "It Seems To Me"
Ok, thanks.
Danuvius, Rudapithecus, Graecopithecus, Oranopithecus each had a unique trait shared with hominins. I think of them as a superspecies with local variations.-
If you place Danuvius half-way between fast brachiating bipedal long backed long achilles tendon hylobatids and bipedal Homo with long back and long achilles tendon, it fits perfectly.
Wiki:
Danuvius is thought to have had a broad chest. It is the first recorded Miocene great ape to have had the diaphragm located in the lower chest cavity, as in Homo, indicating an extended lower back and a greater number of functional lumbar
ankle loading, and the ankle would have had a hinge-like function, being most stable if positioned perpendicularly to the leg as opposed to at an angle in apes. Danuvius was likely able to achieve a strong grip with its big toes, unlike modern African
The robust finger and hypertrophied wrist and elbow bones indicate a strong grip and load bearing adaptations for the arms. The legs also show adaptations for load-bearing, especially at the hypertrophied knee joint. There was likely limited
On Sat, 19 Nov 2022 06:06:22 -0800 (PST), Daud Deden
<daud....@gmail.com> wrote:
On Saturday, November 19, 2022 at 6:40:01 AM UTC-5, 69jp...@gmail.com wrote:
On Fri, 18 Nov 2022 03:45:32 -0800 (PST), Daud Deden
<daud....@gmail.com> wrote:
On Friday, November 18, 2022 at 2:12:32 AM UTC-5, 69jp...@gmail.com wrote:The positions of the muzzle and/or nose relative to the foramen magnum
On Thu, 17 Nov 2022 15:53:51 -0800 (PST), Daud Deden
<daud....@gmail.com> wrote:
On Thursday, November 17, 2022 at 12:57:57 PM UTC-5, 69jp...@gmail.com wrote:My understanding is the relative position of foramen magnum doesn't
On Wed, 16 Nov 2022 22:42:03 -0800 (PST), Daud DedenIndividually.
<daud....@gmail.com> wrote:
On Thursday, November 17, 2022 at 1:29:04 AM UTC-5, Daud Deden wrote:Not sure what you mean by "mature"; the individual or the species? >> >> >
On Wednesday, November 16, 2022 at 11:08:11 AM UTC-5, 69jp...@gmail.com wrote:
On Fri, 04 Nov 2022 02:21:55 -0400, jillery <69jp...@gmail.com>
wrote:
On Thu, 3 Nov 2022 20:32:40 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Thursday, November 3, 2022 at 6:29:01 PM UTC-4, 69jp...@gmail.com wrote:
On Thu, 3 Nov 2022 07:56:05 -0700 (PDT), Daud DedenYes, I claim it is *descended from* European Miocene apes of the Black Sea region.
<daud....@gmail.com> wrote:
On Tuesday, November 1, 2022 at 4:17:31 AM UTC-4, 69jp...@gmail.com wrote:Sahelanthropus tchadensis is neither Miocene nor European, but is a
On Mon, 31 Oct 2022 15:15:01 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Monday, October 24, 2022 at 2:50:22 AM UTC-4, 69jp...@gmail.com wrote:Thank you for citing the above video. It's prelude to the ones I
Gutsick Gibbon is the Youtube handle of a biological anthropology PhD-
student named Eriks. Two of her recent videos discuss some of the
latest developments relating to the origins of human bipedalism:
<https://www.youtube.com/watch?v=kbQAgPSHbZE>
The above is a link to a 32-minute video where Erika discusses several
papers relating to Sahelanthropus tchadensis. This fossil is
remarkable in part because it's dated to about 7mya and was found in
central-african Chad, and also because it may be the oldest bipedal
hominin fossil found to date. However, there appears to be strong
disagreement whether the evidence supports bipedalism.
<https://www.youtube.com/watch?v=Nwkfkp360ps>
The above is a link to a 22-minute video where Erika discusses several
hypotheses about *why* our ancestors shifted to obligate bipedalism.
She discusses several hypotheses, and presents compelling arguments
for her preferred one.
Video by Erika on Lucy bipedalism: https://youtu.be/jo2ZLnucuHY
cited, and refers to them, and so complete a logical trilogy.
In another video, she says that Sahelanthropus was the LCA of Homo / Pan, (though probably just in the general sense). https://www.youtube.com/watch?v=g4FTbZLkpzU&t=7s
In my view, Sahelanthropus is just a southwestern European Miocene ape *Descendant*, very similar to their eastern and northern kin. I see nothing palmigrade in any Miocene ape.
Pliocene central African species.
My impression is there isn't enough evidence to show whether Pliocene
African apes descended from Miocene European apes or Miocene African
apes. Either way, there was enough time between the two eras to have
evolved differences between either Miocene populations and Pliocene S.
tchadensis.
I have recently become aware of:
<https://en.wikipedia.org/wiki/Danuvius_guggenmosi>
which was a Miocene European ape that may have evolved arboreal
bipedalism similar to S.tchadensis.
Depending on how widespread its range, and how successful its >> >> >> >> > descendants, it's plausible they lived south of the Black Sea during
the late Miocene.
The question then becomes whether it's more likely these apes found
their way into Africa to become the ancestors of Pliocene
S.tchadensis, or whether S.tchadensis evolved from Miocene African
apes.
Unfortunately, the habitat of these apes made their fossil
preservation extremely rare, and so the evidence to well support
either hypothesis is lacking.
However, the question at least conditionally can be answered by
comparing the likelihood of a migratory pathway during that time,
versus the likelihood of arboreal bipedalism evolving independently in
two populations.
There are a number of anatomic features associated with arboreal
bipedalism, some of which are necessary, ex. anterior foramen magnum,
The foramen magnum is always situated relatively more anteriorly in immature than in mature apes.[ - and men. ]
change significantly during human development.
Right. In chimps the muzzle gradually moves anteriorly relative to the foramen magnum, in Homo only the nose does.
Sorry, I erred above, I'd meant "...than in mature apes." The "and men" was NOT meant, I thought I'd erased it! Oops.
don't inform bipedalism.
It does, in tail-less upright orthogonal striding terrestrial former/partial arboreal bipeds, it does not in hopping bipeds.The topic isn't general bipedalism, but hominoid bipedalism.
Cf short-faced giant kangaroo (short tail, striding upright bipedal)
Non-hominoid species don't inform this discussion.
Your cited video shows an exceptional case among humans, which have relatively short arms and long legs, anatomically maladapted forHow is that an exceptional case among hominins? Only Usain Bolt can outrun qpal chimp at top speed.Imagine how much faster that person would be if he ran normally, likeAll Homo species are great apes by definition, including H.sapiens.Either way, the important point is the position and angle of foramen
magnum are diagnostic among all vertebrates for how they habitually >> >> >> hold their head, and so includes/excludes bipedalism among hominids.
Yes, but no. Great apes are bipedal except when (hurrying) on open ground they adopt quadrupedalism. Homo retains the primitive bipedal gait of hominoid ancestors, as do hylobatids.
Yes, I meant 'arboreal great apes'. Humans are terrestrial great apes, hylobatids are arboreal lesser apes.
They do/did quadrupedalism only in exceptional cases.
https://youtu.be/pCrH6BOwxe4 15mph qpal running as a patas monkey, not a chimp.
this:
<https://www.youtube.com/watch?v=k3PZgbQ8auE>
quadrupedal locomotion. Also, even though his head is in extreme
elevation, he can barely see where he's going, as his foramen magnum
is anatomically maladapted for quadrupedal motion. Silly Guinness
records notwithstanding, any human moving quadrupedally from a
predator would soon become predator poop.
That's not my understanding. My understanding is chimpanzees,Perhaps. My understanding is bipedal arboreal apes continued to walk >> >> bipedally on the ground, while non-bipedal arboreal apes also adopted >> >> quadrupedal habits on the ground.... and wet aka tropical,and some of which are incidental, ex. molar patterns. DescendantCentral Africa is and was hot,
populations are more likely to share these features than are >> >> >> >> > independent populations. This suggests to me that a sufficiently
robust fossil record could answer this question with some degree of
certainty.
Alternately, my understanding is southern Europe and central Africa
are ecological opposites, in the sense that when one is hot and dry
the other is temperate and wet.
The adoption of qpal knucklewalking by African apes indicates that their ancient habitat went through a dry phase (rainforest became patchy) forcing a terrestrial dog-like gait.
Bipedal walking is primitive in arboreal hominoids, quadrupedal walking is derived. I don't know of any 'non-bipedal arboreal apes', only monkeys.
gorillas, and orangutans are non-bipedal arboreal apes, meaning when
they are in the trees, they do not walk upright.
Their body orientation on and under branches is primarily upright, not pronograde with all limbs in compression aka quadrupedal. The modern AMHs orthogonal posture is derived, not the same as primitive upright bipedal arboreal hominoids.You continue to use above a non-standard meaning of bipedalism.
Hanging from branches using combinations of limbs isn't bipedalism any
more than is climbing up coconut palms.
As were most
arboreal apes prior to Australopithecines.
<https://www.britannica.com/place/Black-Sea/Climate>Again perhaps. It also suggests small bipedal arboreal apes werejust right for the evolution of small bipedal arboreal apes.
The fact that there are no small bipedal arboreal apes in Africa indicates that there was some climate shifting.
outcompeted.
They were, by monkeys which were more ground adapted, able to swiftly run between forest stands during a drier climate phase.
The relative position of the Black Sea didn't change from then to now. >> >> The important point is its position is deep in Eurasia, wherethe southern Black Sea is between temperate and tropical.Correct. Southern Europe and the Black Sea are at the same latitudes.
This suggests they would tend to have the same climate. However, the
Black Sea is farther inland, and so suffers more continental extremes.
So any climate changes will appear first around the Black Sea and >> >> >> become more extreme compared to southern Europe.
I'm talking about from 11ma through the MSC to 5ma. The Medit. & Red Seas dried out, the Black Sea didn't.
continental climates rule.
It lies between the Atlantic-Mediterranean and the Caspian Sea, in the Peri-Tethyan basin, protected by the high Iranian plateau to the south. Not a typical continental climate.
**********************************
The climate of the landlocked Black Sea can be characterized generally
as continental (i.e., subject to pronounced seasonal temperature
variations), although climatic conditions in some parts of the basin
are controlled to a great extent by the shoreline relief. A steppe
climate, with cold winters and hot, dry summers, is found in the
northwestern part of the basin exposed to the influence of air masses
from the north.
************************************
Summer in north including Bavaria via Danube valley, winter in south including visits further southwardly.I suppose Miocene apes collected frequent-flier miles.
I acknowledge that rift was one plausible pathway from Europe toMy understanding is the Mediterranean dried out only about 6mya, long >> >> after European, and presumably Black Sea, arboreal apes went extinct. >> >No, Danuvius and later Miocene apes there were of one lineage IMO, that may have lived there until 5ma, with successive expansional waves emigrating outwardly including towards Africa.
The Red Sea is too far south to affect migration from Europe to Africa >> >> regardless of climate patterns.
It is part of the African-Anatolian rift.
Africa. The Red Sea was not, nor did it block such a pathway.
I include it provisionally, more data needed.Sounds like a segue for aquatic ape hypothesis.
No, I am speaking of climate then *and* now. Regions around 30Moving toward 30 degrees latitude, rainfall becomes seasonally dry, >> >> >> and then almost continuously dry. My understanding is, the only
native forests south of the Caspian are in the mountains, and adjacent
to the Mediterranean coasts. Arboreal apes of any kind would find >> >> >> these deserts impassible.
You are speaking of recent climate. There are no arboreal apes there now.
degrees latitude tend to be drier than those around the equator, with >> >> exceptions due to terrain and ocean currents.
Stop temporarily.
Unclear. Do you mean stop migration temporarily? If so, keep in mindoldest known cooking (fish .78ma) and earliest waternut gathering and bread making. The region is amenable to hominins & Homo.
that the same climate changes which would create arid conditions
around 30 degrees latitude would also shrink forests further north and south.
You appear to be claiming that the European Miocene apes could never have been linked to African and Asian apes. Yet they certainly were, else they wouldn't have existed at all.Such an "appearance" is incorrect. In certain cases, regions around
30 degrees latitude have/had enough rainfall to support forests. The
relevant point here is, global climate since the Miocene has gotten
colder and drier, especially around 30 degrees latitude, which has led
to the creation of large areas of treeless savannah and desert. I
don't know when European and African forests separated. Do you?
Also, the question isn't about the origin of apes generally. It's
about the origin of arboreal bipedal apes. We know they existed in
Pliocene Africa. They *may* have existed in Miocene Europe. Even if
they did, the two populations may still have evolved independently.
To a first approximation, average rainfall and temperature are
functions of latitude. However, while temperature is a function of >> >> >> the sine of latitude, rainfall is more complex. It tends to be
continuously heavy near the equator, continuously dry near 30 degrees,
and seasonally variable between 30 and 60 degrees. This general
pattern is modified, sometimes dramatically, by terrain, ocean
currents, seasons, and Milankovitch cycles.
The most significant variable is Africa's northward tectonic
migration, about a centimeter a year since before the Miocene. So, >> >> >> while central Africa has moved from south to north of the equator with
little effect, north Africa has approached and then went north of 30
degrees, making it over time ever drier, amplifying other climate >> >> >> trends, making once wooded areas into vast savannah and desert.
Yes.
Also, Africa's tectonic slide north almost certainly pinched closed >> >> >> the Gilbraltar Sttraits, which caused the Mediterranean to dry up at
least once, and likely several times as sea levels rose and fell. The
resulting hot salt basin would also have been impassible for arboreal
apes.
This is as true now as it was in theI would not claim nor disclaim that. The Levant is near the midpoint, extends the African Rift valley to Anatolia, is a major avian migration route between Africa and Eurasia, has fossil/artifacts of Homo erectus, neanderthal & sapiens
Miocene. This suggests to me there could not have been an unbroken
forested path for arboreal apes to migrate between Europe/Near East
and Central Africa.
vertebrae. This may have caused lordosis (the normal curvature of the human spine) and moved the center of mass over the hips and legs, which implies some habitual bipedal activity.https://en.wikipedia.org/wiki/Judaean_MountainsThe regions you describe above are part of the Mediterranean coastal >> >> mountains I mentioned previously.I acknowledge the facts you describe above. However, the Levant is >> >> >> savannah and desert except for a narrow strip along the Mediterranean
and up in the mountains. While this is no problem for terrestrial >> >> >> bipeds like Homo, ISTM arboreal hominids like D.guggenmosi would have
a much harder time living/migrating there.
"is".
Again, refer to microclimate of Levant 11ma - 5ma. Today's Dead Sea was once the vast brackish Lake Lisan that reached to Lebanon, a gallery forest may have reached from Anatolia to Egypt.
The Dead Sea is by no means a coastal mountain region.
These are part of a series of ranges all along the eastern
Mediterranean coast.
... which runs parallel to the Mediterranean coast.I agree a coastal Mediterranean
forest is plausible.
I'm referring to the tectonic rift valley between Zimbabwe/Zambia and Lebanon/Anatolia.
Of course, there were coastal forests as well, but they were affected by the MSC.Cite the data you think is sufficient to answer this question.
However, my understanding is the evidence is
insufficient to say if it would have been as extensive and continuous >> >> as you suggest during the time you suggest.
Haven't got enough hard data yet.
What is ISTM?
It's shorthand acronym for "It Seems To Me"
Ok, thanks.
Danuvius, Rudapithecus, Graecopithecus, Oranopithecus each had a unique trait shared with hominins. I think of them as a superspecies with local variations.-
If you place Danuvius half-way between fast brachiating bipedal long backed long achilles tendon hylobatids and bipedal Homo with long back and long achilles tendon, it fits perfectly.
Wiki:
Danuvius is thought to have had a broad chest. It is the first recorded Miocene great ape to have had the diaphragm located in the lower chest cavity, as in Homo, indicating an extended lower back and a greater number of functional lumbar
ankle loading, and the ankle would have had a hinge-like function, being most stable if positioned perpendicularly to the leg as opposed to at an angle in apes. Danuvius was likely able to achieve a strong grip with its big toes, unlike modern African
The robust finger and hypertrophied wrist and elbow bones indicate a strong grip and load bearing adaptations for the arms. The legs also show adaptations for load-bearing, especially at the hypertrophied knee joint. There was likely limited
On Sat, 19 Nov 2022 06:06:22 -0800 (PST), Daud Deden
<daud....@gmail.com> wrote:
On Saturday, November 19, 2022 at 6:40:01 AM UTC-5, 69jp...@gmail.com wrote:
On Fri, 18 Nov 2022 03:45:32 -0800 (PST), Daud Deden
<daud....@gmail.com> wrote:
On Friday, November 18, 2022 at 2:12:32 AM UTC-5, 69jp...@gmail.com wrote:The positions of the muzzle and/or nose relative to the foramen magnum
On Thu, 17 Nov 2022 15:53:51 -0800 (PST), Daud Deden
<daud....@gmail.com> wrote:
On Thursday, November 17, 2022 at 12:57:57 PM UTC-5, 69jp...@gmail.com wrote:My understanding is the relative position of foramen magnum doesn't
On Wed, 16 Nov 2022 22:42:03 -0800 (PST), Daud DedenIndividually.
<daud....@gmail.com> wrote:
On Thursday, November 17, 2022 at 1:29:04 AM UTC-5, Daud Deden wrote:Not sure what you mean by "mature"; the individual or the species? >> >> >
On Wednesday, November 16, 2022 at 11:08:11 AM UTC-5, 69jp...@gmail.com wrote:
On Fri, 04 Nov 2022 02:21:55 -0400, jillery <69jp...@gmail.com>
wrote:
On Thu, 3 Nov 2022 20:32:40 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Thursday, November 3, 2022 at 6:29:01 PM UTC-4, 69jp...@gmail.com wrote:
On Thu, 3 Nov 2022 07:56:05 -0700 (PDT), Daud DedenYes, I claim it is *descended from* European Miocene apes of the Black Sea region.
<daud....@gmail.com> wrote:
On Tuesday, November 1, 2022 at 4:17:31 AM UTC-4, 69jp...@gmail.com wrote:Sahelanthropus tchadensis is neither Miocene nor European, but is a
On Mon, 31 Oct 2022 15:15:01 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Monday, October 24, 2022 at 2:50:22 AM UTC-4, 69jp...@gmail.com wrote:Thank you for citing the above video. It's prelude to the ones I
Gutsick Gibbon is the Youtube handle of a biological anthropology PhD-
student named Eriks. Two of her recent videos discuss some of the
latest developments relating to the origins of human bipedalism:
<https://www.youtube.com/watch?v=kbQAgPSHbZE>
The above is a link to a 32-minute video where Erika discusses several
papers relating to Sahelanthropus tchadensis. This fossil is
remarkable in part because it's dated to about 7mya and was found in
central-african Chad, and also because it may be the oldest bipedal
hominin fossil found to date. However, there appears to be strong
disagreement whether the evidence supports bipedalism.
<https://www.youtube.com/watch?v=Nwkfkp360ps>
The above is a link to a 22-minute video where Erika discusses several
hypotheses about *why* our ancestors shifted to obligate bipedalism.
She discusses several hypotheses, and presents compelling arguments
for her preferred one.
Video by Erika on Lucy bipedalism: https://youtu.be/jo2ZLnucuHY
cited, and refers to them, and so complete a logical trilogy.
In another video, she says that Sahelanthropus was the LCA of Homo / Pan, (though probably just in the general sense). https://www.youtube.com/watch?v=g4FTbZLkpzU&t=7s
In my view, Sahelanthropus is just a southwestern European Miocene ape *Descendant*, very similar to their eastern and northern kin. I see nothing palmigrade in any Miocene ape.
Pliocene central African species.
My impression is there isn't enough evidence to show whether Pliocene
African apes descended from Miocene European apes or Miocene African
apes. Either way, there was enough time between the two eras to have
evolved differences between either Miocene populations and Pliocene S.
tchadensis.
I have recently become aware of:
<https://en.wikipedia.org/wiki/Danuvius_guggenmosi>
which was a Miocene European ape that may have evolved arboreal
bipedalism similar to S.tchadensis.
Depending on how widespread its range, and how successful its >> >> >> >> > descendants, it's plausible they lived south of the Black Sea during
the late Miocene.
The question then becomes whether it's more likely these apes found
their way into Africa to become the ancestors of Pliocene
S.tchadensis, or whether S.tchadensis evolved from Miocene African
apes.
Unfortunately, the habitat of these apes made their fossil
preservation extremely rare, and so the evidence to well support
either hypothesis is lacking.
However, the question at least conditionally can be answered by
comparing the likelihood of a migratory pathway during that time,
versus the likelihood of arboreal bipedalism evolving independently in
two populations.
There are a number of anatomic features associated with arboreal
bipedalism, some of which are necessary, ex. anterior foramen magnum,
The foramen magnum is always situated relatively more anteriorly in immature than in mature apes.[ - and men. ]
change significantly during human development.
Right. In chimps the muzzle gradually moves anteriorly relative to the foramen magnum, in Homo only the nose does.
Sorry, I erred above, I'd meant "...than in mature apes." The "and men" was NOT meant, I thought I'd erased it! Oops.
don't inform bipedalism.
It does, in tail-less upright orthogonal striding terrestrial former/partial arboreal bipeds, it does not in hopping bipeds.The topic isn't general bipedalism, but hominoid bipedalism.
Cf short-faced giant kangaroo (short tail, striding upright bipedal)
Non-hominoid species don't inform this discussion.
Your cited video shows an exceptional case among humans, which have relatively short arms and long legs, anatomically maladapted forHow is that an exceptional case among hominins? Only Usain Bolt can outrun qpal chimp at top speed.Imagine how much faster that person would be if he ran normally, likeAll Homo species are great apes by definition, including H.sapiens.Either way, the important point is the position and angle of foramen
magnum are diagnostic among all vertebrates for how they habitually >> >> >> hold their head, and so includes/excludes bipedalism among hominids.
Yes, but no. Great apes are bipedal except when (hurrying) on open ground they adopt quadrupedalism. Homo retains the primitive bipedal gait of hominoid ancestors, as do hylobatids.
Yes, I meant 'arboreal great apes'. Humans are terrestrial great apes, hylobatids are arboreal lesser apes.
They do/did quadrupedalism only in exceptional cases.
https://youtu.be/pCrH6BOwxe4 15mph qpal running as a patas monkey, not a chimp.
this:
<https://www.youtube.com/watch?v=k3PZgbQ8auE>
quadrupedal locomotion.
elevation, he can barely see where he's going, as his foramen magnum
is anatomically maladapted for quadrupedal motion. Silly Guinness
records notwithstanding, any human moving quadrupedally from a
predator would soon become predator poop.
That's not my understanding. My understanding is chimpanzees,Perhaps. My understanding is bipedal arboreal apes continued to walk >> >> bipedally on the ground, while non-bipedal arboreal apes also adopted >> >> quadrupedal habits on the ground.... and wet aka tropical,and some of which are incidental, ex. molar patterns. DescendantCentral Africa is and was hot,
populations are more likely to share these features than are >> >> >> >> > independent populations. This suggests to me that a sufficiently
robust fossil record could answer this question with some degree of
certainty.
Alternately, my understanding is southern Europe and central Africa
are ecological opposites, in the sense that when one is hot and dry
the other is temperate and wet.
The adoption of qpal knucklewalking by African apes indicates that their ancient habitat went through a dry phase (rainforest became patchy) forcing a terrestrial dog-like gait.
Bipedal walking is primitive in arboreal hominoids, quadrupedal walking is derived. I don't know of any 'non-bipedal arboreal apes', only monkeys.
gorillas, and orangutans are non-bipedal arboreal apes, meaning when
they are in the trees, they do not walk upright.
Their body orientation on and under branches is primarily upright, not pronograde with all limbs in compression aka quadrupedal. The modern AMHs orthogonal posture is derived, not the same as primitive upright bipedal arboreal hominoids.You continue to use above a non-standard meaning of bipedalism.
Hanging from branches using combinations of limbs isn't bipedalism any
more than is climbing up coconut palms.
They weren't sessile, but very mobile.As were most
arboreal apes prior to Australopithecines.
<https://www.britannica.com/place/Black-Sea/Climate>Again perhaps. It also suggests small bipedal arboreal apes werejust right for the evolution of small bipedal arboreal apes.
The fact that there are no small bipedal arboreal apes in Africa indicates that there was some climate shifting.
outcompeted.
They were, by monkeys which were more ground adapted, able to swiftly run between forest stands during a drier climate phase.
The relative position of the Black Sea didn't change from then to now. >> >> The important point is its position is deep in Eurasia, wherethe southern Black Sea is between temperate and tropical.Correct. Southern Europe and the Black Sea are at the same latitudes.
This suggests they would tend to have the same climate. However, the
Black Sea is farther inland, and so suffers more continental extremes.
So any climate changes will appear first around the Black Sea and >> >> >> become more extreme compared to southern Europe.
I'm talking about from 11ma through the MSC to 5ma. The Medit. & Red Seas dried out, the Black Sea didn't.
continental climates rule.
It lies between the Atlantic-Mediterranean and the Caspian Sea, in the Peri-Tethyan basin, protected by the high Iranian plateau to the south. Not a typical continental climate.
**********************************
The climate of the landlocked Black Sea can be characterized generally
as continental (i.e., subject to pronounced seasonal temperature
variations), although climatic conditions in some parts of the basin
are controlled to a great extent by the shoreline relief. A steppe
climate, with cold winters and hot, dry summers, is found in the
northwestern part of the basin exposed to the influence of air masses
from the north.
************************************
Summer in north including Bavaria via Danube valley, winter in south including visits further southwardly.I suppose Miocene apes collected frequent-flier miles.
I acknowledge that rift was one plausible pathway from Europe toMy understanding is the Mediterranean dried out only about 6mya, long >> >> after European, and presumably Black Sea, arboreal apes went extinct. >> >No, Danuvius and later Miocene apes there were of one lineage IMO, that may have lived there until 5ma, with successive expansional waves emigrating outwardly including towards Africa.
The Red Sea is too far south to affect migration from Europe to Africa >> >> regardless of climate patterns.
It is part of the African-Anatolian rift.
Africa. The Red Sea was not, nor did it block such a pathway.
I include it provisionally, more data needed.Sounds like a segue for aquatic ape hypothesis.
Another stop.No, I am speaking of climate then *and* now. Regions around 30Moving toward 30 degrees latitude, rainfall becomes seasonally dry, >> >> >> and then almost continuously dry. My understanding is, the only
native forests south of the Caspian are in the mountains, and adjacent
to the Mediterranean coasts. Arboreal apes of any kind would find >> >> >> these deserts impassible.
You are speaking of recent climate. There are no arboreal apes there now.
degrees latitude tend to be drier than those around the equator, with >> >> exceptions due to terrain and ocean currents.
oldest known cooking (fish .78ma) and earliest waternut gathering and bread making. The region is amenable to hominins & Homo.Stop temporarily.Unclear. Do you mean stop migration temporarily? If so, keep in mind
that the same climate changes which would create arid conditions
around 30 degrees latitude would also shrink forests further north and south.
You appear to be claiming that the European Miocene apes could never have been linked to African and Asian apes. Yet they certainly were, else they wouldn't have existed at all.Such an "appearance" is incorrect. In certain cases, regions around
30 degrees latitude have/had enough rainfall to support forests. The
relevant point here is, global climate since the Miocene has gotten
colder and drier, especially around 30 degrees latitude, which has led
to the creation of large areas of treeless savannah and desert. I
don't know when European and African forests separated. Do you?
Also, the question isn't about the origin of apes generally. It's
about the origin of arboreal bipedal apes. We know they existed in
Pliocene Africa. They *may* have existed in Miocene Europe. Even if
they did, the two populations may still have evolved independently.
To a first approximation, average rainfall and temperature are
functions of latitude. However, while temperature is a function of >> >> >> the sine of latitude, rainfall is more complex. It tends to be
continuously heavy near the equator, continuously dry near 30 degrees,
and seasonally variable between 30 and 60 degrees. This general
pattern is modified, sometimes dramatically, by terrain, ocean
currents, seasons, and Milankovitch cycles.
The most significant variable is Africa's northward tectonic
migration, about a centimeter a year since before the Miocene. So, >> >> >> while central Africa has moved from south to north of the equator with
little effect, north Africa has approached and then went north of 30
degrees, making it over time ever drier, amplifying other climate >> >> >> trends, making once wooded areas into vast savannah and desert.
Yes.
Also, Africa's tectonic slide north almost certainly pinched closed >> >> >> the Gilbraltar Sttraits, which caused the Mediterranean to dry up at
least once, and likely several times as sea levels rose and fell. The
resulting hot salt basin would also have been impassible for arboreal
apes.
This is as true now as it was in theI would not claim nor disclaim that. The Levant is near the midpoint, extends the African Rift valley to Anatolia, is a major avian migration route between Africa and Eurasia, has fossil/artifacts of Homo erectus, neanderthal & sapiens
Miocene. This suggests to me there could not have been an unbroken
forested path for arboreal apes to migrate between Europe/Near East
and Central Africa.
vertebrae. This may have caused lordosis (the normal curvature of the human spine) and moved the center of mass over the hips and legs, which implies some habitual bipedal activity.https://en.wikipedia.org/wiki/Judaean_MountainsThe regions you describe above are part of the Mediterranean coastal >> >> mountains I mentioned previously.I acknowledge the facts you describe above. However, the Levant is >> >> >> savannah and desert except for a narrow strip along the Mediterranean
and up in the mountains. While this is no problem for terrestrial >> >> >> bipeds like Homo, ISTM arboreal hominids like D.guggenmosi would have
a much harder time living/migrating there.
"is".
Again, refer to microclimate of Levant 11ma - 5ma. Today's Dead Sea was once the vast brackish Lake Lisan that reached to Lebanon, a gallery forest may have reached from Anatolia to Egypt.
The Dead Sea is by no means a coastal mountain region.
These are part of a series of ranges all along the eastern
Mediterranean coast.
... which runs parallel to the Mediterranean coast.I agree a coastal Mediterranean
forest is plausible.
I'm referring to the tectonic rift valley between Zimbabwe/Zambia and Lebanon/Anatolia.
Of course, there were coastal forests as well, but they were affected by the MSC.Cite the data you think is sufficient to answer this question.
However, my understanding is the evidence is
insufficient to say if it would have been as extensive and continuous >> >> as you suggest during the time you suggest.
Haven't got enough hard data yet.
What is ISTM?
It's shorthand acronym for "It Seems To Me"
Ok, thanks.
Danuvius, Rudapithecus, Graecopithecus, Oranopithecus each had a unique trait shared with hominins. I think of them as a superspecies with local variations.-
If you place Danuvius half-way between fast brachiating bipedal long backed long achilles tendon hylobatids and bipedal Homo with long back and long achilles tendon, it fits perfectly.
Wiki:
Danuvius is thought to have had a broad chest. It is the first recorded Miocene great ape to have had the diaphragm located in the lower chest cavity, as in Homo, indicating an extended lower back and a greater number of functional lumbar
ankle loading, and the ankle would have had a hinge-like function, being most stable if positioned perpendicularly to the leg as opposed to at an angle in apes. Danuvius was likely able to achieve a strong grip with its big toes, unlike modern African
The robust finger and hypertrophied wrist and elbow bones indicate a strong grip and load bearing adaptations for the arms. The legs also show adaptations for load-bearing, especially at the hypertrophied knee joint. There was likely limited
On Sat, 19 Nov 2022 06:06:22 -0800 (PST), Daud DedenTopic: 'Human bipedalism'
<daud....@gmail.com> wrote:
On Saturday, November 19, 2022 at 6:40:01 AM UTC-5, 69jp...@gmail.com wrote:
On Fri, 18 Nov 2022 03:45:32 -0800 (PST), Daud Deden
<daud....@gmail.com> wrote:
On Friday, November 18, 2022 at 2:12:32 AM UTC-5, 69jp...@gmail.com wrote:The positions of the muzzle and/or nose relative to the foramen magnum
On Thu, 17 Nov 2022 15:53:51 -0800 (PST), Daud Deden
<daud....@gmail.com> wrote:
On Thursday, November 17, 2022 at 12:57:57 PM UTC-5, 69jp...@gmail.com wrote:My understanding is the relative position of foramen magnum doesn't
On Wed, 16 Nov 2022 22:42:03 -0800 (PST), Daud DedenIndividually.
<daud....@gmail.com> wrote:
On Thursday, November 17, 2022 at 1:29:04 AM UTC-5, Daud Deden wrote:Not sure what you mean by "mature"; the individual or the species? >> >> >
On Wednesday, November 16, 2022 at 11:08:11 AM UTC-5, 69jp...@gmail.com wrote:
On Fri, 04 Nov 2022 02:21:55 -0400, jillery <69jp...@gmail.com>
wrote:
On Thu, 3 Nov 2022 20:32:40 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Thursday, November 3, 2022 at 6:29:01 PM UTC-4, 69jp...@gmail.com wrote:
On Thu, 3 Nov 2022 07:56:05 -0700 (PDT), Daud DedenYes, I claim it is *descended from* European Miocene apes of the Black Sea region.
<daud....@gmail.com> wrote:
On Tuesday, November 1, 2022 at 4:17:31 AM UTC-4, 69jp...@gmail.com wrote:Sahelanthropus tchadensis is neither Miocene nor European, but is a
On Mon, 31 Oct 2022 15:15:01 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Monday, October 24, 2022 at 2:50:22 AM UTC-4, 69jp...@gmail.com wrote:Thank you for citing the above video. It's prelude to the ones I
Gutsick Gibbon is the Youtube handle of a biological anthropology PhD-
student named Eriks. Two of her recent videos discuss some of the
latest developments relating to the origins of human bipedalism:
<https://www.youtube.com/watch?v=kbQAgPSHbZE>
The above is a link to a 32-minute video where Erika discusses several
papers relating to Sahelanthropus tchadensis. This fossil is
remarkable in part because it's dated to about 7mya and was found in
central-african Chad, and also because it may be the oldest bipedal
hominin fossil found to date. However, there appears to be strong
disagreement whether the evidence supports bipedalism.
<https://www.youtube.com/watch?v=Nwkfkp360ps>
The above is a link to a 22-minute video where Erika discusses several
hypotheses about *why* our ancestors shifted to obligate bipedalism.
She discusses several hypotheses, and presents compelling arguments
for her preferred one.
Video by Erika on Lucy bipedalism: https://youtu.be/jo2ZLnucuHY
cited, and refers to them, and so complete a logical trilogy.
In another video, she says that Sahelanthropus was the LCA of Homo / Pan, (though probably just in the general sense). https://www.youtube.com/watch?v=g4FTbZLkpzU&t=7s
In my view, Sahelanthropus is just a southwestern European Miocene ape *Descendant*, very similar to their eastern and northern kin. I see nothing palmigrade in any Miocene ape.
Pliocene central African species.
My impression is there isn't enough evidence to show whether Pliocene
African apes descended from Miocene European apes or Miocene African
apes. Either way, there was enough time between the two eras to have
evolved differences between either Miocene populations and Pliocene S.
tchadensis.
I have recently become aware of:
<https://en.wikipedia.org/wiki/Danuvius_guggenmosi>
which was a Miocene European ape that may have evolved arboreal
bipedalism similar to S.tchadensis.
Depending on how widespread its range, and how successful its >> >> >> >> > descendants, it's plausible they lived south of the Black Sea during
the late Miocene.
The question then becomes whether it's more likely these apes found
their way into Africa to become the ancestors of Pliocene
S.tchadensis, or whether S.tchadensis evolved from Miocene African
apes.
Unfortunately, the habitat of these apes made their fossil
preservation extremely rare, and so the evidence to well support
either hypothesis is lacking.
However, the question at least conditionally can be answered by
comparing the likelihood of a migratory pathway during that time,
versus the likelihood of arboreal bipedalism evolving independently in
two populations.
There are a number of anatomic features associated with arboreal
bipedalism, some of which are necessary, ex. anterior foramen magnum,
The foramen magnum is always situated relatively more anteriorly in immature than in mature apes.[ - and men. ]
change significantly during human development.
Right. In chimps the muzzle gradually moves anteriorly relative to the foramen magnum, in Homo only the nose does.
Sorry, I erred above, I'd meant "...than in mature apes." The "and men" was NOT meant, I thought I'd erased it! Oops.
don't inform bipedalism.
It does, in tail-less upright orthogonal striding terrestrial former/partial arboreal bipeds, it does not in hopping bipeds.The topic isn't general bipedalism, but hominoid bipedalism.
Cf short-faced giant kangaroo (short tail, striding upright bipedal)
Non-hominoid species don't inform this discussion.I meant summer north of Black Sea...winter south of Black Sea
Your cited video shows an exceptional case among humans, which have relatively short arms and long legs, anatomically maladapted forHow is that an exceptional case among hominins? Only Usain Bolt can outrun qpal chimp at top speed.Imagine how much faster that person would be if he ran normally, likeAll Homo species are great apes by definition, including H.sapiens.Either way, the important point is the position and angle of foramen
magnum are diagnostic among all vertebrates for how they habitually >> >> >> hold their head, and so includes/excludes bipedalism among hominids.
Yes, but no. Great apes are bipedal except when (hurrying) on open ground they adopt quadrupedalism. Homo retains the primitive bipedal gait of hominoid ancestors, as do hylobatids.
Yes, I meant 'arboreal great apes'. Humans are terrestrial great apes, hylobatids are arboreal lesser apes.
They do/did quadrupedalism only in exceptional cases.
https://youtu.be/pCrH6BOwxe4 15mph qpal running as a patas monkey, not a chimp.
this:
<https://www.youtube.com/watch?v=k3PZgbQ8auE>
quadrupedal locomotion. Also, even though his head is in extreme
elevation, he can barely see where he's going, as his foramen magnum
is anatomically maladapted for quadrupedal motion. Silly Guinness
records notwithstanding, any human moving quadrupedally from a
predator would soon become predator poop.
That's not my understanding. My understanding is chimpanzees,Perhaps. My understanding is bipedal arboreal apes continued to walk >> >> bipedally on the ground, while non-bipedal arboreal apes also adopted >> >> quadrupedal habits on the ground.... and wet aka tropical,and some of which are incidental, ex. molar patterns. DescendantCentral Africa is and was hot,
populations are more likely to share these features than are >> >> >> >> > independent populations. This suggests to me that a sufficiently
robust fossil record could answer this question with some degree of
certainty.
Alternately, my understanding is southern Europe and central Africa
are ecological opposites, in the sense that when one is hot and dry
the other is temperate and wet.
The adoption of qpal knucklewalking by African apes indicates that their ancient habitat went through a dry phase (rainforest became patchy) forcing a terrestrial dog-like gait.
Bipedal walking is primitive in arboreal hominoids, quadrupedal walking is derived. I don't know of any 'non-bipedal arboreal apes', only monkeys.
gorillas, and orangutans are non-bipedal arboreal apes, meaning when
they are in the trees, they do not walk upright.
Their body orientation on and under branches is primarily upright, not pronograde with all limbs in compression aka quadrupedal. The modern AMHs orthogonal posture is derived, not the same as primitive upright bipedal arboreal hominoids.You continue to use above a non-standard meaning of bipedalism.
Hanging from branches using combinations of limbs isn't bipedalism any
more than is climbing up coconut palms.
As were most
arboreal apes prior to Australopithecines.
<https://www.britannica.com/place/Black-Sea/Climate>Again perhaps. It also suggests small bipedal arboreal apes werejust right for the evolution of small bipedal arboreal apes.
The fact that there are no small bipedal arboreal apes in Africa indicates that there was some climate shifting.
outcompeted.
They were, by monkeys which were more ground adapted, able to swiftly run between forest stands during a drier climate phase.
The relative position of the Black Sea didn't change from then to now. >> >> The important point is its position is deep in Eurasia, wherethe southern Black Sea is between temperate and tropical.Correct. Southern Europe and the Black Sea are at the same latitudes.
This suggests they would tend to have the same climate. However, the
Black Sea is farther inland, and so suffers more continental extremes.
So any climate changes will appear first around the Black Sea and >> >> >> become more extreme compared to southern Europe.
I'm talking about from 11ma through the MSC to 5ma. The Medit. & Red Seas dried out, the Black Sea didn't.
continental climates rule.
It lies between the Atlantic-Mediterranean and the Caspian Sea, in the Peri-Tethyan basin, protected by the high Iranian plateau to the south. Not a typical continental climate.
**********************************
The climate of the landlocked Black Sea can be characterized generally
as continental (i.e., subject to pronounced seasonal temperature
variations), although climatic conditions in some parts of the basin
are controlled to a great extent by the shoreline relief. A steppe
climate, with cold winters and hot, dry summers, is found in the
northwestern part of the basin exposed to the influence of air masses
from the north.
************************************
Summer in north including Bavaria via Danube valley, winter in south including visits further southwardly.
I suppose Miocene apes collected frequent-flier miles.
I acknowledge that rift was one plausible pathway from Europe toMy understanding is the Mediterranean dried out only about 6mya, long >> >> after European, and presumably Black Sea, arboreal apes went extinct. >> >No, Danuvius and later Miocene apes there were of one lineage IMO, that may have lived there until 5ma, with successive expansional waves emigrating outwardly including towards Africa.
The Red Sea is too far south to affect migration from Europe to Africa >> >> regardless of climate patterns.
It is part of the African-Anatolian rift.
Africa. The Red Sea was not, nor did it block such a pathway.
I include it provisionally, more data needed.Sounds like a segue for aquatic ape hypothesis.
No, I am speaking of climate then *and* now. Regions around 30Moving toward 30 degrees latitude, rainfall becomes seasonally dry, >> >> >> and then almost continuously dry. My understanding is, the only
native forests south of the Caspian are in the mountains, and adjacent
to the Mediterranean coasts. Arboreal apes of any kind would find >> >> >> these deserts impassible.
You are speaking of recent climate. There are no arboreal apes there now.
degrees latitude tend to be drier than those around the equator, with >> >> exceptions due to terrain and ocean currents.
Stop temporarily.Unclear. Do you mean stop migration temporarily? If so, keep in mind
that the same climate changes which would create arid conditions
around 30 degrees latitude would also shrink forests further north and south.
You appear to be claiming that the European Miocene apes could never have been linked to African and Asian apes. Yet they certainly were, else they wouldn't have existed at all.Such an "appearance" is incorrect. In certain cases, regions around
30 degrees latitude have/had enough rainfall to support forests. The
relevant point here is, global climate since the Miocene has gotten
colder and drier, especially around 30 degrees latitude, which has led
to the creation of large areas of treeless savannah and desert. I
don't know when European and African forests separated. Do you?
oldest known cooking (fish .78ma) and earliest waternut gathering and bread making. The region is amenable to hominins & Homo.Also, the question isn't about the origin of apes generally. It's
about the origin of arboreal bipedal apes. We know they existed in
Pliocene Africa. They *may* have existed in Miocene Europe. Even if
they did, the two populations may still have evolved independently.
To a first approximation, average rainfall and temperature are
functions of latitude. However, while temperature is a function of >> >> >> the sine of latitude, rainfall is more complex. It tends to be
continuously heavy near the equator, continuously dry near 30 degrees,
and seasonally variable between 30 and 60 degrees. This general
pattern is modified, sometimes dramatically, by terrain, ocean
currents, seasons, and Milankovitch cycles.
The most significant variable is Africa's northward tectonic
migration, about a centimeter a year since before the Miocene. So, >> >> >> while central Africa has moved from south to north of the equator with
little effect, north Africa has approached and then went north of 30
degrees, making it over time ever drier, amplifying other climate >> >> >> trends, making once wooded areas into vast savannah and desert.
Yes.
Also, Africa's tectonic slide north almost certainly pinched closed >> >> >> the Gilbraltar Sttraits, which caused the Mediterranean to dry up at
least once, and likely several times as sea levels rose and fell. The
resulting hot salt basin would also have been impassible for arboreal
apes.
This is as true now as it was in theI would not claim nor disclaim that. The Levant is near the midpoint, extends the African Rift valley to Anatolia, is a major avian migration route between Africa and Eurasia, has fossil/artifacts of Homo erectus, neanderthal & sapiens
Miocene. This suggests to me there could not have been an unbroken
forested path for arboreal apes to migrate between Europe/Near East
and Central Africa.
vertebrae. This may have caused lordosis (the normal curvature of the human spine) and moved the center of mass over the hips and legs, which implies some habitual bipedal activity.https://en.wikipedia.org/wiki/Judaean_MountainsThe regions you describe above are part of the Mediterranean coastal >> >> mountains I mentioned previously.I acknowledge the facts you describe above. However, the Levant is >> >> >> savannah and desert except for a narrow strip along the Mediterranean
and up in the mountains. While this is no problem for terrestrial >> >> >> bipeds like Homo, ISTM arboreal hominids like D.guggenmosi would have
a much harder time living/migrating there.
"is".
Again, refer to microclimate of Levant 11ma - 5ma. Today's Dead Sea was once the vast brackish Lake Lisan that reached to Lebanon, a gallery forest may have reached from Anatolia to Egypt.
The Dead Sea is by no means a coastal mountain region.
These are part of a series of ranges all along the eastern
Mediterranean coast.
... which runs parallel to the Mediterranean coast.I agree a coastal Mediterranean
forest is plausible.
I'm referring to the tectonic rift valley between Zimbabwe/Zambia and Lebanon/Anatolia.
Of course, there were coastal forests as well, but they were affected by the MSC.Cite the data you think is sufficient to answer this question.
However, my understanding is the evidence is
insufficient to say if it would have been as extensive and continuous >> >> as you suggest during the time you suggest.
Haven't got enough hard data yet.
What is ISTM?
It's shorthand acronym for "It Seems To Me"
Ok, thanks.
Danuvius, Rudapithecus, Graecopithecus, Oranopithecus each had a unique trait shared with hominins. I think of them as a superspecies with local variations.-
If you place Danuvius half-way between fast brachiating bipedal long backed long achilles tendon hylobatids and bipedal Homo with long back and long achilles tendon, it fits perfectly.
Wiki:
Danuvius is thought to have had a broad chest. It is the first recorded Miocene great ape to have had the diaphragm located in the lower chest cavity, as in Homo, indicating an extended lower back and a greater number of functional lumbar
ankle loading, and the ankle would have had a hinge-like function, being most stable if positioned perpendicularly to the leg as opposed to at an angle in apes. Danuvius was likely able to achieve a strong grip with its big toes, unlike modern African
The robust finger and hypertrophied wrist and elbow bones indicate a strong grip and load bearing adaptations for the arms. The legs also show adaptations for load-bearing, especially at the hypertrophied knee joint. There was likely limited
On Saturday, November 19, 2022 at 2:20:20 PM UTC-5, 69jp...@gmail.com wrote: >> On Sat, 19 Nov 2022 06:06:22 -0800 (PST), Daud Deden
<daud....@gmail.com> wrote:
On Saturday, November 19, 2022 at 6:40:01 AM UTC-5, 69jp...@gmail.com wrote:The topic isn't general bipedalism, but hominoid bipedalism.
On Fri, 18 Nov 2022 03:45:32 -0800 (PST), Daud Deden
<daud....@gmail.com> wrote:
On Friday, November 18, 2022 at 2:12:32 AM UTC-5, 69jp...@gmail.com wrote:The positions of the muzzle and/or nose relative to the foramen magnum >> >> don't inform bipedalism.
On Thu, 17 Nov 2022 15:53:51 -0800 (PST), Daud Deden
<daud....@gmail.com> wrote:
On Thursday, November 17, 2022 at 12:57:57 PM UTC-5, 69jp...@gmail.com wrote:My understanding is the relative position of foramen magnum doesn't >> >> >> change significantly during human development.
On Wed, 16 Nov 2022 22:42:03 -0800 (PST), Daud DedenIndividually.
<daud....@gmail.com> wrote:
On Thursday, November 17, 2022 at 1:29:04 AM UTC-5, Daud Deden wrote:Not sure what you mean by "mature"; the individual or the species? >> >> >> >
On Wednesday, November 16, 2022 at 11:08:11 AM UTC-5, 69jp...@gmail.com wrote:
On Fri, 04 Nov 2022 02:21:55 -0400, jillery <69jp...@gmail.com>
wrote:
On Thu, 3 Nov 2022 20:32:40 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Thursday, November 3, 2022 at 6:29:01 PM UTC-4, 69jp...@gmail.com wrote:
On Thu, 3 Nov 2022 07:56:05 -0700 (PDT), Daud DedenYes, I claim it is *descended from* European Miocene apes of the Black Sea region.
<daud....@gmail.com> wrote:
On Tuesday, November 1, 2022 at 4:17:31 AM UTC-4, 69jp...@gmail.com wrote:Sahelanthropus tchadensis is neither Miocene nor European, but is a
On Mon, 31 Oct 2022 15:15:01 -0700 (PDT), Daud Deden >> >> >> >> >> > >>> >> <daud....@gmail.com> wrote:
On Monday, October 24, 2022 at 2:50:22 AM UTC-4, 69jp...@gmail.com wrote:Thank you for citing the above video. It's prelude to the ones I
Gutsick Gibbon is the Youtube handle of a biological anthropology PhD-
student named Eriks. Two of her recent videos discuss some of the
latest developments relating to the origins of human bipedalism:
<https://www.youtube.com/watch?v=kbQAgPSHbZE>
The above is a link to a 32-minute video where Erika discusses several
papers relating to Sahelanthropus tchadensis. This fossil is
remarkable in part because it's dated to about 7mya and was found in
central-african Chad, and also because it may be the oldest bipedal
hominin fossil found to date. However, there appears to be strong
disagreement whether the evidence supports bipedalism.
<https://www.youtube.com/watch?v=Nwkfkp360ps>
The above is a link to a 22-minute video where Erika discusses several
hypotheses about *why* our ancestors shifted to obligate bipedalism.
She discusses several hypotheses, and presents compelling arguments
for her preferred one.
Video by Erika on Lucy bipedalism: https://youtu.be/jo2ZLnucuHY
cited, and refers to them, and so complete a logical trilogy.
In another video, she says that Sahelanthropus was the LCA of Homo / Pan, (though probably just in the general sense). https://www.youtube.com/watch?v=g4FTbZLkpzU&t=7s
In my view, Sahelanthropus is just a southwestern European Miocene ape *Descendant*, very similar to their eastern and northern kin. I see nothing palmigrade in any Miocene ape.
Pliocene central African species.
My impression is there isn't enough evidence to show whether Pliocene
African apes descended from Miocene European apes or Miocene African
apes. Either way, there was enough time between the two eras to have
evolved differences between either Miocene populations and Pliocene S.
tchadensis.
I have recently become aware of:
<https://en.wikipedia.org/wiki/Danuvius_guggenmosi>
which was a Miocene European ape that may have evolved arboreal
bipedalism similar to S.tchadensis.
Depending on how widespread its range, and how successful its >> >> >> >> >> > descendants, it's plausible they lived south of the Black Sea during
the late Miocene.
The question then becomes whether it's more likely these apes found
their way into Africa to become the ancestors of Pliocene
S.tchadensis, or whether S.tchadensis evolved from Miocene African
apes.
Unfortunately, the habitat of these apes made their fossil
preservation extremely rare, and so the evidence to well support
either hypothesis is lacking.
However, the question at least conditionally can be answered by
comparing the likelihood of a migratory pathway during that time,
versus the likelihood of arboreal bipedalism evolving independently in
two populations.
There are a number of anatomic features associated with arboreal
bipedalism, some of which are necessary, ex. anterior foramen magnum,
The foramen magnum is always situated relatively more anteriorly in immature than in mature apes.[ - and men. ]
Right. In chimps the muzzle gradually moves anteriorly relative to the foramen magnum, in Homo only the nose does.
Sorry, I erred above, I'd meant "...than in mature apes." The "and men" was NOT meant, I thought I'd erased it! Oops.
It does, in tail-less upright orthogonal striding terrestrial former/partial arboreal bipeds, it does not in hopping bipeds.
Cf short-faced giant kangaroo (short tail, striding upright bipedal)
Non-hominoid species don't inform this discussion.
Topic: 'Human bipedalism'
A version of hominoid bipedalism eg. Homo, hylobatid
A version of primate bipedalism eg. Sifaka
A version of mammal bipedalism eg. Kangaroo
A version of animal bipedalism eg. Hoatzin (adult)
foot posture were proposed as anatomical correlates with speed. In addition to skeletal proportions, soft tissue and whole body proportions are important components of the locomotor system. To further distinguish patas anatomy from other Old WorldYour cited video shows an exceptional case among humans, which haveHow is that an exceptional case among hominins? Only Usain Bolt can outrun qpal chimp at top speed.Imagine how much faster that person would be if he ran normally, likeYes, I meant 'arboreal great apes'. Humans are terrestrial great apes, hylobatids are arboreal lesser apes.All Homo species are great apes by definition, including H.sapiens. >> >> >Either way, the important point is the position and angle of foramen
magnum are diagnostic among all vertebrates for how they habitually
hold their head, and so includes/excludes bipedalism among hominids.
Yes, but no. Great apes are bipedal except when (hurrying) on open ground they adopt quadrupedalism. Homo retains the primitive bipedal gait of hominoid ancestors, as do hylobatids.
They do/did quadrupedalism only in exceptional cases.
https://youtu.be/pCrH6BOwxe4 15mph qpal running as a patas monkey, not a chimp.
this:
<https://www.youtube.com/watch?v=k3PZgbQ8auE>
relatively short arms and long legs, anatomically maladapted for
quadrupedal locomotion.
Humans are faster qpal palm-down sprinter and qpal endurance runner than any other hominoid.
Patas monkey's arms are shorter than their legs: https://www.britannica.com/animal/patas-monkey
Locomotor Anatomy and Behavior of Patas Monkeys (Erythrocebus patas) with Comparison to Vervet Monkeys (Cercopithecus aethiops)
Adrienne L. Zihlman and Carol E. Underwood
Additional article information
Abstract
Patas monkeys (Erythrocebus patas) living in African savanna woodlands and grassland habitats have a locomotor system that allows them to run fast, presumably to avoid predators. Long fore- and hindlimbs, long foot bones, short toes, and a digitigrade
vervets give them access to highly dispersed, nutritious foods, water, and sleeping trees. Furthermore, patas monkeys have physiological adaptations that enable them to tolerate and dissipate heat. These features all contribute to the distinctadaptation that is the patas monkeys' basis for survival in grassland and savanna woodland areas.
climb trees, qpal running is just the short sprint to flight.Also, even though his head is in extreme
elevation, he can barely see where he's going, as his foramen magnum
is anatomically maladapted for quadrupedal motion. Silly Guinness
records notwithstanding, any human moving quadrupedally from a
predator would soon become predator poop.
Why? Carrying a blade pirate-style teeth-clenched, with a few pards similarly equipped, would present predators with a serious challenge. Bipedally, better weapons could be carried, of course, but running itself isn't enough. Patas, verbet & baboons
You continue to use above a non-standard meaning of bipedalism.That's not my understanding. My understanding is chimpanzees,Perhaps. My understanding is bipedal arboreal apes continued to walk >> >> >> bipedally on the ground, while non-bipedal arboreal apes also adopted >> >> >> quadrupedal habits on the ground.... and wet aka tropical,and some of which are incidental, ex. molar patterns. DescendantCentral Africa is and was hot,
populations are more likely to share these features than are >> >> >> >> >> > independent populations. This suggests to me that a sufficiently
robust fossil record could answer this question with some degree of
certainty.
Alternately, my understanding is southern Europe and central Africa
are ecological opposites, in the sense that when one is hot and dry
the other is temperate and wet.
The adoption of qpal knucklewalking by African apes indicates that their ancient habitat went through a dry phase (rainforest became patchy) forcing a terrestrial dog-like gait.
Bipedal walking is primitive in arboreal hominoids, quadrupedal walking is derived. I don't know of any 'non-bipedal arboreal apes', only monkeys.
gorillas, and orangutans are non-bipedal arboreal apes, meaning when
they are in the trees, they do not walk upright.
Their body orientation on and under branches is primarily upright, not pronograde with all limbs in compression aka quadrupedal. The modern AMHs orthogonal posture is derived, not the same as primitive upright bipedal arboreal hominoids.
Please direct me to "a standard meaning of bipedalism". Afaik, bipedalism is a trait of locomoting on 2 legs in compression, whether the hands are swinging, carrying or plucking.
Sloths are quadrumanual, orangs are also called that when hanging tensionally from four limbs, but bipedal when walking on thick branches.
Hanging from branches using combinations of limbs isn't bipedalism any
more than is climbing up coconut palms.
Suspension itself is not bipedalism.
They weren't sessile, but very mobile.I suppose Miocene apes collected frequent-flier miles.As were most
arboreal apes prior to Australopithecines.
<https://www.britannica.com/place/Black-Sea/Climate>Again perhaps. It also suggests small bipedal arboreal apes werejust right for the evolution of small bipedal arboreal apes.
The fact that there are no small bipedal arboreal apes in Africa indicates that there was some climate shifting.
outcompeted.
They were, by monkeys which were more ground adapted, able to swiftly run between forest stands during a drier climate phase.
The relative position of the Black Sea didn't change from then to now.the southern Black Sea is between temperate and tropical.Correct. Southern Europe and the Black Sea are at the same latitudes.
This suggests they would tend to have the same climate. However, the
Black Sea is farther inland, and so suffers more continental extremes.
So any climate changes will appear first around the Black Sea and >> >> >> >> become more extreme compared to southern Europe.
I'm talking about from 11ma through the MSC to 5ma. The Medit. & Red Seas dried out, the Black Sea didn't.
The important point is its position is deep in Eurasia, where
continental climates rule.
It lies between the Atlantic-Mediterranean and the Caspian Sea, in the Peri-Tethyan basin, protected by the high Iranian plateau to the south. Not a typical continental climate.
**********************************
The climate of the landlocked Black Sea can be characterized generally >> >> as continental (i.e., subject to pronounced seasonal temperature
variations), although climatic conditions in some parts of the basin
are controlled to a great extent by the shoreline relief. A steppe
climate, with cold winters and hot, dry summers, is found in the
northwestern part of the basin exposed to the influence of air masses
from the north.
************************************
Summer in north including Bavaria via Danube valley, winter in south including visits further southwardly.
Sounds like a segue for aquatic ape hypothesis.I acknowledge that rift was one plausible pathway from Europe toMy understanding is the Mediterranean dried out only about 6mya, long >> >> >> after European, and presumably Black Sea, arboreal apes went extinct. >> >> >No, Danuvius and later Miocene apes there were of one lineage IMO, that may have lived there until 5ma, with successive expansional waves emigrating outwardly including towards Africa.
The Red Sea is too far south to affect migration from Europe to Africa
regardless of climate patterns.
It is part of the African-Anatolian rift.
Africa. The Red Sea was not, nor did it block such a pathway.
I include it provisionally, more data needed.
Most proponents of that hypothesis tend to refuse to acknowledge that all extant (and by extension, archaic) Homo sleep well sheltered (dry, warm, shielded) from the elements (or try to be). Thus it is unrealistic imo.
Of course, I refer to the surrounding region, which today is hyper-arid
Another stop.No, I am speaking of climate then *and* now. Regions around 30Moving toward 30 degrees latitude, rainfall becomes seasonally dry,
and then almost continuously dry. My understanding is, the only
native forests south of the Caspian are in the mountains, and adjacent
to the Mediterranean coasts. Arboreal apes of any kind would find >> >> >> >> these deserts impassible.
You are speaking of recent climate. There are no arboreal apes there now.
degrees latitude tend to be drier than those around the equator, with >> >> >> exceptions due to terrain and ocean currents.
Stop temporarily.
oldest known cooking (fish .78ma) and earliest waternut gathering and bread making. The region is amenable to hominins & Homo.Unclear. Do you mean stop migration temporarily? If so, keep in mind
that the same climate changes which would create arid conditions
around 30 degrees latitude would also shrink forests further north and
south.
You appear to be claiming that the European Miocene apes could never have been linked to African and Asian apes. Yet they certainly were, else they wouldn't have existed at all.Such an "appearance" is incorrect. In certain cases, regions around
30 degrees latitude have/had enough rainfall to support forests. The
relevant point here is, global climate since the Miocene has gotten
colder and drier, especially around 30 degrees latitude, which has led >> >> to the creation of large areas of treeless savannah and desert. I
don't know when European and African forests separated. Do you?
Also, the question isn't about the origin of apes generally. It's
about the origin of arboreal bipedal apes. We know they existed in
Pliocene Africa. They *may* have existed in Miocene Europe. Even if
they did, the two populations may still have evolved independently.
To a first approximation, average rainfall and temperature are
functions of latitude. However, while temperature is a function of >> >> >> >> the sine of latitude, rainfall is more complex. It tends to be
continuously heavy near the equator, continuously dry near 30 degrees,
and seasonally variable between 30 and 60 degrees. This general
pattern is modified, sometimes dramatically, by terrain, ocean
currents, seasons, and Milankovitch cycles.
The most significant variable is Africa's northward tectonic
migration, about a centimeter a year since before the Miocene. So, >> >> >> >> while central Africa has moved from south to north of the equator with
little effect, north Africa has approached and then went north of 30
degrees, making it over time ever drier, amplifying other climate >> >> >> >> trends, making once wooded areas into vast savannah and desert.
Yes.
Also, Africa's tectonic slide north almost certainly pinched closed
the Gilbraltar Sttraits, which caused the Mediterranean to dry up at
least once, and likely several times as sea levels rose and fell. The
resulting hot salt basin would also have been impassible for arboreal
apes.
This is as true now as it was in theI would not claim nor disclaim that. The Levant is near the midpoint, extends the African Rift valley to Anatolia, is a major avian migration route between Africa and Eurasia, has fossil/artifacts of Homo erectus, neanderthal & sapiens
Miocene. This suggests to me there could not have been an unbroken
forested path for arboreal apes to migrate between Europe/Near East
and Central Africa.
vertebrae. This may have caused lordosis (the normal curvature of the human spine) and moved the center of mass over the hips and legs, which implies some habitual bipedal activity.https://en.wikipedia.org/wiki/Judaean_MountainsThe regions you describe above are part of the Mediterranean coastal >> >> >> mountains I mentioned previously.I acknowledge the facts you describe above. However, the Levant is >> >> >> >> savannah and desert except for a narrow strip along the Mediterranean
and up in the mountains. While this is no problem for terrestrial >> >> >> >> bipeds like Homo, ISTM arboreal hominids like D.guggenmosi would have
a much harder time living/migrating there.
"is".
Again, refer to microclimate of Levant 11ma - 5ma. Today's Dead Sea was once the vast brackish Lake Lisan that reached to Lebanon, a gallery forest may have reached from Anatolia to Egypt.
The Dead Sea is by no means a coastal mountain region.
These are part of a series of ranges all along the eastern
Mediterranean coast.
... which runs parallel to the Mediterranean coast.I agree a coastal Mediterranean
forest is plausible.
I'm referring to the tectonic rift valley between Zimbabwe/Zambia and Lebanon/Anatolia.
Of course, there were coastal forests as well, but they were affected by the MSC.Cite the data you think is sufficient to answer this question.
However, my understanding is the evidence is
insufficient to say if it would have been as extensive and continuous >> >> >> as you suggest during the time you suggest.
Haven't got enough hard data yet.
What is ISTM?
It's shorthand acronym for "It Seems To Me"
Ok, thanks.
Danuvius, Rudapithecus, Graecopithecus, Oranopithecus each had a unique trait shared with hominins. I think of them as a superspecies with local variations.-
If you place Danuvius half-way between fast brachiating bipedal long backed long achilles tendon hylobatids and bipedal Homo with long back and long achilles tendon, it fits perfectly.
Wiki:
Danuvius is thought to have had a broad chest. It is the first recorded Miocene great ape to have had the diaphragm located in the lower chest cavity, as in Homo, indicating an extended lower back and a greater number of functional lumbar
ankle loading, and the ankle would have had a hinge-like function, being most stable if positioned perpendicularly to the leg as opposed to at an angle in apes. Danuvius was likely able to achieve a strong grip with its big toes, unlike modern African
The robust finger and hypertrophied wrist and elbow bones indicate a strong grip and load bearing adaptations for the arms. The legs also show adaptations for load-bearing, especially at the hypertrophied knee joint. There was likely limited
On Sat, 19 Nov 2022 12:43:27 -0800 (PST), Daud Deden
<daud....@gmail.com> wrote:
On Saturday, November 19, 2022 at 2:20:20 PM UTC-5, 69jp...@gmail.com wrote:<inserted your reply in your later post>
On Sat, 19 Nov 2022 06:06:22 -0800 (PST), Daud Deden
<daud....@gmail.com> wrote:
On Saturday, November 19, 2022 at 6:40:01 AM UTC-5, 69jp...@gmail.com wrote:The topic isn't general bipedalism, but hominoid bipedalism.
On Fri, 18 Nov 2022 03:45:32 -0800 (PST), Daud Deden
<daud....@gmail.com> wrote:
On Friday, November 18, 2022 at 2:12:32 AM UTC-5, 69jp...@gmail.com wrote:The positions of the muzzle and/or nose relative to the foramen magnum >> >> don't inform bipedalism.
On Thu, 17 Nov 2022 15:53:51 -0800 (PST), Daud Deden
<daud....@gmail.com> wrote:
On Thursday, November 17, 2022 at 12:57:57 PM UTC-5, 69jp...@gmail.com wrote:My understanding is the relative position of foramen magnum doesn't >> >> >> change significantly during human development.
On Wed, 16 Nov 2022 22:42:03 -0800 (PST), Daud Deden
<daud....@gmail.com> wrote:
On Thursday, November 17, 2022 at 1:29:04 AM UTC-5, Daud Deden wrote:Not sure what you mean by "mature"; the individual or the species?
On Wednesday, November 16, 2022 at 11:08:11 AM UTC-5, 69jp...@gmail.com wrote:
On Fri, 04 Nov 2022 02:21:55 -0400, jillery <69jp...@gmail.com>
wrote:
On Thu, 3 Nov 2022 20:32:40 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Thursday, November 3, 2022 at 6:29:01 PM UTC-4, 69jp...@gmail.com wrote:
On Thu, 3 Nov 2022 07:56:05 -0700 (PDT), Daud DedenYes, I claim it is *descended from* European Miocene apes of the Black Sea region.
<daud....@gmail.com> wrote:
On Tuesday, November 1, 2022 at 4:17:31 AM UTC-4, 69jp...@gmail.com wrote:Sahelanthropus tchadensis is neither Miocene nor European, but is a
On Mon, 31 Oct 2022 15:15:01 -0700 (PDT), Daud Deden >> >> >> >> >> > >>> >> <daud....@gmail.com> wrote:
On Monday, October 24, 2022 at 2:50:22 AM UTC-4, 69jp...@gmail.com wrote:Thank you for citing the above video. It's prelude to the ones I
Gutsick Gibbon is the Youtube handle of a biological anthropology PhD-
student named Eriks. Two of her recent videos discuss some of the
latest developments relating to the origins of human bipedalism:
<https://www.youtube.com/watch?v=kbQAgPSHbZE>
The above is a link to a 32-minute video where Erika discusses several
papers relating to Sahelanthropus tchadensis. This fossil is
remarkable in part because it's dated to about 7mya and was found in
central-african Chad, and also because it may be the oldest bipedal
hominin fossil found to date. However, there appears to be strong
disagreement whether the evidence supports bipedalism.
<https://www.youtube.com/watch?v=Nwkfkp360ps>
The above is a link to a 22-minute video where Erika discusses several
hypotheses about *why* our ancestors shifted to obligate bipedalism.
She discusses several hypotheses, and presents compelling arguments
for her preferred one.
Video by Erika on Lucy bipedalism: https://youtu.be/jo2ZLnucuHY
cited, and refers to them, and so complete a logical trilogy.
In another video, she says that Sahelanthropus was the LCA of Homo / Pan, (though probably just in the general sense). https://www.youtube.com/watch?v=g4FTbZLkpzU&t=7s
In my view, Sahelanthropus is just a southwestern European Miocene ape *Descendant*, very similar to their eastern and northern kin. I see nothing palmigrade in any Miocene ape.
Pliocene central African species.
My impression is there isn't enough evidence to show whether Pliocene
African apes descended from Miocene European apes or Miocene African
apes. Either way, there was enough time between the two eras to have
evolved differences between either Miocene populations and Pliocene S.
tchadensis.
I have recently become aware of:
<https://en.wikipedia.org/wiki/Danuvius_guggenmosi>
which was a Miocene European ape that may have evolved arboreal
bipedalism similar to S.tchadensis.
Depending on how widespread its range, and how successful its
descendants, it's plausible they lived south of the Black Sea during
the late Miocene.
The question then becomes whether it's more likely these apes found
their way into Africa to become the ancestors of Pliocene >> >> >> >> >> > S.tchadensis, or whether S.tchadensis evolved from Miocene African
apes.
Unfortunately, the habitat of these apes made their fossil >> >> >> >> >> > preservation extremely rare, and so the evidence to well support
either hypothesis is lacking.
However, the question at least conditionally can be answered by
comparing the likelihood of a migratory pathway during that time,
versus the likelihood of arboreal bipedalism evolving independently in
two populations.
There are a number of anatomic features associated with arboreal
bipedalism, some of which are necessary, ex. anterior foramen magnum,
The foramen magnum is always situated relatively more anteriorly in immature than in mature apes.[ - and men. ]
Individually.
Right. In chimps the muzzle gradually moves anteriorly relative to the foramen magnum, in Homo only the nose does.
Sorry, I erred above, I'd meant "...than in mature apes." The "and men" was NOT meant, I thought I'd erased it! Oops.
It does, in tail-less upright orthogonal striding terrestrial former/partial arboreal bipeds, it does not in hopping bipeds.
Cf short-faced giant kangaroo (short tail, striding upright bipedal)
Non-hominoid species don't inform this discussion.
Topic: 'Human bipedalism'
Fair point. To be precise, the topic is the *origin* of human
bipedalism. But human bipedalism didn't originate in humans, but is
derived from *hominoid* ancestors like australopiths or earlier.
A version of hominoid bipedalism eg. Homo, hylobatidA version of animal bipedalism eg. T.rex
A version of primate bipedalism eg. Sifaka
A version of mammal bipedalism eg. Kangaroo
A version of animal bipedalism eg. Hoatzin (adult)
If you want to expand the discussion beyond the origins of human
bipedalism, then don't limit yourself to bipedalism; include all
animal locomotion, up to and including invertebrates. Good luck with
that.
If you want to make coherent and relevant points about the origin of
human bipedalism, then constrain your comments to Homo species and
their likely ancestors.
foot posture were proposed as anatomical correlates with speed. In addition to skeletal proportions, soft tissue and whole body proportions are important components of the locomotor system. To further distinguish patas anatomy from other Old WorldYour cited video shows an exceptional case among humans, which haveHow is that an exceptional case among hominins? Only Usain Bolt can outrun qpal chimp at top speed.Imagine how much faster that person would be if he ran normally, like >> >> this:Yes, I meant 'arboreal great apes'. Humans are terrestrial great apes, hylobatids are arboreal lesser apes.All Homo species are great apes by definition, including H.sapiens. >> >> >Either way, the important point is the position and angle of foramen
magnum are diagnostic among all vertebrates for how they habitually
hold their head, and so includes/excludes bipedalism among hominids.
Yes, but no. Great apes are bipedal except when (hurrying) on open ground they adopt quadrupedalism. Homo retains the primitive bipedal gait of hominoid ancestors, as do hylobatids.
They do/did quadrupedalism only in exceptional cases.
https://youtu.be/pCrH6BOwxe4 15mph qpal running as a patas monkey, not a chimp.
<https://www.youtube.com/watch?v=k3PZgbQ8auE>
relatively short arms and long legs, anatomically maladapted for
quadrupedal locomotion.
Humans are faster qpal palm-down sprinter and qpal endurance runner than any other hominoid.
Patas monkey's arms are shorter than their legs: https://www.britannica.com/animal/patas-monkey
Locomotor Anatomy and Behavior of Patas Monkeys (Erythrocebus patas) with Comparison to Vervet Monkeys (Cercopithecus aethiops)
Adrienne L. Zihlman and Carol E. Underwood
Additional article information
Abstract
Patas monkeys (Erythrocebus patas) living in African savanna woodlands and grassland habitats have a locomotor system that allows them to run fast, presumably to avoid predators. Long fore- and hindlimbs, long foot bones, short toes, and a digitigrade
adaptation that is the patas monkeys' basis for survival in grassland and savanna woodland areas.vervets give them access to highly dispersed, nutritious foods, water, and sleeping trees. Furthermore, patas monkeys have physiological adaptations that enable them to tolerate and dissipate heat. These features all contribute to the distinct
Footraces between humans and patas monkeys are exceptional events.climb trees, qpal running is just the short sprint to flight.
Also, even though his head is in extreme
elevation, he can barely see where he's going, as his foramen magnum
is anatomically maladapted for quadrupedal motion. Silly Guinness
records notwithstanding, any human moving quadrupedally from a
predator would soon become predator poop.
Why? Carrying a blade pirate-style teeth-clenched, with a few pards similarly equipped, would present predators with a serious challenge. Bipedally, better weapons could be carried, of course, but running itself isn't enough. Patas, vervet & baboons
Imagine yourself running quadrupedally with a blade pirate-style teeth clenched. Now imagine yourself running out of breath and exhausted as
the predator you're running from catches up and eats you.
Fun is fun, but at least make your jokes relevant to the topic.
You continue to use above a non-standard meaning of bipedalism.That's not my understanding. My understanding is chimpanzees,Perhaps. My understanding is bipedal arboreal apes continued to walk... and wet aka tropical,and some of which are incidental, ex. molar patterns. DescendantCentral Africa is and was hot,
populations are more likely to share these features than are
independent populations. This suggests to me that a sufficiently
robust fossil record could answer this question with some degree of
certainty.
Alternately, my understanding is southern Europe and central Africa
are ecological opposites, in the sense that when one is hot and dry
the other is temperate and wet.
The adoption of qpal knucklewalking by African apes indicates that their ancient habitat went through a dry phase (rainforest became patchy) forcing a terrestrial dog-like gait.
bipedally on the ground, while non-bipedal arboreal apes also adopted
quadrupedal habits on the ground.
Bipedal walking is primitive in arboreal hominoids, quadrupedal walking is derived. I don't know of any 'non-bipedal arboreal apes', only monkeys.
gorillas, and orangutans are non-bipedal arboreal apes, meaning when >> >> they are in the trees, they do not walk upright.
Their body orientation on and under branches is primarily upright, not pronograde with all limbs in compression aka quadrupedal. The modern AMHs orthogonal posture is derived, not the same as primitive upright bipedal arboreal hominoids.
Please direct me to "a standard meaning of bipedalism". Afaik, bipedalism is a trait of locomoting on 2 legs in compression, whether the hands are swinging, carrying or plucking.I acknowledge I am no authority to assert a standard meaning of
Sloths are quadrumanual, orangs are also called that when hanging tensionally from four limbs, but bipedal when walking on thick branches.
*human* bipedalism. But I rely on the list of diagnostic features as described by Erika's aka Gutsick Gibbon's, who is at least one
authority. From the video you cited previously:
<https://youtu.be/jo2ZLnucuHY>
1. Foramen magnum and occipital condyles positioned anterior and
angled vertically.
2. Vertebrate lumbar lordosis.
3. Bowl-shaped pelvis with sagittally oriented iliia and anterior
iliac spine.
4. Broad sacrum.
5. Thick cortical bone around femur neck.
6. Flattened elliptical distal condyles.
7. Opterator externus groove.
8. Valgus knee.
9. Three arches of foot's sole.
Also, I note that Erika expressed the same criticism I did about your quadrupedal human, that the foramen magnum precludes such habitual
behavior.
Hanging from branches using combinations of limbs isn't bipedalism any
more than is climbing up coconut palms.
Suspension itself is not bipedalism.That's what I said.
I am unaware of any arboreal species which seasonally migrate.They weren't sessile, but very mobile.I suppose Miocene apes collected frequent-flier miles.As were most
arboreal apes prior to Australopithecines.
<https://www.britannica.com/place/Black-Sea/Climate>Again perhaps. It also suggests small bipedal arboreal apes werejust right for the evolution of small bipedal arboreal apes.
The fact that there are no small bipedal arboreal apes in Africa indicates that there was some climate shifting.
outcompeted.
They were, by monkeys which were more ground adapted, able to swiftly run between forest stands during a drier climate phase.
The relative position of the Black Sea didn't change from then to now.the southern Black Sea is between temperate and tropical.Correct. Southern Europe and the Black Sea are at the same latitudes.
This suggests they would tend to have the same climate. However, the
Black Sea is farther inland, and so suffers more continental extremes.
So any climate changes will appear first around the Black Sea and
become more extreme compared to southern Europe.
I'm talking about from 11ma through the MSC to 5ma. The Medit. & Red Seas dried out, the Black Sea didn't.
The important point is its position is deep in Eurasia, where
continental climates rule.
It lies between the Atlantic-Mediterranean and the Caspian Sea, in the Peri-Tethyan basin, protected by the high Iranian plateau to the south. Not a typical continental climate.
**********************************
The climate of the landlocked Black Sea can be characterized generally >> >> as continental (i.e., subject to pronounced seasonal temperature
variations), although climatic conditions in some parts of the basin >> >> are controlled to a great extent by the shoreline relief. A steppe
climate, with cold winters and hot, dry summers, is found in the
northwestern part of the basin exposed to the influence of air masses >> >> from the north.
************************************
Summer in north including Bavaria via Danube valley, winter in south including visits further southwardly.
best of my knowledge, although they may have a large home range, they
stick to one area throughout the year. This would suggest migrating
Miocene arboreal apes are a unique exception. Do you know of any
extant arboreal animals which seasonally migrate?
Sounds like a segue for aquatic ape hypothesis.I acknowledge that rift was one plausible pathway from Europe toMy understanding is the Mediterranean dried out only about 6mya, long
after European, and presumably Black Sea, arboreal apes went extinct.
No, Danuvius and later Miocene apes there were of one lineage IMO, that may have lived there until 5ma, with successive expansional waves emigrating outwardly including towards Africa.
The Red Sea is too far south to affect migration from Europe to Africa
regardless of climate patterns.
It is part of the African-Anatolian rift.
Africa. The Red Sea was not, nor did it block such a pathway.
I include it provisionally, more data needed.
Most proponents of that hypothesis tend to refuse to acknowledge that all extant (and by extension, archaic) Homo sleep well sheltered (dry, warm, shielded) from the elements (or try to be). Thus it is unrealistic imo.
Of course, I refer to the surrounding region, which today is hyper-arid
To inform that I was stopping until i could get wifi again.Ok, stop as in "be right back". But this isn't a real-time chat.Another stop.No, I am speaking of climate then *and* now. Regions around 30Moving toward 30 degrees latitude, rainfall becomes seasonally dry,
and then almost continuously dry. My understanding is, the only >> >> >> >> native forests south of the Caspian are in the mountains, and adjacent
to the Mediterranean coasts. Arboreal apes of any kind would find
these deserts impassible.
You are speaking of recent climate. There are no arboreal apes there now.
degrees latitude tend to be drier than those around the equator, with
exceptions due to terrain and ocean currents.
Stop temporarily.
What's the point of mentioning it?
oldest known cooking (fish .78ma) and earliest waternut gathering and bread making. The region is amenable to hominins & Homo.Unclear. Do you mean stop migration temporarily? If so, keep in mind
that the same climate changes which would create arid conditions
around 30 degrees latitude would also shrink forests further north and
south.
You appear to be claiming that the European Miocene apes could never have been linked to African and Asian apes. Yet they certainly were, else they wouldn't have existed at all.Such an "appearance" is incorrect. In certain cases, regions around
30 degrees latitude have/had enough rainfall to support forests. The >> >> relevant point here is, global climate since the Miocene has gotten
colder and drier, especially around 30 degrees latitude, which has led >> >> to the creation of large areas of treeless savannah and desert. I
don't know when European and African forests separated. Do you?
Also, the question isn't about the origin of apes generally. It's
about the origin of arboreal bipedal apes. We know they existed in
Pliocene Africa. They *may* have existed in Miocene Europe. Even if
they did, the two populations may still have evolved independently.
To a first approximation, average rainfall and temperature are >> >> >> >> functions of latitude. However, while temperature is a function ofYes.
the sine of latitude, rainfall is more complex. It tends to be >> >> >> >> continuously heavy near the equator, continuously dry near 30 degrees,
and seasonally variable between 30 and 60 degrees. This general >> >> >> >> pattern is modified, sometimes dramatically, by terrain, ocean >> >> >> >> currents, seasons, and Milankovitch cycles.
The most significant variable is Africa's northward tectonic
migration, about a centimeter a year since before the Miocene. So,
while central Africa has moved from south to north of the equator with
little effect, north Africa has approached and then went north of 30
degrees, making it over time ever drier, amplifying other climate
trends, making once wooded areas into vast savannah and desert. >> >> >> >
Also, Africa's tectonic slide north almost certainly pinched closed
the Gilbraltar Sttraits, which caused the Mediterranean to dry up at
least once, and likely several times as sea levels rose and fell. The
resulting hot salt basin would also have been impassible for arboreal
apes.
This is as true now as it was in theI would not claim nor disclaim that. The Levant is near the midpoint, extends the African Rift valley to Anatolia, is a major avian migration route between Africa and Eurasia, has fossil/artifacts of Homo erectus, neanderthal & sapiens
Miocene. This suggests to me there could not have been an unbroken
forested path for arboreal apes to migrate between Europe/Near East
and Central Africa.
vertebrae. This may have caused lordosis (the normal curvature of the human spine) and moved the center of mass over the hips and legs, which implies some habitual bipedal activity.https://en.wikipedia.org/wiki/Judaean_MountainsThe regions you describe above are part of the Mediterranean coastalI acknowledge the facts you describe above. However, the Levant is
savannah and desert except for a narrow strip along the Mediterranean
and up in the mountains. While this is no problem for terrestrial
bipeds like Homo, ISTM arboreal hominids like D.guggenmosi would have
a much harder time living/migrating there.
"is".
Again, refer to microclimate of Levant 11ma - 5ma. Today's Dead Sea was once the vast brackish Lake Lisan that reached to Lebanon, a gallery forest may have reached from Anatolia to Egypt.
mountains I mentioned previously.
The Dead Sea is by no means a coastal mountain region.
These are part of a series of ranges all along the eastern
Mediterranean coast.
... which runs parallel to the Mediterranean coast.I agree a coastal Mediterranean
forest is plausible.
I'm referring to the tectonic rift valley between Zimbabwe/Zambia and Lebanon/Anatolia.
Of course, there were coastal forests as well, but they were affected by the MSC.Cite the data you think is sufficient to answer this question.
However, my understanding is the evidence is
insufficient to say if it would have been as extensive and continuous
as you suggest during the time you suggest.
Haven't got enough hard data yet.
What is ISTM?
It's shorthand acronym for "It Seems To Me"
Ok, thanks.
Danuvius, Rudapithecus, Graecopithecus, Oranopithecus each had a unique trait shared with hominins. I think of them as a superspecies with local variations.-
If you place Danuvius half-way between fast brachiating bipedal long backed long achilles tendon hylobatids and bipedal Homo with long back and long achilles tendon, it fits perfectly.
Wiki:
Danuvius is thought to have had a broad chest. It is the first recorded Miocene great ape to have had the diaphragm located in the lower chest cavity, as in Homo, indicating an extended lower back and a greater number of functional lumbar
limited ankle loading, and the ankle would have had a hinge-like function, being most stable if positioned perpendicularly to the leg as opposed to at an angle in apes. Danuvius was likely able to achieve a strong grip with its big toes, unlike modern
The robust finger and hypertrophied wrist and elbow bones indicate a strong grip and load bearing adaptations for the arms. The legs also show adaptations for load-bearing, especially at the hypertrophied knee joint. There was likely
On Sunday, November 20, 2022 at 2:01:18 AM UTC-5, 69jp...@gmail.com wrote:
On Sat, 19 Nov 2022 12:43:27 -0800 (PST), Daud Deden
<daud....@gmail.com> wrote:
On Saturday, November 19, 2022 at 2:20:20 PM UTC-5, 69jp...@gmail.com wrote:<inserted your reply in your later post>
On Sat, 19 Nov 2022 06:06:22 -0800 (PST), Daud Deden
<daud....@gmail.com> wrote:
On Saturday, November 19, 2022 at 6:40:01 AM UTC-5, 69jp...@gmail.com wrote:Non-hominoid species don't inform this discussion.
On Fri, 18 Nov 2022 03:45:32 -0800 (PST), Daud Deden
<daud....@gmail.com> wrote:
On Friday, November 18, 2022 at 2:12:32 AM UTC-5, 69jp...@gmail.com wrote:The positions of the muzzle and/or nose relative to the foramen magnum
On Thu, 17 Nov 2022 15:53:51 -0800 (PST), Daud Deden
<daud....@gmail.com> wrote:
On Thursday, November 17, 2022 at 12:57:57 PM UTC-5, 69jp...@gmail.com wrote:My understanding is the relative position of foramen magnum doesn't
On Wed, 16 Nov 2022 22:42:03 -0800 (PST), Daud Deden
<daud....@gmail.com> wrote:
On Thursday, November 17, 2022 at 1:29:04 AM UTC-5, Daud Deden wrote:Not sure what you mean by "mature"; the individual or the species?
On Wednesday, November 16, 2022 at 11:08:11 AM UTC-5, 69jp...@gmail.com wrote:
On Fri, 04 Nov 2022 02:21:55 -0400, jillery <69jp...@gmail.com>
wrote:
On Thu, 3 Nov 2022 20:32:40 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Thursday, November 3, 2022 at 6:29:01 PM UTC-4, 69jp...@gmail.com wrote:
On Thu, 3 Nov 2022 07:56:05 -0700 (PDT), Daud Deden >> >> >> >> >> > >>> <daud....@gmail.com> wrote:Yes, I claim it is *descended from* European Miocene apes of the Black Sea region.
On Tuesday, November 1, 2022 at 4:17:31 AM UTC-4, 69jp...@gmail.com wrote:Sahelanthropus tchadensis is neither Miocene nor European, but is a
On Mon, 31 Oct 2022 15:15:01 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Monday, October 24, 2022 at 2:50:22 AM UTC-4, 69jp...@gmail.com wrote:Thank you for citing the above video. It's prelude to the ones I
Gutsick Gibbon is the Youtube handle of a biological anthropology PhD-
student named Eriks. Two of her recent videos discuss some of the
latest developments relating to the origins of human bipedalism:
<https://www.youtube.com/watch?v=kbQAgPSHbZE> >> >> >> >> >> > >>> >> >>
The above is a link to a 32-minute video where Erika discusses several
papers relating to Sahelanthropus tchadensis. This fossil is
remarkable in part because it's dated to about 7mya and was found in
central-african Chad, and also because it may be the oldest bipedal
hominin fossil found to date. However, there appears to be strong
disagreement whether the evidence supports bipedalism.
<https://www.youtube.com/watch?v=Nwkfkp360ps> >> >> >> >> >> > >>> >> >>
The above is a link to a 22-minute video where Erika discusses several
hypotheses about *why* our ancestors shifted to obligate bipedalism.
She discusses several hypotheses, and presents compelling arguments
for her preferred one.
Video by Erika on Lucy bipedalism: https://youtu.be/jo2ZLnucuHY
cited, and refers to them, and so complete a logical trilogy.
In another video, she says that Sahelanthropus was the LCA of Homo / Pan, (though probably just in the general sense). https://www.youtube.com/watch?v=g4FTbZLkpzU&t=7s
In my view, Sahelanthropus is just a southwestern European Miocene ape *Descendant*, very similar to their eastern and northern kin. I see nothing palmigrade in any Miocene ape.
Pliocene central African species.
My impression is there isn't enough evidence to show whether Pliocene
African apes descended from Miocene European apes or Miocene African
apes. Either way, there was enough time between the two eras to have
evolved differences between either Miocene populations and Pliocene S.
tchadensis.
I have recently become aware of:
<https://en.wikipedia.org/wiki/Danuvius_guggenmosi>
which was a Miocene European ape that may have evolved arboreal
bipedalism similar to S.tchadensis.
Depending on how widespread its range, and how successful its
descendants, it's plausible they lived south of the Black Sea during
the late Miocene.
The question then becomes whether it's more likely these apes found
their way into Africa to become the ancestors of Pliocene >> >> >> >> >> > S.tchadensis, or whether S.tchadensis evolved from Miocene African
apes.
Unfortunately, the habitat of these apes made their fossil
preservation extremely rare, and so the evidence to well support
either hypothesis is lacking.
However, the question at least conditionally can be answered by
comparing the likelihood of a migratory pathway during that time,
versus the likelihood of arboreal bipedalism evolving independently in
two populations.
There are a number of anatomic features associated with arboreal
bipedalism, some of which are necessary, ex. anterior foramen magnum,
The foramen magnum is always situated relatively more anteriorly in immature than in mature apes.[ - and men. ]
Individually.
change significantly during human development.
Right. In chimps the muzzle gradually moves anteriorly relative to the foramen magnum, in Homo only the nose does.
Sorry, I erred above, I'd meant "...than in mature apes." The "and men" was NOT meant, I thought I'd erased it! Oops.
don't inform bipedalism.
It does, in tail-less upright orthogonal striding terrestrial former/partial arboreal bipeds, it does not in hopping bipeds.
Cf short-faced giant kangaroo (short tail, striding upright bipedal) >> The topic isn't general bipedalism, but hominoid bipedalism.
Topic: 'Human bipedalism'
digitigrade foot posture were proposed as anatomical correlates with speed. In addition to skeletal proportions, soft tissue and whole body proportions are important components of the locomotor system. To further distinguish patas anatomy from other OldFair point. To be precise, the topic is the *origin* of human
bipedalism. But human bipedalism didn't originate in humans, but is derived from *hominoid* ancestors like australopiths or earlier.
A version of hominoid bipedalism eg. Homo, hylobatidA version of animal bipedalism eg. T.rex
A version of primate bipedalism eg. Sifaka
A version of mammal bipedalism eg. Kangaroo
A version of animal bipedalism eg. Hoatzin (adult)
If you want to expand the discussion beyond the origins of human bipedalism, then don't limit yourself to bipedalism; include allThat is a good way to lose useful information relative to the topic, IMO. You've just erased hylobatids from the conversation. Just like Lieberman did in his endurance running H. erectus fantasy.
animal locomotion, up to and including invertebrates. Good luck with
that.
If you want to make coherent and relevant points about the origin of
human bipedalism, then constrain your comments to Homo species and
their likely ancestors.
Adult chimps have protruding muzzles and are mostly qpal on the ground. Adult humans have flat faces and are bipedal on the ground.
Your cited video shows an exceptional case among humans, which haveHow is that an exceptional case among hominins? Only Usain Bolt can outrun qpal chimp at top speed.Imagine how much faster that person would be if he ran normally, likeAll Homo species are great apes by definition, including H.sapiens.Either way, the important point is the position and angle of foramen
magnum are diagnostic among all vertebrates for how they habitually
hold their head, and so includes/excludes bipedalism among hominids.
Yes, but no. Great apes are bipedal except when (hurrying) on open ground they adopt quadrupedalism. Homo retains the primitive bipedal gait of hominoid ancestors, as do hylobatids.
Yes, I meant 'arboreal great apes'. Humans are terrestrial great apes, hylobatids are arboreal lesser apes.
They do/did quadrupedalism only in exceptional cases.
https://youtu.be/pCrH6BOwxe4 15mph qpal running as a patas monkey, not a chimp.
this:
<https://www.youtube.com/watch?v=k3PZgbQ8auE>
relatively short arms and long legs, anatomically maladapted for
quadrupedal locomotion.
Humans are faster qpal palm-down sprinter and qpal endurance runner than any other hominoid.
Patas monkey's arms are shorter than their legs: https://www.britannica.com/animal/patas-monkey
Locomotor Anatomy and Behavior of Patas Monkeys (Erythrocebus patas) with Comparison to Vervet Monkeys (Cercopithecus aethiops)
Adrienne L. Zihlman and Carol E. Underwood
Additional article information
Abstract
Patas monkeys (Erythrocebus patas) living in African savanna woodlands and grassland habitats have a locomotor system that allows them to run fast, presumably to avoid predators. Long fore- and hindlimbs, long foot bones, short toes, and a
adaptation that is the patas monkeys' basis for survival in grassland and savanna woodland areas.vervets give them access to highly dispersed, nutritious foods, water, and sleeping trees. Furthermore, patas monkeys have physiological adaptations that enable them to tolerate and dissipate heat. These features all contribute to the distinct
climb trees, qpal running is just the short sprint to flight.Footraces between humans and patas monkeys are exceptional events.
Also, even though his head is in extreme
elevation, he can barely see where he's going, as his foramen magnum
is anatomically maladapted for quadrupedal motion. Silly Guinness
records notwithstanding, any human moving quadrupedally from a
predator would soon become predator poop.
Why? Carrying a blade pirate-style teeth-clenched, with a few pards similarly equipped, would present predators with a serious challenge. Bipedally, better weapons could be carried, of course, but running itself isn't enough. Patas, vervet & baboons
Predators attack from behind. There is no behind in a circle. But there is a vulnerable behind in an encircled predator. That is why the first knife slashes a rear hamstring/achilles/artery, while a pard is taunting up front, keeping the predator'sImagine yourself running quadrupedally with a blade pirate-style teeth clenched. Now imagine yourself running out of breath and exhausted asDon't bring a fang to a knife fight. Don't run with scissors. But most importantly, don't get encircled, because then you're prey. My pards and I run out only far enough to encircle said predator, then sing kumbaya as we slash it into ribbons of jerky.
the predator you're running from catches up and eats you.
Fun is fun, but at least make your jokes relevant to the topic.
You continue to use above a non-standard meaning of bipedalism.That's not my understanding. My understanding is chimpanzees,Perhaps. My understanding is bipedal arboreal apes continued to walk... and wet aka tropical,and some of which are incidental, ex. molar patterns. DescendantCentral Africa is and was hot,
populations are more likely to share these features than are
independent populations. This suggests to me that a sufficiently
robust fossil record could answer this question with some degree of
certainty.
Alternately, my understanding is southern Europe and central Africa
are ecological opposites, in the sense that when one is hot and dry
the other is temperate and wet.
The adoption of qpal knucklewalking by African apes indicates that their ancient habitat went through a dry phase (rainforest became patchy) forcing a terrestrial dog-like gait.
bipedally on the ground, while non-bipedal arboreal apes also adopted
quadrupedal habits on the ground.
Bipedal walking is primitive in arboreal hominoids, quadrupedal walking is derived. I don't know of any 'non-bipedal arboreal apes', only monkeys.
gorillas, and orangutans are non-bipedal arboreal apes, meaning when >> >> they are in the trees, they do not walk upright.
Their body orientation on and under branches is primarily upright, not pronograde with all limbs in compression aka quadrupedal. The modern AMHs orthogonal posture is derived, not the same as primitive upright bipedal arboreal hominoids.
Please direct me to "a standard meaning of bipedalism". Afaik, bipedalism is a trait of locomoting on 2 legs in compression, whether the hands are swinging, carrying or plucking.I acknowledge I am no authority to assert a standard meaning of
Sloths are quadrumanual, orangs are also called that when hanging tensionally from four limbs, but bipedal when walking on thick branches.
*human* bipedalism. But I rely on the list of diagnostic features as described by Erika's aka Gutsick Gibbon's, who is at least one
authority. From the video you cited previously:
<https://youtu.be/jo2ZLnucuHY>
1. Foramen magnum and occipital condyles positioned anterior and
angled vertically.
2. Vertebrate lumbar lordosis.
3. Bowl-shaped pelvis with sagittally oriented iliia and anterior
iliac spine.
4. Broad sacrum.
5. Thick cortical bone around femur neck.
6. Flattened elliptical distal condyles.
7. Opterator externus groove.
8. Valgus knee.
9. Three arches of foot's sole.
Also, I note that Erika expressed the same criticism I did about your quadrupedal human, that the foramen magnum precludes such habitual behavior.Rather obvious that. Yet we can do it, quickly when we have to. Our body form is closer to monkeys than to apes in some ways.
A list of features does not a meaning make.
Please direct me to "a standard meaning of bipedalism". You demanded it, I requested it.
Because there are some octopi that notoriously walk bipedally, they don't have any of those features.
BUT THEY DO WALK ON TWO LIMBS IN COMPRESSION. And **THAT** is the standard meaning of bipedalism.
So you must incorporate that into your description of human bipedalism. And so should Erika.
Hanging from branches using combinations of limbs isn't bipedalism any >> more than is climbing up coconut palms.
Songbirds? If you meant hominoids only, they are all tropical. Miocene apes had warm/cool seasons, they did migrate.Suspension itself is not bipedalism.That's what I said.
I am unaware of any arboreal species which seasonally migrate.They weren't sessile, but very mobile.I suppose Miocene apes collected frequent-flier miles.As were most
arboreal apes prior to Australopithecines.
<https://www.britannica.com/place/Black-Sea/Climate>Again perhaps. It also suggests small bipedal arboreal apes were >> >> >> outcompeted.just right for the evolution of small bipedal arboreal apes.
The fact that there are no small bipedal arboreal apes in Africa indicates that there was some climate shifting.
They were, by monkeys which were more ground adapted, able to swiftly run between forest stands during a drier climate phase.
The relative position of the Black Sea didn't change from then to now.the southern Black Sea is between temperate and tropical.Correct. Southern Europe and the Black Sea are at the same latitudes.
This suggests they would tend to have the same climate. However, the
Black Sea is farther inland, and so suffers more continental extremes.
So any climate changes will appear first around the Black Sea and
become more extreme compared to southern Europe.
I'm talking about from 11ma through the MSC to 5ma. The Medit. & Red Seas dried out, the Black Sea didn't.
The important point is its position is deep in Eurasia, where
continental climates rule.
It lies between the Atlantic-Mediterranean and the Caspian Sea, in the Peri-Tethyan basin, protected by the high Iranian plateau to the south. Not a typical continental climate.
**********************************
The climate of the landlocked Black Sea can be characterized generally
as continental (i.e., subject to pronounced seasonal temperature
variations), although climatic conditions in some parts of the basin >> >> are controlled to a great extent by the shoreline relief. A steppe >> >> climate, with cold winters and hot, dry summers, is found in the
northwestern part of the basin exposed to the influence of air masses
from the north.
************************************
Summer in north including Bavaria via Danube valley, winter in south including visits further southwardly.
To the
best of my knowledge, although they may have a large home range, they stick to one area throughout the year. This would suggest migrating Miocene arboreal apes are a unique exception. Do you know of anySongbirds? Which 'arboreal animals' do you mean, hominoids only?
extant arboreal animals which seasonally migrate?
Sounds like a segue for aquatic ape hypothesis.I acknowledge that rift was one plausible pathway from Europe toMy understanding is the Mediterranean dried out only about 6mya, long
after European, and presumably Black Sea, arboreal apes went extinct.
No, Danuvius and later Miocene apes there were of one lineage IMO, that may have lived there until 5ma, with successive expansional waves emigrating outwardly including towards Africa.
The Red Sea is too far south to affect migration from Europe to Africa
regardless of climate patterns.
It is part of the African-Anatolian rift.
Africa. The Red Sea was not, nor did it block such a pathway.
I include it provisionally, more data needed.
Most proponents of that hypothesis tend to refuse to acknowledge that all extant (and by extension, archaic) Homo sleep well sheltered (dry, warm, shielded) from the elements (or try to be). Thus it is unrealistic imo.
Of course, I refer to the surrounding region, which today is hyper-arid
oldest known cooking (fish .78ma) and earliest waternut gathering and bread making. The region is amenable to hominins & Homo.To inform that I was stopping until i could get wifi again.Ok, stop as in "be right back". But this isn't a real-time chat.Another stop.No, I am speaking of climate then *and* now. Regions around 30Moving toward 30 degrees latitude, rainfall becomes seasonally dry,
and then almost continuously dry. My understanding is, the only
native forests south of the Caspian are in the mountains, and adjacent
to the Mediterranean coasts. Arboreal apes of any kind would find
these deserts impassible.
You are speaking of recent climate. There are no arboreal apes there now.
degrees latitude tend to be drier than those around the equator, with
exceptions due to terrain and ocean currents.
Stop temporarily.
What's the point of mentioning it?
Unclear. Do you mean stop migration temporarily? If so, keep in mind
that the same climate changes which would create arid conditions
around 30 degrees latitude would also shrink forests further north and >> south.
You appear to be claiming that the European Miocene apes could never have been linked to African and Asian apes. Yet they certainly were, else they wouldn't have existed at all.Such an "appearance" is incorrect. In certain cases, regions around >> >> 30 degrees latitude have/had enough rainfall to support forests. The >> >> relevant point here is, global climate since the Miocene has gotten >> >> colder and drier, especially around 30 degrees latitude, which has led
to the creation of large areas of treeless savannah and desert. I
don't know when European and African forests separated. Do you?
Also, the question isn't about the origin of apes generally. It's
about the origin of arboreal bipedal apes. We know they existed in >> >> Pliocene Africa. They *may* have existed in Miocene Europe. Even if >> >> they did, the two populations may still have evolved independently. >> >> >> >> To a first approximation, average rainfall and temperature are >> >> >> >> functions of latitude. However, while temperature is a function of
the sine of latitude, rainfall is more complex. It tends to be >> >> >> >> continuously heavy near the equator, continuously dry near 30 degrees,
and seasonally variable between 30 and 60 degrees. This general
pattern is modified, sometimes dramatically, by terrain, ocean >> >> >> >> currents, seasons, and Milankovitch cycles.
The most significant variable is Africa's northward tectonic >> >> >> >> migration, about a centimeter a year since before the Miocene. So,
while central Africa has moved from south to north of the equator with
little effect, north Africa has approached and then went north of 30
degrees, making it over time ever drier, amplifying other climate
trends, making once wooded areas into vast savannah and desert.
Yes.
Also, Africa's tectonic slide north almost certainly pinched closed
the Gilbraltar Sttraits, which caused the Mediterranean to dry up at
least once, and likely several times as sea levels rose and fell. The
resulting hot salt basin would also have been impassible for arboreal
apes.
This is as true now as it was in theI would not claim nor disclaim that. The Levant is near the midpoint, extends the African Rift valley to Anatolia, is a major avian migration route between Africa and Eurasia, has fossil/artifacts of Homo erectus, neanderthal & sapiens
Miocene. This suggests to me there could not have been an unbroken
forested path for arboreal apes to migrate between Europe/Near East
and Central Africa.
lumbar vertebrae. This may have caused lordosis (the normal curvature of the human spine) and moved the center of mass over the hips and legs, which implies some habitual bipedal activity.https://en.wikipedia.org/wiki/Judaean_MountainsThe regions you describe above are part of the Mediterranean coastalI acknowledge the facts you describe above. However, the Levant is
savannah and desert except for a narrow strip along the Mediterranean
and up in the mountains. While this is no problem for terrestrial
bipeds like Homo, ISTM arboreal hominids like D.guggenmosi would have
a much harder time living/migrating there.
"is".
Again, refer to microclimate of Levant 11ma - 5ma. Today's Dead Sea was once the vast brackish Lake Lisan that reached to Lebanon, a gallery forest may have reached from Anatolia to Egypt.
mountains I mentioned previously.
The Dead Sea is by no means a coastal mountain region.
These are part of a series of ranges all along the eastern
Mediterranean coast.
... which runs parallel to the Mediterranean coast.I agree a coastal Mediterranean
forest is plausible.
I'm referring to the tectonic rift valley between Zimbabwe/Zambia and Lebanon/Anatolia.
Of course, there were coastal forests as well, but they were affected by the MSC.Cite the data you think is sufficient to answer this question.
However, my understanding is the evidence is
insufficient to say if it would have been as extensive and continuous
as you suggest during the time you suggest.
Haven't got enough hard data yet.
What is ISTM?
It's shorthand acronym for "It Seems To Me"
Ok, thanks.
Danuvius, Rudapithecus, Graecopithecus, Oranopithecus each had a unique trait shared with hominins. I think of them as a superspecies with local variations.-
If you place Danuvius half-way between fast brachiating bipedal long backed long achilles tendon hylobatids and bipedal Homo with long back and long achilles tendon, it fits perfectly.
Wiki:
Danuvius is thought to have had a broad chest. It is the first recorded Miocene great ape to have had the diaphragm located in the lower chest cavity, as in Homo, indicating an extended lower back and a greater number of functional
limited ankle loading, and the ankle would have had a hinge-like function, being most stable if positioned perpendicularly to the leg as opposed to at an angle in apes. Danuvius was likely able to achieve a strong grip with its big toes, unlike modern
The robust finger and hypertrophied wrist and elbow bones indicate a strong grip and load bearing adaptations for the arms. The legs also show adaptations for load-bearing, especially at the hypertrophied knee joint. There was likely
On Sunday, November 20, 2022 at 2:01:18 AM UTC-5, 69jp...@gmail.com wrote:
On Sat, 19 Nov 2022 12:43:27 -0800 (PST), Daud Deden
<daud....@gmail.com> wrote:
On Saturday, November 19, 2022 at 2:20:20 PM UTC-5, 69jp...@gmail.com wrote:<inserted your reply in your later post>
On Sat, 19 Nov 2022 06:06:22 -0800 (PST), Daud Deden
<daud....@gmail.com> wrote:
On Saturday, November 19, 2022 at 6:40:01 AM UTC-5, 69jp...@gmail.com wrote:The topic isn't general bipedalism, but hominoid bipedalism.
On Fri, 18 Nov 2022 03:45:32 -0800 (PST), Daud Deden
<daud....@gmail.com> wrote:
On Friday, November 18, 2022 at 2:12:32 AM UTC-5, 69jp...@gmail.com wrote:The positions of the muzzle and/or nose relative to the foramen magnum
On Thu, 17 Nov 2022 15:53:51 -0800 (PST), Daud Deden
<daud....@gmail.com> wrote:
On Thursday, November 17, 2022 at 12:57:57 PM UTC-5, 69jp...@gmail.com wrote:My understanding is the relative position of foramen magnum doesn't
On Wed, 16 Nov 2022 22:42:03 -0800 (PST), Daud Deden
<daud....@gmail.com> wrote:
On Thursday, November 17, 2022 at 1:29:04 AM UTC-5, Daud Deden wrote:Not sure what you mean by "mature"; the individual or the species?
On Wednesday, November 16, 2022 at 11:08:11 AM UTC-5, 69jp...@gmail.com wrote:
On Fri, 04 Nov 2022 02:21:55 -0400, jillery <69jp...@gmail.com>
wrote:
On Thu, 3 Nov 2022 20:32:40 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Thursday, November 3, 2022 at 6:29:01 PM UTC-4, 69jp...@gmail.com wrote:
On Thu, 3 Nov 2022 07:56:05 -0700 (PDT), Daud DedenYes, I claim it is *descended from* European Miocene apes of the Black Sea region.
<daud....@gmail.com> wrote:
On Tuesday, November 1, 2022 at 4:17:31 AM UTC-4, 69jp...@gmail.com wrote:Sahelanthropus tchadensis is neither Miocene nor European, but is a
On Mon, 31 Oct 2022 15:15:01 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Monday, October 24, 2022 at 2:50:22 AM UTC-4, 69jp...@gmail.com wrote:Thank you for citing the above video. It's prelude to the ones I
Gutsick Gibbon is the Youtube handle of a biological anthropology PhD-
student named Eriks. Two of her recent videos discuss some of the
latest developments relating to the origins of human bipedalism:
<https://www.youtube.com/watch?v=kbQAgPSHbZE>
The above is a link to a 32-minute video where Erika discusses several
papers relating to Sahelanthropus tchadensis. This fossil is
remarkable in part because it's dated to about 7mya and was found in
central-african Chad, and also because it may be the oldest bipedal
hominin fossil found to date. However, there appears to be strong
disagreement whether the evidence supports bipedalism.
<https://www.youtube.com/watch?v=Nwkfkp360ps>
The above is a link to a 22-minute video where Erika discusses several
hypotheses about *why* our ancestors shifted to obligate bipedalism.
She discusses several hypotheses, and presents compelling arguments
for her preferred one.
Video by Erika on Lucy bipedalism: https://youtu.be/jo2ZLnucuHY
cited, and refers to them, and so complete a logical trilogy.
In another video, she says that Sahelanthropus was the LCA of Homo / Pan, (though probably just in the general sense). https://www.youtube.com/watch?v=g4FTbZLkpzU&t=7s
In my view, Sahelanthropus is just a southwestern European Miocene ape *Descendant*, very similar to their eastern and northern kin. I see nothing palmigrade in any Miocene ape.
Pliocene central African species.
My impression is there isn't enough evidence to show whether Pliocene
African apes descended from Miocene European apes or Miocene African
apes. Either way, there was enough time between the two eras to have
evolved differences between either Miocene populations and Pliocene S.
tchadensis.
I have recently become aware of:
<https://en.wikipedia.org/wiki/Danuvius_guggenmosi>
which was a Miocene European ape that may have evolved arboreal
bipedalism similar to S.tchadensis.
Depending on how widespread its range, and how successful its
descendants, it's plausible they lived south of the Black Sea during
the late Miocene.
The question then becomes whether it's more likely these apes found
their way into Africa to become the ancestors of Pliocene >> >> >> >> >> >> > S.tchadensis, or whether S.tchadensis evolved from Miocene African
apes.
Unfortunately, the habitat of these apes made their fossil >> >> >> >> >> >> > preservation extremely rare, and so the evidence to well support
either hypothesis is lacking.
However, the question at least conditionally can be answered by
comparing the likelihood of a migratory pathway during that time,
versus the likelihood of arboreal bipedalism evolving independently in
two populations.
There are a number of anatomic features associated with arboreal
bipedalism, some of which are necessary, ex. anterior foramen magnum,
The foramen magnum is always situated relatively more anteriorly in immature than in mature apes.[ - and men. ]
Individually.
change significantly during human development.
Right. In chimps the muzzle gradually moves anteriorly relative to the foramen magnum, in Homo only the nose does.
Sorry, I erred above, I'd meant "...than in mature apes." The "and men" was NOT meant, I thought I'd erased it! Oops.
don't inform bipedalism.
It does, in tail-less upright orthogonal striding terrestrial former/partial arboreal bipeds, it does not in hopping bipeds.
Cf short-faced giant kangaroo (short tail, striding upright bipedal)
Non-hominoid species don't inform this discussion.
Topic: 'Human bipedalism'
Fair point. To be precise, the topic is the *origin* of human
bipedalism. But human bipedalism didn't originate in humans, but is
derived from *hominoid* ancestors like australopiths or earlier.
A version of hominoid bipedalism eg. Homo, hylobatidA version of animal bipedalism eg. T.rex
A version of primate bipedalism eg. Sifaka
A version of mammal bipedalism eg. Kangaroo
A version of animal bipedalism eg. Hoatzin (adult)
If you want to expand the discussion beyond the origins of human
bipedalism, then don't limit yourself to bipedalism; include all
animal locomotion, up to and including invertebrates. Good luck with
that.
If you want to make coherent and relevant points about the origin of
human bipedalism, then constrain your comments to Homo species and
their likely ancestors.
That is a good way to lose useful information relative to the topic, IMO. You've just erased hylobatids from the conversation. Just like Lieberman did in his endurance running H. erectus fantasy.
Adult chimps have protruding muzzles and are mostly qpal on the ground.digitigrade foot posture were proposed as anatomical correlates with speed. In addition to skeletal proportions, soft tissue and whole body proportions are important components of the locomotor system. To further distinguish patas anatomy from other Old
Adult humans have flat faces and are bipedal on the ground.
Your cited video shows an exceptional case among humans, which haveHow is that an exceptional case among hominins? Only Usain Bolt can outrun qpal chimp at top speed.Imagine how much faster that person would be if he ran normally, like >> >> >> this:All Homo species are great apes by definition, including H.sapiens.Either way, the important point is the position and angle of foramen
magnum are diagnostic among all vertebrates for how they habitually
hold their head, and so includes/excludes bipedalism among hominids.
Yes, but no. Great apes are bipedal except when (hurrying) on open ground they adopt quadrupedalism. Homo retains the primitive bipedal gait of hominoid ancestors, as do hylobatids.
Yes, I meant 'arboreal great apes'. Humans are terrestrial great apes, hylobatids are arboreal lesser apes.
They do/did quadrupedalism only in exceptional cases.
https://youtu.be/pCrH6BOwxe4 15mph qpal running as a patas monkey, not a chimp.
<https://www.youtube.com/watch?v=k3PZgbQ8auE>
relatively short arms and long legs, anatomically maladapted for
quadrupedal locomotion.
Humans are faster qpal palm-down sprinter and qpal endurance runner than any other hominoid.
Patas monkey's arms are shorter than their legs: https://www.britannica.com/animal/patas-monkey
Locomotor Anatomy and Behavior of Patas Monkeys (Erythrocebus patas) with Comparison to Vervet Monkeys (Cercopithecus aethiops)
Adrienne L. Zihlman and Carol E. Underwood
Additional article information
Abstract
Patas monkeys (Erythrocebus patas) living in African savanna woodlands and grassland habitats have a locomotor system that allows them to run fast, presumably to avoid predators. Long fore- and hindlimbs, long foot bones, short toes, and a
ofadaptation that is the patas monkeys' basis for survival in grassland and savanna woodland areas.
vervets give them access to highly dispersed, nutritious foods, water, and sleeping trees. Furthermore, patas monkeys have physiological adaptations that enable them to tolerate and dissipate heat. These features all contribute to the distinct
climb trees, qpal running is just the short sprint to flight.Footraces between humans and patas monkeys are exceptional events.
Also, even though his head is in extreme
elevation, he can barely see where he's going, as his foramen magnum
is anatomically maladapted for quadrupedal motion. Silly Guinness
records notwithstanding, any human moving quadrupedally from a
predator would soon become predator poop.
Why? Carrying a blade pirate-style teeth-clenched, with a few pards similarly equipped, would present predators with a serious challenge. Bipedally, better weapons could be carried, of course, but running itself isn't enough. Patas, vervet & baboons
Predators attack from behind. There is no behind in a circle. But there is a vulnerable behind in an encircled predator. That is why the first knife slashes a rear hamstring/achilles/artery, while a pard is taunting up front, keeping the predator'sImagine yourself running quadrupedally with a blade pirate-style teeth
clenched. Now imagine yourself running out of breath and exhausted as
the predator you're running from catches up and eats you.
Don't bring a fang to a knife fight. Don't run with scissors. But most importantly, don't get encircled, because then you're prey. My pards and I run out only far enough to encircle said predator, then sing kumbaya as we slash it into ribbons of jerky.
oldest known cooking (fish .78ma) and earliest waternut gathering and bread making. The region is amenable to hominins & Homo.Fun is fun, but at least make your jokes relevant to the topic.
I acknowledge I am no authority to assert a standard meaning ofYou continue to use above a non-standard meaning of bipedalism.That's not my understanding. My understanding is chimpanzees,Perhaps. My understanding is bipedal arboreal apes continued to walk... and wet aka tropical,and some of which are incidental, ex. molar patterns. DescendantCentral Africa is and was hot,
populations are more likely to share these features than are
independent populations. This suggests to me that a sufficiently
robust fossil record could answer this question with some degree of
certainty.
Alternately, my understanding is southern Europe and central Africa
are ecological opposites, in the sense that when one is hot and dry
the other is temperate and wet.
The adoption of qpal knucklewalking by African apes indicates that their ancient habitat went through a dry phase (rainforest became patchy) forcing a terrestrial dog-like gait.
bipedally on the ground, while non-bipedal arboreal apes also adopted
quadrupedal habits on the ground.
Bipedal walking is primitive in arboreal hominoids, quadrupedal walking is derived. I don't know of any 'non-bipedal arboreal apes', only monkeys.
gorillas, and orangutans are non-bipedal arboreal apes, meaning when >> >> >> they are in the trees, they do not walk upright.
Their body orientation on and under branches is primarily upright, not pronograde with all limbs in compression aka quadrupedal. The modern AMHs orthogonal posture is derived, not the same as primitive upright bipedal arboreal hominoids.
Please direct me to "a standard meaning of bipedalism". Afaik, bipedalism is a trait of locomoting on 2 legs in compression, whether the hands are swinging, carrying or plucking.
Sloths are quadrumanual, orangs are also called that when hanging tensionally from four limbs, but bipedal when walking on thick branches.
*human* bipedalism. But I rely on the list of diagnostic features as
described by Erika's aka Gutsick Gibbon's, who is at least one
authority. From the video you cited previously:
<https://youtu.be/jo2ZLnucuHY>
1. Foramen magnum and occipital condyles positioned anterior and
angled vertically.
2. Vertebrate lumbar lordosis.
3. Bowl-shaped pelvis with sagittally oriented iliia and anterior
iliac spine.
4. Broad sacrum.
5. Thick cortical bone around femur neck.
6. Flattened elliptical distal condyles.
7. Opterator externus groove.
8. Valgus knee.
9. Three arches of foot's sole.
Also, I note that Erika expressed the same criticism I did about your
quadrupedal human, that the foramen magnum precludes such habitual
behavior.
Rather obvious that. Yet we can do it, quickly when we have to. Our body form is closer to monkeys than to apes in some ways.
A list of features does not a meaning make.
Please direct me to "a standard meaning of bipedalism". You demanded it, I requested it.
Because there are some octopi that notoriously walk bipedally, they don't have any of those features.
BUT THEY DO WALK ON TWO LIMBS IN COMPRESSION. And **THAT** is the standard meaning of bipedalism.
So you must incorporate that into your description of human bipedalism. And so should Erika.
That's what I said.Hanging from branches using combinations of limbs isn't bipedalism any >> >> more than is climbing up coconut palms.
Suspension itself is not bipedalism.
I am unaware of any arboreal species which seasonally migrate.They weren't sessile, but very mobile.I suppose Miocene apes collected frequent-flier miles.As were most
arboreal apes prior to Australopithecines.
<https://www.britannica.com/place/Black-Sea/Climate>Again perhaps. It also suggests small bipedal arboreal apes were >> >> >> >> outcompeted.just right for the evolution of small bipedal arboreal apes.
The fact that there are no small bipedal arboreal apes in Africa indicates that there was some climate shifting.
They were, by monkeys which were more ground adapted, able to swiftly run between forest stands during a drier climate phase.
The relative position of the Black Sea didn't change from then to now.the southern Black Sea is between temperate and tropical.Correct. Southern Europe and the Black Sea are at the same latitudes.
This suggests they would tend to have the same climate. However, the
Black Sea is farther inland, and so suffers more continental extremes.
So any climate changes will appear first around the Black Sea and
become more extreme compared to southern Europe.
I'm talking about from 11ma through the MSC to 5ma. The Medit. & Red Seas dried out, the Black Sea didn't.
The important point is its position is deep in Eurasia, where
continental climates rule.
It lies between the Atlantic-Mediterranean and the Caspian Sea, in the Peri-Tethyan basin, protected by the high Iranian plateau to the south. Not a typical continental climate.
**********************************
The climate of the landlocked Black Sea can be characterized generally
as continental (i.e., subject to pronounced seasonal temperature
variations), although climatic conditions in some parts of the basin >> >> >> are controlled to a great extent by the shoreline relief. A steppe
climate, with cold winters and hot, dry summers, is found in the
northwestern part of the basin exposed to the influence of air masses >> >> >> from the north.
************************************
Summer in north including Bavaria via Danube valley, winter in south including visits further southwardly.
Songbirds? If you meant hominoids only, they are all tropical. Miocene apes had warm/cool seasons, they did migrate.
To the
best of my knowledge, although they may have a large home range, they
stick to one area throughout the year. This would suggest migrating
Miocene arboreal apes are a unique exception. Do you know of any
extant arboreal animals which seasonally migrate?
Songbirds? Which 'arboreal animals' do you mean, hominoids only?
To inform that I was stopping until i could get wifi again.Ok, stop as in "be right back". But this isn't a real-time chat.Sounds like a segue for aquatic ape hypothesis.I acknowledge that rift was one plausible pathway from Europe toMy understanding is the Mediterranean dried out only about 6mya, long
after European, and presumably Black Sea, arboreal apes went extinct.
No, Danuvius and later Miocene apes there were of one lineage IMO, that may have lived there until 5ma, with successive expansional waves emigrating outwardly including towards Africa.
The Red Sea is too far south to affect migration from Europe to Africa
regardless of climate patterns.
It is part of the African-Anatolian rift.
Africa. The Red Sea was not, nor did it block such a pathway.
I include it provisionally, more data needed.
Most proponents of that hypothesis tend to refuse to acknowledge that all extant (and by extension, archaic) Homo sleep well sheltered (dry, warm, shielded) from the elements (or try to be). Thus it is unrealistic imo.
Of course, I refer to the surrounding region, which today is hyper-arid
Another stop.No, I am speaking of climate then *and* now. Regions around 30Moving toward 30 degrees latitude, rainfall becomes seasonally dry,
and then almost continuously dry. My understanding is, the only >> >> >> >> >> native forests south of the Caspian are in the mountains, and adjacent
to the Mediterranean coasts. Arboreal apes of any kind would find
these deserts impassible.
You are speaking of recent climate. There are no arboreal apes there now.
degrees latitude tend to be drier than those around the equator, with
exceptions due to terrain and ocean currents.
Stop temporarily.
What's the point of mentioning it?
Unclear. Do you mean stop migration temporarily? If so, keep in mind
that the same climate changes which would create arid conditions
around 30 degrees latitude would also shrink forests further north and >> >> south.
You appear to be claiming that the European Miocene apes could never have been linked to African and Asian apes. Yet they certainly were, else they wouldn't have existed at all.Such an "appearance" is incorrect. In certain cases, regions around >> >> >> 30 degrees latitude have/had enough rainfall to support forests. The >> >> >> relevant point here is, global climate since the Miocene has gotten >> >> >> colder and drier, especially around 30 degrees latitude, which has led
to the creation of large areas of treeless savannah and desert. I
don't know when European and African forests separated. Do you?
Also, the question isn't about the origin of apes generally. It's
about the origin of arboreal bipedal apes. We know they existed in
Pliocene Africa. They *may* have existed in Miocene Europe. Even if >> >> >> they did, the two populations may still have evolved independently. >> >> >> >> >> To a first approximation, average rainfall and temperature are >> >> >> >> >> functions of latitude. However, while temperature is a function of
the sine of latitude, rainfall is more complex. It tends to be >> >> >> >> >> continuously heavy near the equator, continuously dry near 30 degrees,Yes.
and seasonally variable between 30 and 60 degrees. This general >> >> >> >> >> pattern is modified, sometimes dramatically, by terrain, ocean >> >> >> >> >> currents, seasons, and Milankovitch cycles.
The most significant variable is Africa's northward tectonic
migration, about a centimeter a year since before the Miocene. So,
while central Africa has moved from south to north of the equator with
little effect, north Africa has approached and then went north of 30
degrees, making it over time ever drier, amplifying other climate
trends, making once wooded areas into vast savannah and desert. >> >> >> >> >
Also, Africa's tectonic slide north almost certainly pinched closed
the Gilbraltar Sttraits, which caused the Mediterranean to dry up at
least once, and likely several times as sea levels rose and fell. The
resulting hot salt basin would also have been impassible for arboreal
apes.
This is as true now as it was in theI would not claim nor disclaim that. The Levant is near the midpoint, extends the African Rift valley to Anatolia, is a major avian migration route between Africa and Eurasia, has fossil/artifacts of Homo erectus, neanderthal & sapiens
Miocene. This suggests to me there could not have been an unbroken
forested path for arboreal apes to migrate between Europe/Near East
and Central Africa.
vertebrae. This may have caused lordosis (the normal curvature of the human spine) and moved the center of mass over the hips and legs, which implies some habitual bipedal activity.https://en.wikipedia.org/wiki/Judaean_MountainsThe regions you describe above are part of the Mediterranean coastalI acknowledge the facts you describe above. However, the Levant is
savannah and desert except for a narrow strip along the Mediterranean
and up in the mountains. While this is no problem for terrestrial
bipeds like Homo, ISTM arboreal hominids like D.guggenmosi would have
a much harder time living/migrating there.
"is".
Again, refer to microclimate of Levant 11ma - 5ma. Today's Dead Sea was once the vast brackish Lake Lisan that reached to Lebanon, a gallery forest may have reached from Anatolia to Egypt.
mountains I mentioned previously.
The Dead Sea is by no means a coastal mountain region.
These are part of a series of ranges all along the eastern
Mediterranean coast.
... which runs parallel to the Mediterranean coast.I agree a coastal Mediterranean
forest is plausible.
I'm referring to the tectonic rift valley between Zimbabwe/Zambia and Lebanon/Anatolia.
Of course, there were coastal forests as well, but they were affected by the MSC.Cite the data you think is sufficient to answer this question.
However, my understanding is the evidence is
insufficient to say if it would have been as extensive and continuous
as you suggest during the time you suggest.
Haven't got enough hard data yet.
What is ISTM?
It's shorthand acronym for "It Seems To Me"
Ok, thanks.
Danuvius, Rudapithecus, Graecopithecus, Oranopithecus each had a unique trait shared with hominins. I think of them as a superspecies with local variations.-
If you place Danuvius half-way between fast brachiating bipedal long backed long achilles tendon hylobatids and bipedal Homo with long back and long achilles tendon, it fits perfectly.
Wiki:
Danuvius is thought to have had a broad chest. It is the first recorded Miocene great ape to have had the diaphragm located in the lower chest cavity, as in Homo, indicating an extended lower back and a greater number of functional lumbar
limited ankle loading, and the ankle would have had a hinge-like function, being most stable if positioned perpendicularly to the leg as opposed to at an angle in apes. Danuvius was likely able to achieve a strong grip with its big toes, unlike modern
The robust finger and hypertrophied wrist and elbow bones indicate a strong grip and load bearing adaptations for the arms. The legs also show adaptations for load-bearing, especially at the hypertrophied knee joint. There was likely
On Sun, 20 Nov 2022 01:50:25 -0800 (PST), Daud Dedendigitigrade foot posture were proposed as anatomical correlates with speed. In addition to skeletal proportions, soft tissue and whole body proportions are important components of the locomotor system. To further distinguish patas anatomy from other Old
<daud....@gmail.com> wrote:
On Sunday, November 20, 2022 at 2:01:18 AM UTC-5, 69jp...@gmail.com wrote: >> On Sat, 19 Nov 2022 12:43:27 -0800 (PST), Daud Deden
<daud....@gmail.com> wrote:
On Saturday, November 19, 2022 at 2:20:20 PM UTC-5, 69jp...@gmail.com wrote:<inserted your reply in your later post>
On Sat, 19 Nov 2022 06:06:22 -0800 (PST), Daud Deden
<daud....@gmail.com> wrote:
On Saturday, November 19, 2022 at 6:40:01 AM UTC-5, 69jp...@gmail.com wrote:Non-hominoid species don't inform this discussion.
On Fri, 18 Nov 2022 03:45:32 -0800 (PST), Daud Deden
<daud....@gmail.com> wrote:
On Friday, November 18, 2022 at 2:12:32 AM UTC-5, 69jp...@gmail.com wrote:The positions of the muzzle and/or nose relative to the foramen magnum
On Thu, 17 Nov 2022 15:53:51 -0800 (PST), Daud Deden
<daud....@gmail.com> wrote:
On Thursday, November 17, 2022 at 12:57:57 PM UTC-5, 69jp...@gmail.com wrote:My understanding is the relative position of foramen magnum doesn't
On Wed, 16 Nov 2022 22:42:03 -0800 (PST), Daud Deden
<daud....@gmail.com> wrote:
On Thursday, November 17, 2022 at 1:29:04 AM UTC-5, Daud Deden wrote:Not sure what you mean by "mature"; the individual or the species?
On Wednesday, November 16, 2022 at 11:08:11 AM UTC-5, 69jp...@gmail.com wrote:
On Fri, 04 Nov 2022 02:21:55 -0400, jillery <69jp...@gmail.com>
wrote:
On Thu, 3 Nov 2022 20:32:40 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Thursday, November 3, 2022 at 6:29:01 PM UTC-4, 69jp...@gmail.com wrote:
On Thu, 3 Nov 2022 07:56:05 -0700 (PDT), Daud Deden >> >> >> >> >> >> > >>> <daud....@gmail.com> wrote:Yes, I claim it is *descended from* European Miocene apes of the Black Sea region.
On Tuesday, November 1, 2022 at 4:17:31 AM UTC-4, 69jp...@gmail.com wrote:Sahelanthropus tchadensis is neither Miocene nor European, but is a
On Mon, 31 Oct 2022 15:15:01 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Monday, October 24, 2022 at 2:50:22 AM UTC-4, 69jp...@gmail.com wrote:Thank you for citing the above video. It's prelude to the ones I
Gutsick Gibbon is the Youtube handle of a biological anthropology PhD-
student named Eriks. Two of her recent videos discuss some of the
latest developments relating to the origins of human bipedalism:
<https://www.youtube.com/watch?v=kbQAgPSHbZE> >> >> >> >> >> >> > >>> >> >>
The above is a link to a 32-minute video where Erika discusses several
papers relating to Sahelanthropus tchadensis. This fossil is
remarkable in part because it's dated to about 7mya and was found in
central-african Chad, and also because it may be the oldest bipedal
hominin fossil found to date. However, there appears to be strong
disagreement whether the evidence supports bipedalism.
<https://www.youtube.com/watch?v=Nwkfkp360ps> >> >> >> >> >> >> > >>> >> >>
The above is a link to a 22-minute video where Erika discusses several
hypotheses about *why* our ancestors shifted to obligate bipedalism.
She discusses several hypotheses, and presents compelling arguments
for her preferred one.
Video by Erika on Lucy bipedalism: https://youtu.be/jo2ZLnucuHY
cited, and refers to them, and so complete a logical trilogy.
In another video, she says that Sahelanthropus was the LCA of Homo / Pan, (though probably just in the general sense). https://www.youtube.com/watch?v=g4FTbZLkpzU&t=7s
In my view, Sahelanthropus is just a southwestern European Miocene ape *Descendant*, very similar to their eastern and northern kin. I see nothing palmigrade in any Miocene ape.
Pliocene central African species.
My impression is there isn't enough evidence to show whether Pliocene
African apes descended from Miocene European apes or Miocene African
apes. Either way, there was enough time between the two eras to have
evolved differences between either Miocene populations and Pliocene S.
tchadensis.
I have recently become aware of:
<https://en.wikipedia.org/wiki/Danuvius_guggenmosi>
which was a Miocene European ape that may have evolved arboreal
bipedalism similar to S.tchadensis.
Depending on how widespread its range, and how successful its
descendants, it's plausible they lived south of the Black Sea during
the late Miocene.
The question then becomes whether it's more likely these apes found
their way into Africa to become the ancestors of Pliocene
S.tchadensis, or whether S.tchadensis evolved from Miocene African
apes.
Unfortunately, the habitat of these apes made their fossil
preservation extremely rare, and so the evidence to well support
either hypothesis is lacking.
However, the question at least conditionally can be answered by
comparing the likelihood of a migratory pathway during that time,
versus the likelihood of arboreal bipedalism evolving independently in
two populations.
There are a number of anatomic features associated with arboreal
bipedalism, some of which are necessary, ex. anterior foramen magnum,
The foramen magnum is always situated relatively more anteriorly in immature than in mature apes.[ - and men. ]
Individually.
change significantly during human development.
Right. In chimps the muzzle gradually moves anteriorly relative to the foramen magnum, in Homo only the nose does.
Sorry, I erred above, I'd meant "...than in mature apes." The "and men" was NOT meant, I thought I'd erased it! Oops.
don't inform bipedalism.
It does, in tail-less upright orthogonal striding terrestrial former/partial arboreal bipeds, it does not in hopping bipeds.
Cf short-faced giant kangaroo (short tail, striding upright bipedal) >> >> The topic isn't general bipedalism, but hominoid bipedalism.
Topic: 'Human bipedalism'
Fair point. To be precise, the topic is the *origin* of human
bipedalism. But human bipedalism didn't originate in humans, but is
derived from *hominoid* ancestors like australopiths or earlier.
A version of hominoid bipedalism eg. Homo, hylobatidA version of animal bipedalism eg. T.rex
A version of primate bipedalism eg. Sifaka
A version of mammal bipedalism eg. Kangaroo
A version of animal bipedalism eg. Hoatzin (adult)
If you want to expand the discussion beyond the origins of human
bipedalism, then don't limit yourself to bipedalism; include all
animal locomotion, up to and including invertebrates. Good luck with
that.
If you want to make coherent and relevant points about the origin of
human bipedalism, then constrain your comments to Homo species and
their likely ancestors.
That is a good way to lose useful information relative to the topic, IMO. You've just erased hylobatids from the conversation. Just like Lieberman did in his endurance running H. erectus fantasy.The posts in this topic show how useful information is lost by being obscured with tangential topics. This is not to say those other
topics aren't interesting. This is not to say that meandering and
open-ended discussions aren't interesting. This is to say that IMO
the topic of the origin of human bipedalism is interesting in itself.
I hope you will join me in continuing to discuss that topic.
Adult chimps have protruding muzzles and are mostly qpal on the ground. >Adult humans have flat faces and are bipedal on the ground.
Your cited video shows an exceptional case among humans, which haveHow is that an exceptional case among hominins? Only Usain Bolt can outrun qpal chimp at top speed.Imagine how much faster that person would be if he ran normally, likeAll Homo species are great apes by definition, including H.sapiens.Either way, the important point is the position and angle of foramen
magnum are diagnostic among all vertebrates for how they habitually
hold their head, and so includes/excludes bipedalism among hominids.
Yes, but no. Great apes are bipedal except when (hurrying) on open ground they adopt quadrupedalism. Homo retains the primitive bipedal gait of hominoid ancestors, as do hylobatids.
Yes, I meant 'arboreal great apes'. Humans are terrestrial great apes, hylobatids are arboreal lesser apes.
They do/did quadrupedalism only in exceptional cases.
https://youtu.be/pCrH6BOwxe4 15mph qpal running as a patas monkey, not a chimp.
this:
<https://www.youtube.com/watch?v=k3PZgbQ8auE>
relatively short arms and long legs, anatomically maladapted for
quadrupedal locomotion.
Humans are faster qpal palm-down sprinter and qpal endurance runner than any other hominoid.
Patas monkey's arms are shorter than their legs: https://www.britannica.com/animal/patas-monkey
Locomotor Anatomy and Behavior of Patas Monkeys (Erythrocebus patas) with Comparison to Vervet Monkeys (Cercopithecus aethiops)
Adrienne L. Zihlman and Carol E. Underwood
Additional article information
Abstract
Patas monkeys (Erythrocebus patas) living in African savanna woodlands and grassland habitats have a locomotor system that allows them to run fast, presumably to avoid predators. Long fore- and hindlimbs, long foot bones, short toes, and a
adaptation that is the patas monkeys' basis for survival in grassland and savanna woodland areas.of
vervets give them access to highly dispersed, nutritious foods, water, and sleeping trees. Furthermore, patas monkeys have physiological adaptations that enable them to tolerate and dissipate heat. These features all contribute to the distinct
baboons climb trees, qpal running is just the short sprint to flight.Footraces between humans and patas monkeys are exceptional events.
Also, even though his head is in extreme
elevation, he can barely see where he's going, as his foramen magnum >> >> is anatomically maladapted for quadrupedal motion. Silly Guinness
records notwithstanding, any human moving quadrupedally from a
predator would soon become predator poop.
Why? Carrying a blade pirate-style teeth-clenched, with a few pards similarly equipped, would present predators with a serious challenge. Bipedally, better weapons could be carried, of course, but running itself isn't enough. Patas, vervet &
Predators attack from behind. There is no behind in a circle. But there is a vulnerable behind in an encircled predator. That is why the first knife slashes a rear hamstring/achilles/artery, while a pard is taunting up front, keeping the predator'sImagine yourself running quadrupedally with a blade pirate-style teeth
clenched. Now imagine yourself running out of breath and exhausted as
the predator you're running from catches up and eats you.
Don't bring a fang to a knife fight. Don't run with scissors. But most importantly, don't get encircled, because then you're prey. My pards and I run out only far enough to encircle said predator, then sing kumbaya as we slash it into ribbons of jerky.
sapiens oldest known cooking (fish .78ma) and earliest waternut gathering and bread making. The region is amenable to hominins & Homo.Fun is fun, but at least make your jokes relevant to the topic.
I acknowledge I am no authority to assert a standard meaning ofYou continue to use above a non-standard meaning of bipedalism.That's not my understanding. My understanding is chimpanzees,Perhaps. My understanding is bipedal arboreal apes continued to walk... and wet aka tropical,and some of which are incidental, ex. molar patterns. DescendantCentral Africa is and was hot,
populations are more likely to share these features than are
independent populations. This suggests to me that a sufficiently
robust fossil record could answer this question with some degree of
certainty.
Alternately, my understanding is southern Europe and central Africa
are ecological opposites, in the sense that when one is hot and dry
the other is temperate and wet.
The adoption of qpal knucklewalking by African apes indicates that their ancient habitat went through a dry phase (rainforest became patchy) forcing a terrestrial dog-like gait.
bipedally on the ground, while non-bipedal arboreal apes also adopted
quadrupedal habits on the ground.
Bipedal walking is primitive in arboreal hominoids, quadrupedal walking is derived. I don't know of any 'non-bipedal arboreal apes', only monkeys.
gorillas, and orangutans are non-bipedal arboreal apes, meaning when
they are in the trees, they do not walk upright.
Their body orientation on and under branches is primarily upright, not pronograde with all limbs in compression aka quadrupedal. The modern AMHs orthogonal posture is derived, not the same as primitive upright bipedal arboreal hominoids.
Please direct me to "a standard meaning of bipedalism". Afaik, bipedalism is a trait of locomoting on 2 legs in compression, whether the hands are swinging, carrying or plucking.
Sloths are quadrumanual, orangs are also called that when hanging tensionally from four limbs, but bipedal when walking on thick branches.
*human* bipedalism. But I rely on the list of diagnostic features as
described by Erika's aka Gutsick Gibbon's, who is at least one
authority. From the video you cited previously:
<https://youtu.be/jo2ZLnucuHY>
1. Foramen magnum and occipital condyles positioned anterior and
angled vertically.
2. Vertebrate lumbar lordosis.
3. Bowl-shaped pelvis with sagittally oriented iliia and anterior
iliac spine.
4. Broad sacrum.
5. Thick cortical bone around femur neck.
6. Flattened elliptical distal condyles.
7. Opterator externus groove.
8. Valgus knee.
9. Three arches of foot's sole.
Also, I note that Erika expressed the same criticism I did about your
quadrupedal human, that the foramen magnum precludes such habitual
behavior.
Rather obvious that. Yet we can do it, quickly when we have to. Our body form is closer to monkeys than to apes in some ways.
A list of features does not a meaning make.
Please direct me to "a standard meaning of bipedalism". You demanded it, I requested it.
Because there are some octopi that notoriously walk bipedally, they don't have any of those features.
BUT THEY DO WALK ON TWO LIMBS IN COMPRESSION. And **THAT** is the standard meaning of bipedalism.
So you must incorporate that into your description of human bipedalism. And so should Erika.
That's what I said.Hanging from branches using combinations of limbs isn't bipedalism any >> >> more than is climbing up coconut palms.
Suspension itself is not bipedalism.
I am unaware of any arboreal species which seasonally migrate.They weren't sessile, but very mobile.I suppose Miocene apes collected frequent-flier miles.As were most
arboreal apes prior to Australopithecines.
<https://www.britannica.com/place/Black-Sea/Climate>Again perhaps. It also suggests small bipedal arboreal apes were >> >> >> >> outcompeted.just right for the evolution of small bipedal arboreal apes. >> >> >> >> >The fact that there are no small bipedal arboreal apes in Africa indicates that there was some climate shifting.
They were, by monkeys which were more ground adapted, able to swiftly run between forest stands during a drier climate phase.
The relative position of the Black Sea didn't change from then to now.the southern Black Sea is between temperate and tropical. >> >> >> >> >> Correct. Southern Europe and the Black Sea are at the same latitudes.This suggests they would tend to have the same climate. However, the
Black Sea is farther inland, and so suffers more continental extremes.
So any climate changes will appear first around the Black Sea and
become more extreme compared to southern Europe.
I'm talking about from 11ma through the MSC to 5ma. The Medit. & Red Seas dried out, the Black Sea didn't.
The important point is its position is deep in Eurasia, where
continental climates rule.
It lies between the Atlantic-Mediterranean and the Caspian Sea, in the Peri-Tethyan basin, protected by the high Iranian plateau to the south. Not a typical continental climate.
**********************************
The climate of the landlocked Black Sea can be characterized generally
as continental (i.e., subject to pronounced seasonal temperature
variations), although climatic conditions in some parts of the basin
are controlled to a great extent by the shoreline relief. A steppe >> >> >> climate, with cold winters and hot, dry summers, is found in the
northwestern part of the basin exposed to the influence of air masses
from the north.
************************************
Summer in north including Bavaria via Danube valley, winter in south including visits further southwardly.
Songbirds? If you meant hominoids only, they are all tropical. Miocene apes had warm/cool seasons, they did migrate.
To the
best of my knowledge, although they may have a large home range, they
stick to one area throughout the year. This would suggest migrating
Miocene arboreal apes are a unique exception. Do you know of any
extant arboreal animals which seasonally migrate?
Songbirds? Which 'arboreal animals' do you mean, hominoids only?
To inform that I was stopping until i could get wifi again.Ok, stop as in "be right back". But this isn't a real-time chat.Sounds like a segue for aquatic ape hypothesis.I acknowledge that rift was one plausible pathway from Europe toMy understanding is the Mediterranean dried out only about 6mya, long
after European, and presumably Black Sea, arboreal apes went extinct.
No, Danuvius and later Miocene apes there were of one lineage IMO, that may have lived there until 5ma, with successive expansional waves emigrating outwardly including towards Africa.
The Red Sea is too far south to affect migration from Europe to Africa
regardless of climate patterns.
It is part of the African-Anatolian rift.
Africa. The Red Sea was not, nor did it block such a pathway.
I include it provisionally, more data needed.
Most proponents of that hypothesis tend to refuse to acknowledge that all extant (and by extension, archaic) Homo sleep well sheltered (dry, warm, shielded) from the elements (or try to be). Thus it is unrealistic imo.
Of course, I refer to the surrounding region, which today is hyper-arid >> >
Another stop.No, I am speaking of climate then *and* now. Regions around 30 >> >> >> >> degrees latitude tend to be drier than those around the equator, withMoving toward 30 degrees latitude, rainfall becomes seasonally dry,
and then almost continuously dry. My understanding is, the only
native forests south of the Caspian are in the mountains, and adjacent
to the Mediterranean coasts. Arboreal apes of any kind would find
these deserts impassible.
You are speaking of recent climate. There are no arboreal apes there now.
exceptions due to terrain and ocean currents.
Stop temporarily.
What's the point of mentioning it?
Unclear. Do you mean stop migration temporarily? If so, keep in mind >> >> that the same climate changes which would create arid conditions
around 30 degrees latitude would also shrink forests further north and >> >> south.
You appear to be claiming that the European Miocene apes could never have been linked to African and Asian apes. Yet they certainly were, else they wouldn't have existed at all.Such an "appearance" is incorrect. In certain cases, regions around >> >> >> 30 degrees latitude have/had enough rainfall to support forests. The
relevant point here is, global climate since the Miocene has gotten >> >> >> colder and drier, especially around 30 degrees latitude, which has led
to the creation of large areas of treeless savannah and desert. I >> >> >> don't know when European and African forests separated. Do you?
Also, the question isn't about the origin of apes generally. It's >> >> >> about the origin of arboreal bipedal apes. We know they existed in >> >> >> Pliocene Africa. They *may* have existed in Miocene Europe. Even if >> >> >> they did, the two populations may still have evolved independently. >> >> >> >> >> To a first approximation, average rainfall and temperature are
functions of latitude. However, while temperature is a function of
the sine of latitude, rainfall is more complex. It tends to be
continuously heavy near the equator, continuously dry near 30 degrees,
and seasonally variable between 30 and 60 degrees. This general
pattern is modified, sometimes dramatically, by terrain, ocean
currents, seasons, and Milankovitch cycles.
The most significant variable is Africa's northward tectonic >> >> >> >> >> migration, about a centimeter a year since before the Miocene. So,
while central Africa has moved from south to north of the equator with
little effect, north Africa has approached and then went north of 30
degrees, making it over time ever drier, amplifying other climate
trends, making once wooded areas into vast savannah and desert.
Yes.
Also, Africa's tectonic slide north almost certainly pinched closed
the Gilbraltar Sttraits, which caused the Mediterranean to dry up at
least once, and likely several times as sea levels rose and fell. The
resulting hot salt basin would also have been impassible for arboreal
apes.
This is as true now as it was in theI would not claim nor disclaim that. The Levant is near the midpoint, extends the African Rift valley to Anatolia, is a major avian migration route between Africa and Eurasia, has fossil/artifacts of Homo erectus, neanderthal &
Miocene. This suggests to me there could not have been an unbroken
forested path for arboreal apes to migrate between Europe/Near East
and Central Africa.
lumbar vertebrae. This may have caused lordosis (the normal curvature of the human spine) and moved the center of mass over the hips and legs, which implies some habitual bipedal activity.https://en.wikipedia.org/wiki/Judaean_MountainsThe regions you describe above are part of the Mediterranean coastalI acknowledge the facts you describe above. However, the Levant is
savannah and desert except for a narrow strip along the Mediterranean
and up in the mountains. While this is no problem for terrestrial
bipeds like Homo, ISTM arboreal hominids like D.guggenmosi would have
a much harder time living/migrating there.
"is".
Again, refer to microclimate of Levant 11ma - 5ma. Today's Dead Sea was once the vast brackish Lake Lisan that reached to Lebanon, a gallery forest may have reached from Anatolia to Egypt.
mountains I mentioned previously.
The Dead Sea is by no means a coastal mountain region.
These are part of a series of ranges all along the eastern
Mediterranean coast.
... which runs parallel to the Mediterranean coast.I agree a coastal Mediterranean
forest is plausible.
I'm referring to the tectonic rift valley between Zimbabwe/Zambia and Lebanon/Anatolia.
Of course, there were coastal forests as well, but they were affected by the MSC.Cite the data you think is sufficient to answer this question.
However, my understanding is the evidence is
insufficient to say if it would have been as extensive and continuous
as you suggest during the time you suggest.
Haven't got enough hard data yet.
What is ISTM?
It's shorthand acronym for "It Seems To Me"
Ok, thanks.
Danuvius, Rudapithecus, Graecopithecus, Oranopithecus each had a unique trait shared with hominins. I think of them as a superspecies with local variations.-
If you place Danuvius half-way between fast brachiating bipedal long backed long achilles tendon hylobatids and bipedal Homo with long back and long achilles tendon, it fits perfectly.
Wiki:
Danuvius is thought to have had a broad chest. It is the first recorded Miocene great ape to have had the diaphragm located in the lower chest cavity, as in Homo, indicating an extended lower back and a greater number of functional
limited ankle loading, and the ankle would have had a hinge-like function, being most stable if positioned perpendicularly to the leg as opposed to at an angle in apes. Danuvius was likely able to achieve a strong grip with its big toes, unlike modern
The robust finger and hypertrophied wrist and elbow bones indicate a strong grip and load bearing adaptations for the arms. The legs also show adaptations for load-bearing, especially at the hypertrophied knee joint. There was likely
So far, you have offered up a 'parts list' of human bipedalism features, in response to my request for "a standard meaning of bipedalism". A list of features does not a meaning make, in my experience. In all of my conversations with others about Biology*or* Engineering, I have never heard of a list of parts being referred to as a "standard meaning of" anything. A "standard measure" perhaps, but not a standard meaning.
Perhaps Erika will inform what the 'standard meaning of bipedalism' is, since you rely on her authority, in addition to the parts list. But I can't see how to improve the simple statement given, "two limbs in compression", when applied to whichever theanimate taxon under discussion.
On Mon, 21 Nov 2022 00:31:25 -0800 (PST), Daud DedenBiology *or* Engineering, I have never heard of a list of parts being referred to as a "standard meaning of" anything. A "standard measure" perhaps, but not a standard meaning.
<daud.deden@gmail.com> wrote:
So far, you have offered up a 'parts list' of human bipedalism features, in response to my request for "a standard meaning of bipedalism". A list of features does not a meaning make, in my experience. In all of my conversations with others about
animate taxon under discussion.Perhaps Erika will inform what the 'standard meaning of bipedalism' is, since you rely on her authority, in addition to the parts list. But I can't see how to improve the simple statement given, "two limbs in compression", when applied to whichever the
What is in dispute here is not the meaning of bipedalism, but instead
what is the topic under discussion. I am interested in discussing the
origin of human bipedalism. Are you?
On Mon, 21 Nov 2022 00:31:25 -0800 (PST), Daud DedenBiology *or* Engineering, I have never heard of a list of parts being referred to as a "standard meaning of" anything. A "standard measure" perhaps, but not a standard meaning.
<daud....@gmail.com> wrote:
So far, you have offered up a 'parts list' of human bipedalism features, in response to my request for "a standard meaning of bipedalism". A list of features does not a meaning make, in my experience. In all of my conversations with others about
the animate taxon under discussion.Perhaps Erika will inform what the 'standard meaning of bipedalism' is, since you rely on her authority, in addition to the parts list. But I can't see how to improve the simple statement given, "two limbs in compression", when applied to whichever
What is in dispute here is not the meaning of bipedalism, but insteadI simply clarified my position, as you did yours and Erika's. I don't view that as dispute. Different strokes/steps/opinions for different folks. IMO human bipedalism preceded humans (Homo of Chr. 2 split), and it has continued to evolve, step by step.
what is the topic under discussion. I am interested in discussing the
origin of human bipedalism. Are you?
On Mon, 21 Nov 2022 06:44:37 -0500, jillery <69jp...@gmail.com>Biology *or* Engineering, I have never heard of a list of parts being referred to as a "standard meaning of" anything. A "standard measure" perhaps, but not a standard meaning.
wrote:
On Mon, 21 Nov 2022 00:31:25 -0800 (PST), Daud Deden
<daud....@gmail.com> wrote:
So far, you have offered up a 'parts list' of human bipedalism features, in response to my request for "a standard meaning of bipedalism". A list of features does not a meaning make, in my experience. In all of my conversations with others about
the animate taxon under discussion.Perhaps Erika will inform what the 'standard meaning of bipedalism' is, since you rely on her authority, in addition to the parts list. But I can't see how to improve the simple statement given, "two limbs in compression", when applied to whichever
What is in dispute here is not the meaning of bipedalism, but insteadApparently you were but are no longer. I acknowledge your comments
what is the topic under discussion. I am interested in discussing the >origin of human bipedalism. Are you?
were interesting when you were.
On Tuesday, November 22, 2022 at 1:20:03 AM UTC-5, 69jp...@gmail.com wrote:Biology *or* Engineering, I have never heard of a list of parts being referred to as a "standard meaning of" anything. A "standard measure" perhaps, but not a standard meaning.
On Mon, 21 Nov 2022 06:44:37 -0500, jillery <69jp...@gmail.com>
wrote:
On Mon, 21 Nov 2022 00:31:25 -0800 (PST), Daud Deden ><daud....@gmail.com> wrote:
So far, you have offered up a 'parts list' of human bipedalism features, in response to my request for "a standard meaning of bipedalism". A list of features does not a meaning make, in my experience. In all of my conversations with others about
the animate taxon under discussion.Perhaps Erika will inform what the 'standard meaning of bipedalism' is, since you rely on her authority, in addition to the parts list. But I can't see how to improve the simple statement given, "two limbs in compression", when applied to whichever
-Yes, for decades past and decades into the future, discontinuously. There are other things that pop up that require attention.What is in dispute here is not the meaning of bipedalism, but instead >what is the topic under discussion. I am interested in discussing the >origin of human bipedalism. Are you?Apparently you were but are no longer. I acknowledge your comments
were interesting when you were.
On Sunday, November 20, 2022 at 4:50:27 AM UTC-5, Daud Deden wrote:
On Sunday, November 20, 2022 at 2:01:18 AM UTC-5, 69jp...@gmail.com wrote:
On Sat, 19 Nov 2022 12:43:27 -0800 (PST), Daud Deden <daud....@gmail.com> wrote:
On Saturday, November 19, 2022 at 2:20:20 PM UTC-5, 69jp...@gmail.com wrote:<inserted your reply in your later post>
On Sat, 19 Nov 2022 06:06:22 -0800 (PST), Daud Deden
<daud....@gmail.com> wrote:
On Saturday, November 19, 2022 at 6:40:01 AM UTC-5, 69jp...@gmail.com wrote:Non-hominoid species don't inform this discussion.
On Fri, 18 Nov 2022 03:45:32 -0800 (PST), Daud Deden
<daud....@gmail.com> wrote:
On Friday, November 18, 2022 at 2:12:32 AM UTC-5, 69jp...@gmail.com wrote:The positions of the muzzle and/or nose relative to the foramen magnum
On Thu, 17 Nov 2022 15:53:51 -0800 (PST), Daud Deden
<daud....@gmail.com> wrote:
On Thursday, November 17, 2022 at 12:57:57 PM UTC-5, 69jp...@gmail.com wrote:My understanding is the relative position of foramen magnum doesn't
On Wed, 16 Nov 2022 22:42:03 -0800 (PST), Daud Deden
<daud....@gmail.com> wrote:
On Thursday, November 17, 2022 at 1:29:04 AM UTC-5, Daud Deden wrote:Not sure what you mean by "mature"; the individual or the species?
On Wednesday, November 16, 2022 at 11:08:11 AM UTC-5, 69jp...@gmail.com wrote:
On Fri, 04 Nov 2022 02:21:55 -0400, jillery <69jp...@gmail.com>
wrote:
On Thu, 3 Nov 2022 20:32:40 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Thursday, November 3, 2022 at 6:29:01 PM UTC-4, 69jp...@gmail.com wrote:
On Thu, 3 Nov 2022 07:56:05 -0700 (PDT), Daud Deden >> >> >> >> >> > >>> <daud....@gmail.com> wrote:Yes, I claim it is *descended from* European Miocene apes of the Black Sea region.
On Tuesday, November 1, 2022 at 4:17:31 AM UTC-4, 69jp...@gmail.com wrote:Sahelanthropus tchadensis is neither Miocene nor European, but is a
On Mon, 31 Oct 2022 15:15:01 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Monday, October 24, 2022 at 2:50:22 AM UTC-4, 69jp...@gmail.com wrote:Thank you for citing the above video. It's prelude to the ones I
Gutsick Gibbon is the Youtube handle of a biological anthropology PhD-
student named Eriks. Two of her recent videos discuss some of the
latest developments relating to the origins of human bipedalism:
<https://www.youtube.com/watch?v=kbQAgPSHbZE> >> >> >> >> >> > >>> >> >>
The above is a link to a 32-minute video where Erika discusses several
papers relating to Sahelanthropus tchadensis. This fossil is
remarkable in part because it's dated to about 7mya and was found in
central-african Chad, and also because it may be the oldest bipedal
hominin fossil found to date. However, there appears to be strong
disagreement whether the evidence supports bipedalism.
<https://www.youtube.com/watch?v=Nwkfkp360ps> >> >> >> >> >> > >>> >> >>
The above is a link to a 22-minute video where Erika discusses several
hypotheses about *why* our ancestors shifted to obligate bipedalism.
She discusses several hypotheses, and presents compelling arguments
for her preferred one.
Video by Erika on Lucy bipedalism: https://youtu.be/jo2ZLnucuHY
cited, and refers to them, and so complete a logical trilogy.
In another video, she says that Sahelanthropus was the LCA of Homo / Pan, (though probably just in the general sense). https://www.youtube.com/watch?v=g4FTbZLkpzU&t=7s
In my view, Sahelanthropus is just a southwestern European Miocene ape *Descendant*, very similar to their eastern and northern kin. I see nothing palmigrade in any Miocene ape.
Pliocene central African species.
My impression is there isn't enough evidence to show whether Pliocene
African apes descended from Miocene European apes or Miocene African
apes. Either way, there was enough time between the two eras to have
evolved differences between either Miocene populations and Pliocene S.
tchadensis.
I have recently become aware of:
<https://en.wikipedia.org/wiki/Danuvius_guggenmosi>
which was a Miocene European ape that may have evolved arboreal
bipedalism similar to S.tchadensis.
Depending on how widespread its range, and how successful its
descendants, it's plausible they lived south of the Black Sea during
the late Miocene.
The question then becomes whether it's more likely these apes found
their way into Africa to become the ancestors of Pliocene
S.tchadensis, or whether S.tchadensis evolved from Miocene African
apes.
Unfortunately, the habitat of these apes made their fossil
preservation extremely rare, and so the evidence to well support
either hypothesis is lacking.
However, the question at least conditionally can be answered by
comparing the likelihood of a migratory pathway during that time,
versus the likelihood of arboreal bipedalism evolving independently in
two populations.
There are a number of anatomic features associated with arboreal
bipedalism, some of which are necessary, ex. anterior foramen magnum,
The foramen magnum is always situated relatively more anteriorly in immature than in mature apes.[ - and men. ]
Individually.
change significantly during human development.
Right. In chimps the muzzle gradually moves anteriorly relative to the foramen magnum, in Homo only the nose does.
Sorry, I erred above, I'd meant "...than in mature apes." The "and men" was NOT meant, I thought I'd erased it! Oops.
don't inform bipedalism.
It does, in tail-less upright orthogonal striding terrestrial former/partial arboreal bipeds, it does not in hopping bipeds.
Cf short-faced giant kangaroo (short tail, striding upright bipedal) >> The topic isn't general bipedalism, but hominoid bipedalism.
Topic: 'Human bipedalism'
digitigrade foot posture were proposed as anatomical correlates with speed. In addition to skeletal proportions, soft tissue and whole body proportions are important components of the locomotor system. To further distinguish patas anatomy from other OldFair point. To be precise, the topic is the *origin* of human bipedalism. But human bipedalism didn't originate in humans, but is derived from *hominoid* ancestors like australopiths or earlier.
A version of hominoid bipedalism eg. Homo, hylobatidA version of animal bipedalism eg. T.rex
A version of primate bipedalism eg. Sifaka
A version of mammal bipedalism eg. Kangaroo
A version of animal bipedalism eg. Hoatzin (adult)
If you want to expand the discussion beyond the origins of human bipedalism, then don't limit yourself to bipedalism; include allThat is a good way to lose useful information relative to the topic, IMO. You've just erased hylobatids from the conversation. Just like Lieberman did in his endurance running H. erectus fantasy.
animal locomotion, up to and including invertebrates. Good luck with that.
If you want to make coherent and relevant points about the origin of human bipedalism, then constrain your comments to Homo species and
their likely ancestors.
Adult chimps have protruding muzzles and are mostly qpal on the ground. Adult humans have flat faces and are bipedal on the ground.
Your cited video shows an exceptional case among humans, which have >> relatively short arms and long legs, anatomically maladapted forHow is that an exceptional case among hominins? Only Usain Bolt can outrun qpal chimp at top speed.Imagine how much faster that person would be if he ran normally, likeAll Homo species are great apes by definition, including H.sapiens.Either way, the important point is the position and angle of foramen
magnum are diagnostic among all vertebrates for how they habitually
hold their head, and so includes/excludes bipedalism among hominids.
Yes, but no. Great apes are bipedal except when (hurrying) on open ground they adopt quadrupedalism. Homo retains the primitive bipedal gait of hominoid ancestors, as do hylobatids.
Yes, I meant 'arboreal great apes'. Humans are terrestrial great apes, hylobatids are arboreal lesser apes.
They do/did quadrupedalism only in exceptional cases.
https://youtu.be/pCrH6BOwxe4 15mph qpal running as a patas monkey, not a chimp.
this:
<https://www.youtube.com/watch?v=k3PZgbQ8auE>
quadrupedal locomotion.
Humans are faster qpal palm-down sprinter and qpal endurance runner than any other hominoid.
Patas monkey's arms are shorter than their legs: https://www.britannica.com/animal/patas-monkey
Locomotor Anatomy and Behavior of Patas Monkeys (Erythrocebus patas) with Comparison to Vervet Monkeys (Cercopithecus aethiops)
Adrienne L. Zihlman and Carol E. Underwood
Additional article information
Abstract
Patas monkeys (Erythrocebus patas) living in African savanna woodlands and grassland habitats have a locomotor system that allows them to run fast, presumably to avoid predators. Long fore- and hindlimbs, long foot bones, short toes, and a
adaptation that is the patas monkeys' basis for survival in grassland and savanna woodland areas.vervets give them access to highly dispersed, nutritious foods, water, and sleeping trees. Furthermore, patas monkeys have physiological adaptations that enable them to tolerate and dissipate heat. These features all contribute to the distinct
baboons climb trees, qpal running is just the short sprint to flight.Footraces between humans and patas monkeys are exceptional events.
Also, even though his head is in extreme
elevation, he can barely see where he's going, as his foramen magnum >> is anatomically maladapted for quadrupedal motion. Silly Guinness
records notwithstanding, any human moving quadrupedally from a
predator would soon become predator poop.
Why? Carrying a blade pirate-style teeth-clenched, with a few pards similarly equipped, would present predators with a serious challenge. Bipedally, better weapons could be carried, of course, but running itself isn't enough. Patas, vervet &
jerky. Predators attack from behind. There is no behind in a circle. But there is a vulnerable behind in an encircled predator. That is why the first knife slashes a rear hamstring/achilles/artery, while a pard is taunting up front, keeping the predator'Imagine yourself running quadrupedally with a blade pirate-style teeth clenched. Now imagine yourself running out of breath and exhausted as the predator you're running from catches up and eats you.Don't bring a fang to a knife fight. Don't run with scissors. But most importantly, don't get encircled, because then you're prey. My pards and I run out only far enough to encircle said predator, then sing kumbaya as we slash it into ribbons of
Fun is fun, but at least make your jokes relevant to the topic.
You continue to use above a non-standard meaning of bipedalism.That's not my understanding. My understanding is chimpanzees,Perhaps. My understanding is bipedal arboreal apes continued to walk... and wet aka tropical,and some of which are incidental, ex. molar patterns. DescendantCentral Africa is and was hot,
populations are more likely to share these features than are
independent populations. This suggests to me that a sufficiently
robust fossil record could answer this question with some degree of
certainty.
Alternately, my understanding is southern Europe and central Africa
are ecological opposites, in the sense that when one is hot and dry
the other is temperate and wet.
The adoption of qpal knucklewalking by African apes indicates that their ancient habitat went through a dry phase (rainforest became patchy) forcing a terrestrial dog-like gait.
bipedally on the ground, while non-bipedal arboreal apes also adopted
quadrupedal habits on the ground.
Bipedal walking is primitive in arboreal hominoids, quadrupedal walking is derived. I don't know of any 'non-bipedal arboreal apes', only monkeys.
gorillas, and orangutans are non-bipedal arboreal apes, meaning when
they are in the trees, they do not walk upright.
Their body orientation on and under branches is primarily upright, not pronograde with all limbs in compression aka quadrupedal. The modern AMHs orthogonal posture is derived, not the same as primitive upright bipedal arboreal hominoids.
Please direct me to "a standard meaning of bipedalism". Afaik, bipedalism is a trait of locomoting on 2 legs in compression, whether the hands are swinging, carrying or plucking.I acknowledge I am no authority to assert a standard meaning of
Sloths are quadrumanual, orangs are also called that when hanging tensionally from four limbs, but bipedal when walking on thick branches.
*human* bipedalism. But I rely on the list of diagnostic features as described by Erika's aka Gutsick Gibbon's, who is at least one authority. From the video you cited previously:
<https://youtu.be/jo2ZLnucuHY>
1. Foramen magnum and occipital condyles positioned anterior and
angled vertically.
2. Vertebrate lumbar lordosis.
3. Bowl-shaped pelvis with sagittally oriented iliia and anterior
iliac spine.
4. Broad sacrum.
5. Thick cortical bone around femur neck.
6. Flattened elliptical distal condyles.
7. Opterator externus groove.
8. Valgus knee.
9. Three arches of foot's sole.
Also, I note that Erika expressed the same criticism I did about your quadrupedal human, that the foramen magnum precludes such habitual behavior.Rather obvious that. Yet we can do it, quickly when we have to. Our body form is closer to monkeys than to apes in some ways.
A list of features does not a meaning make.
Please direct me to "a standard meaning of bipedalism". You demanded it, I requested it.
Because there are some octopi that notoriously walk bipedally, they don't have any of those features.
BUT THEY DO WALK ON TWO LIMBS IN COMPRESSION. And **THAT** is the standard meaning of bipedalism.
So you must incorporate that into your description of human bipedalism. And so should Erika.
Hanging from branches using combinations of limbs isn't bipedalism any
more than is climbing up coconut palms.
Songbirds? If you meant hominoids only, they are all tropical. Miocene apes had warm/cool seasons, they did migrate.Suspension itself is not bipedalism.That's what I said.
I am unaware of any arboreal species which seasonally migrate.They weren't sessile, but very mobile.I suppose Miocene apes collected frequent-flier miles.As were most
arboreal apes prior to Australopithecines.
<https://www.britannica.com/place/Black-Sea/Climate>Again perhaps. It also suggests small bipedal arboreal apes werejust right for the evolution of small bipedal arboreal apes. >> >> >> >The fact that there are no small bipedal arboreal apes in Africa indicates that there was some climate shifting.
outcompeted.
They were, by monkeys which were more ground adapted, able to swiftly run between forest stands during a drier climate phase.
The relative position of the Black Sea didn't change from then to now.the southern Black Sea is between temperate and tropical. >> >> >> >> Correct. Southern Europe and the Black Sea are at the same latitudes.This suggests they would tend to have the same climate. However, the
Black Sea is farther inland, and so suffers more continental extremes.
So any climate changes will appear first around the Black Sea and
become more extreme compared to southern Europe.
I'm talking about from 11ma through the MSC to 5ma. The Medit. & Red Seas dried out, the Black Sea didn't.
The important point is its position is deep in Eurasia, where >> >> >> continental climates rule.
It lies between the Atlantic-Mediterranean and the Caspian Sea, in the Peri-Tethyan basin, protected by the high Iranian plateau to the south. Not a typical continental climate.
**********************************
The climate of the landlocked Black Sea can be characterized generally
as continental (i.e., subject to pronounced seasonal temperature >> >> variations), although climatic conditions in some parts of the basin
are controlled to a great extent by the shoreline relief. A steppe >> >> climate, with cold winters and hot, dry summers, is found in the >> >> northwestern part of the basin exposed to the influence of air masses
from the north.
************************************
Summer in north including Bavaria via Danube valley, winter in south including visits further southwardly.
To the
best of my knowledge, although they may have a large home range, they stick to one area throughout the year. This would suggest migrating Miocene arboreal apes are a unique exception. Do you know of anySongbirds? Which 'arboreal animals' do you mean, hominoids only?
extant arboreal animals which seasonally migrate?
Sounds like a segue for aquatic ape hypothesis.I acknowledge that rift was one plausible pathway from Europe to >> >> Africa. The Red Sea was not, nor did it block such a pathway.My understanding is the Mediterranean dried out only about 6mya, long
after European, and presumably Black Sea, arboreal apes went extinct.
No, Danuvius and later Miocene apes there were of one lineage IMO, that may have lived there until 5ma, with successive expansional waves emigrating outwardly including towards Africa.
The Red Sea is too far south to affect migration from Europe to Africa
regardless of climate patterns.
It is part of the African-Anatolian rift.
I include it provisionally, more data needed.
Most proponents of that hypothesis tend to refuse to acknowledge that all extant (and by extension, archaic) Homo sleep well sheltered (dry, warm, shielded) from the elements (or try to be). Thus it is unrealistic imo.
Of course, I refer to the surrounding region, which today is hyper-arid
sapiens oldest known cooking (fish .78ma) and earliest waternut gathering and bread making. The region is amenable to hominins & Homo.To inform that I was stopping until i could get wifi again.Ok, stop as in "be right back". But this isn't a real-time chat.Another stop.No, I am speaking of climate then *and* now. Regions around 30 >> >> >> degrees latitude tend to be drier than those around the equator, withMoving toward 30 degrees latitude, rainfall becomes seasonally dry,
and then almost continuously dry. My understanding is, the only
native forests south of the Caspian are in the mountains, and adjacent
to the Mediterranean coasts. Arboreal apes of any kind would find
these deserts impassible.
You are speaking of recent climate. There are no arboreal apes there now.
exceptions due to terrain and ocean currents.
Stop temporarily.
What's the point of mentioning it?
Unclear. Do you mean stop migration temporarily? If so, keep in mind >> that the same climate changes which would create arid conditions
around 30 degrees latitude would also shrink forests further north and
south.
You appear to be claiming that the European Miocene apes could never have been linked to African and Asian apes. Yet they certainly were, else they wouldn't have existed at all.Such an "appearance" is incorrect. In certain cases, regions around
30 degrees latitude have/had enough rainfall to support forests. The
relevant point here is, global climate since the Miocene has gotten
colder and drier, especially around 30 degrees latitude, which has led
to the creation of large areas of treeless savannah and desert. I >> >> don't know when European and African forests separated. Do you?
Also, the question isn't about the origin of apes generally. It's >> >> about the origin of arboreal bipedal apes. We know they existed in >> >> Pliocene Africa. They *may* have existed in Miocene Europe. Even if
they did, the two populations may still have evolved independently.
To a first approximation, average rainfall and temperature are
functions of latitude. However, while temperature is a function of
the sine of latitude, rainfall is more complex. It tends to be
continuously heavy near the equator, continuously dry near 30 degrees,
and seasonally variable between 30 and 60 degrees. This general
pattern is modified, sometimes dramatically, by terrain, ocean
currents, seasons, and Milankovitch cycles.
The most significant variable is Africa's northward tectonic >> >> >> >> migration, about a centimeter a year since before the Miocene. So,
while central Africa has moved from south to north of the equator with
little effect, north Africa has approached and then went north of 30
degrees, making it over time ever drier, amplifying other climate
trends, making once wooded areas into vast savannah and desert.
Yes.
Also, Africa's tectonic slide north almost certainly pinched closed
the Gilbraltar Sttraits, which caused the Mediterranean to dry up at
least once, and likely several times as sea levels rose and fell. The
resulting hot salt basin would also have been impassible for arboreal
apes.
This is as true now as it was in theI would not claim nor disclaim that. The Levant is near the midpoint, extends the African Rift valley to Anatolia, is a major avian migration route between Africa and Eurasia, has fossil/artifacts of Homo erectus, neanderthal &
Miocene. This suggests to me there could not have been an unbroken
forested path for arboreal apes to migrate between Europe/Near East
and Central Africa.
lumbar vertebrae. This may have caused lordosis (the normal curvature of the human spine) and moved the center of mass over the hips and legs, which implies some habitual bipedal activity.https://en.wikipedia.org/wiki/Judaean_MountainsThe regions you describe above are part of the Mediterranean coastalI acknowledge the facts you describe above. However, the Levant is
savannah and desert except for a narrow strip along the Mediterranean
and up in the mountains. While this is no problem for terrestrial
bipeds like Homo, ISTM arboreal hominids like D.guggenmosi would have
a much harder time living/migrating there.
"is".
Again, refer to microclimate of Levant 11ma - 5ma. Today's Dead Sea was once the vast brackish Lake Lisan that reached to Lebanon, a gallery forest may have reached from Anatolia to Egypt.
mountains I mentioned previously.
The Dead Sea is by no means a coastal mountain region.
These are part of a series of ranges all along the eastern
Mediterranean coast.
... which runs parallel to the Mediterranean coast.I agree a coastal Mediterranean
forest is plausible.
I'm referring to the tectonic rift valley between Zimbabwe/Zambia and Lebanon/Anatolia.
Of course, there were coastal forests as well, but they were affected by the MSC.Cite the data you think is sufficient to answer this question.
However, my understanding is the evidence is
insufficient to say if it would have been as extensive and continuous
as you suggest during the time you suggest.
Haven't got enough hard data yet.
What is ISTM?
It's shorthand acronym for "It Seems To Me"
Ok, thanks.
Danuvius, Rudapithecus, Graecopithecus, Oranopithecus each had a unique trait shared with hominins. I think of them as a superspecies with local variations.-
If you place Danuvius half-way between fast brachiating bipedal long backed long achilles tendon hylobatids and bipedal Homo with long back and long achilles tendon, it fits perfectly.
Wiki:
Danuvius is thought to have had a broad chest. It is the first recorded Miocene great ape to have had the diaphragm located in the lower chest cavity, as in Homo, indicating an extended lower back and a greater number of functional
limited ankle loading, and the ankle would have had a hinge-like function, being most stable if positioned perpendicularly to the leg as opposed to at an angle in apes. Danuvius was likely able to achieve a strong grip with its big toes, unlike modern
The robust finger and hypertrophied wrist and elbow bones indicate a strong grip and load bearing adaptations for the arms. The legs also show adaptations for load-bearing, especially at the hypertrophied knee joint. There was likely
----
Q: Alex, what is Sifaka?
On Sunday, November 20, 2022 at 11:26:11 PM UTC-5, Daud Deden wrote:
On Sunday, November 20, 2022 at 4:50:27 AM UTC-5, Daud Deden wrote:
On Sunday, November 20, 2022 at 2:01:18 AM UTC-5, 69jp...@gmail.com wrote:
On Sat, 19 Nov 2022 12:43:27 -0800 (PST), Daud Deden <daud....@gmail.com> wrote:
On Saturday, November 19, 2022 at 2:20:20 PM UTC-5, 69jp...@gmail.com wrote:<inserted your reply in your later post>
On Sat, 19 Nov 2022 06:06:22 -0800 (PST), Daud Deden
<daud....@gmail.com> wrote:
On Saturday, November 19, 2022 at 6:40:01 AM UTC-5, 69jp...@gmail.com wrote:The topic isn't general bipedalism, but hominoid bipedalism.
On Fri, 18 Nov 2022 03:45:32 -0800 (PST), Daud Deden
<daud....@gmail.com> wrote:
On Friday, November 18, 2022 at 2:12:32 AM UTC-5, 69jp...@gmail.com wrote:The positions of the muzzle and/or nose relative to the foramen magnum
On Thu, 17 Nov 2022 15:53:51 -0800 (PST), Daud Deden
<daud....@gmail.com> wrote:
On Thursday, November 17, 2022 at 12:57:57 PM UTC-5, 69jp...@gmail.com wrote:My understanding is the relative position of foramen magnum doesn't
On Wed, 16 Nov 2022 22:42:03 -0800 (PST), Daud Deden
<daud....@gmail.com> wrote:
On Thursday, November 17, 2022 at 1:29:04 AM UTC-5, Daud Deden wrote:Not sure what you mean by "mature"; the individual or the species?
On Wednesday, November 16, 2022 at 11:08:11 AM UTC-5, 69jp...@gmail.com wrote:
On Fri, 04 Nov 2022 02:21:55 -0400, jillery <69jp...@gmail.com>
wrote:
On Thu, 3 Nov 2022 20:32:40 -0700 (PDT), Daud Deden >> >> >> >> >> > ><daud....@gmail.com> wrote:
On Thursday, November 3, 2022 at 6:29:01 PM UTC-4, 69jp...@gmail.com wrote:
On Thu, 3 Nov 2022 07:56:05 -0700 (PDT), Daud DedenYes, I claim it is *descended from* European Miocene apes of the Black Sea region.
<daud....@gmail.com> wrote:
On Tuesday, November 1, 2022 at 4:17:31 AM UTC-4, 69jp...@gmail.com wrote:Sahelanthropus tchadensis is neither Miocene nor European, but is a
On Mon, 31 Oct 2022 15:15:01 -0700 (PDT), Daud Deden
<daud....@gmail.com> wrote:
On Monday, October 24, 2022 at 2:50:22 AM UTC-4, 69jp...@gmail.com wrote:Thank you for citing the above video. It's prelude to the ones I
Gutsick Gibbon is the Youtube handle of a biological anthropology PhD-
student named Eriks. Two of her recent videos discuss some of the
latest developments relating to the origins of human bipedalism:
<https://www.youtube.com/watch?v=kbQAgPSHbZE>
The above is a link to a 32-minute video where Erika discusses several
papers relating to Sahelanthropus tchadensis. This fossil is
remarkable in part because it's dated to about 7mya and was found in
central-african Chad, and also because it may be the oldest bipedal
hominin fossil found to date. However, there appears to be strong
disagreement whether the evidence supports bipedalism.
<https://www.youtube.com/watch?v=Nwkfkp360ps>
The above is a link to a 22-minute video where Erika discusses several
hypotheses about *why* our ancestors shifted to obligate bipedalism.
She discusses several hypotheses, and presents compelling arguments
for her preferred one.
Video by Erika on Lucy bipedalism: https://youtu.be/jo2ZLnucuHY
cited, and refers to them, and so complete a logical trilogy.
In another video, she says that Sahelanthropus was the LCA of Homo / Pan, (though probably just in the general sense). https://www.youtube.com/watch?v=g4FTbZLkpzU&t=7s
In my view, Sahelanthropus is just a southwestern European Miocene ape *Descendant*, very similar to their eastern and northern kin. I see nothing palmigrade in any Miocene ape.
Pliocene central African species.
My impression is there isn't enough evidence to show whether Pliocene
African apes descended from Miocene European apes or Miocene African
apes. Either way, there was enough time between the two eras to have
evolved differences between either Miocene populations and Pliocene S.
tchadensis.
I have recently become aware of:
<https://en.wikipedia.org/wiki/Danuvius_guggenmosi> >> >> >> >> >> >
which was a Miocene European ape that may have evolved arboreal
bipedalism similar to S.tchadensis.
Depending on how widespread its range, and how successful its
descendants, it's plausible they lived south of the Black Sea during
the late Miocene.
The question then becomes whether it's more likely these apes found
their way into Africa to become the ancestors of Pliocene
S.tchadensis, or whether S.tchadensis evolved from Miocene African
apes.
Unfortunately, the habitat of these apes made their fossil
preservation extremely rare, and so the evidence to well support
either hypothesis is lacking.
However, the question at least conditionally can be answered by
comparing the likelihood of a migratory pathway during that time,
versus the likelihood of arboreal bipedalism evolving independently in
two populations.
There are a number of anatomic features associated with arboreal
bipedalism, some of which are necessary, ex. anterior foramen magnum,
The foramen magnum is always situated relatively more anteriorly in immature than in mature apes.[ - and men. ]
Individually.
change significantly during human development.
Right. In chimps the muzzle gradually moves anteriorly relative to the foramen magnum, in Homo only the nose does.
Sorry, I erred above, I'd meant "...than in mature apes." The "and men" was NOT meant, I thought I'd erased it! Oops.
don't inform bipedalism.
It does, in tail-less upright orthogonal striding terrestrial former/partial arboreal bipeds, it does not in hopping bipeds.
Cf short-faced giant kangaroo (short tail, striding upright bipedal)
Non-hominoid species don't inform this discussion.
Topic: 'Human bipedalism'
digitigrade foot posture were proposed as anatomical correlates with speed. In addition to skeletal proportions, soft tissue and whole body proportions are important components of the locomotor system. To further distinguish patas anatomy from other OldFair point. To be precise, the topic is the *origin* of human bipedalism. But human bipedalism didn't originate in humans, but is derived from *hominoid* ancestors like australopiths or earlier.
A version of hominoid bipedalism eg. Homo, hylobatidA version of animal bipedalism eg. T.rex
A version of primate bipedalism eg. Sifaka
A version of mammal bipedalism eg. Kangaroo
A version of animal bipedalism eg. Hoatzin (adult)
If you want to expand the discussion beyond the origins of human bipedalism, then don't limit yourself to bipedalism; include all animal locomotion, up to and including invertebrates. Good luck with that.That is a good way to lose useful information relative to the topic, IMO. You've just erased hylobatids from the conversation. Just like Lieberman did in his endurance running H. erectus fantasy.
If you want to make coherent and relevant points about the origin of human bipedalism, then constrain your comments to Homo species and their likely ancestors.
Adult chimps have protruding muzzles and are mostly qpal on the ground. Adult humans have flat faces and are bipedal on the ground.
Your cited video shows an exceptional case among humans, which have >> relatively short arms and long legs, anatomically maladapted forHow is that an exceptional case among hominins? Only Usain Bolt can outrun qpal chimp at top speed.Imagine how much faster that person would be if he ran normally, likeAll Homo species are great apes by definition, including H.sapiens.Either way, the important point is the position and angle of foramen
magnum are diagnostic among all vertebrates for how they habitually
hold their head, and so includes/excludes bipedalism among hominids.
Yes, but no. Great apes are bipedal except when (hurrying) on open ground they adopt quadrupedalism. Homo retains the primitive bipedal gait of hominoid ancestors, as do hylobatids.
Yes, I meant 'arboreal great apes'. Humans are terrestrial great apes, hylobatids are arboreal lesser apes.
They do/did quadrupedalism only in exceptional cases.
https://youtu.be/pCrH6BOwxe4 15mph qpal running as a patas monkey, not a chimp.
this:
<https://www.youtube.com/watch?v=k3PZgbQ8auE>
quadrupedal locomotion.
Humans are faster qpal palm-down sprinter and qpal endurance runner than any other hominoid.
Patas monkey's arms are shorter than their legs: https://www.britannica.com/animal/patas-monkey
Locomotor Anatomy and Behavior of Patas Monkeys (Erythrocebus patas) with Comparison to Vervet Monkeys (Cercopithecus aethiops)
Adrienne L. Zihlman and Carol E. Underwood
Additional article information
Abstract
Patas monkeys (Erythrocebus patas) living in African savanna woodlands and grassland habitats have a locomotor system that allows them to run fast, presumably to avoid predators. Long fore- and hindlimbs, long foot bones, short toes, and a
adaptation that is the patas monkeys' basis for survival in grassland and savanna woodland areas.vervets give them access to highly dispersed, nutritious foods, water, and sleeping trees. Furthermore, patas monkeys have physiological adaptations that enable them to tolerate and dissipate heat. These features all contribute to the distinct
baboons climb trees, qpal running is just the short sprint to flight.Footraces between humans and patas monkeys are exceptional events.
Also, even though his head is in extreme
elevation, he can barely see where he's going, as his foramen magnum
is anatomically maladapted for quadrupedal motion. Silly Guinness >> records notwithstanding, any human moving quadrupedally from a
predator would soon become predator poop.
Why? Carrying a blade pirate-style teeth-clenched, with a few pards similarly equipped, would present predators with a serious challenge. Bipedally, better weapons could be carried, of course, but running itself isn't enough. Patas, vervet &
jerky. Predators attack from behind. There is no behind in a circle. But there is a vulnerable behind in an encircled predator. That is why the first knife slashes a rear hamstring/achilles/artery, while a pard is taunting up front, keeping the predator'Imagine yourself running quadrupedally with a blade pirate-style teeth clenched. Now imagine yourself running out of breath and exhausted as the predator you're running from catches up and eats you.Don't bring a fang to a knife fight. Don't run with scissors. But most importantly, don't get encircled, because then you're prey. My pards and I run out only far enough to encircle said predator, then sing kumbaya as we slash it into ribbons of
Fun is fun, but at least make your jokes relevant to the topic.
You continue to use above a non-standard meaning of bipedalism.That's not my understanding. My understanding is chimpanzees,Perhaps. My understanding is bipedal arboreal apes continued to walk... and wet aka tropical,and some of which are incidental, ex. molar patterns. DescendantCentral Africa is and was hot,
populations are more likely to share these features than are
independent populations. This suggests to me that a sufficiently
robust fossil record could answer this question with some degree of
certainty.
Alternately, my understanding is southern Europe and central Africa
are ecological opposites, in the sense that when one is hot and dry
the other is temperate and wet.
The adoption of qpal knucklewalking by African apes indicates that their ancient habitat went through a dry phase (rainforest became patchy) forcing a terrestrial dog-like gait.
bipedally on the ground, while non-bipedal arboreal apes also adopted
quadrupedal habits on the ground.
Bipedal walking is primitive in arboreal hominoids, quadrupedal walking is derived. I don't know of any 'non-bipedal arboreal apes', only monkeys.
gorillas, and orangutans are non-bipedal arboreal apes, meaning when
they are in the trees, they do not walk upright.
Their body orientation on and under branches is primarily upright, not pronograde with all limbs in compression aka quadrupedal. The modern AMHs orthogonal posture is derived, not the same as primitive upright bipedal arboreal hominoids.
Please direct me to "a standard meaning of bipedalism". Afaik, bipedalism is a trait of locomoting on 2 legs in compression, whether the hands are swinging, carrying or plucking.I acknowledge I am no authority to assert a standard meaning of *human* bipedalism. But I rely on the list of diagnostic features as described by Erika's aka Gutsick Gibbon's, who is at least one authority. From the video you cited previously:
Sloths are quadrumanual, orangs are also called that when hanging tensionally from four limbs, but bipedal when walking on thick branches.
<https://youtu.be/jo2ZLnucuHY>
1. Foramen magnum and occipital condyles positioned anterior and angled vertically.
2. Vertebrate lumbar lordosis.
3. Bowl-shaped pelvis with sagittally oriented iliia and anterior iliac spine.
4. Broad sacrum.
5. Thick cortical bone around femur neck.
6. Flattened elliptical distal condyles.
7. Opterator externus groove.
8. Valgus knee.
9. Three arches of foot's sole.
Also, I note that Erika expressed the same criticism I did about your quadrupedal human, that the foramen magnum precludes such habitual behavior.Rather obvious that. Yet we can do it, quickly when we have to. Our body form is closer to monkeys than to apes in some ways.
A list of features does not a meaning make.
Please direct me to "a standard meaning of bipedalism". You demanded it, I requested it.
Because there are some octopi that notoriously walk bipedally, they don't have any of those features.
BUT THEY DO WALK ON TWO LIMBS IN COMPRESSION. And **THAT** is the standard meaning of bipedalism.
So you must incorporate that into your description of human bipedalism. And so should Erika.
Hanging from branches using combinations of limbs isn't bipedalism any
more than is climbing up coconut palms.
Songbirds? If you meant hominoids only, they are all tropical. Miocene apes had warm/cool seasons, they did migrate.Suspension itself is not bipedalism.That's what I said.
I am unaware of any arboreal species which seasonally migrate.They weren't sessile, but very mobile.I suppose Miocene apes collected frequent-flier miles.As were most
arboreal apes prior to Australopithecines.
<https://www.britannica.com/place/Black-Sea/Climate>Again perhaps. It also suggests small bipedal arboreal apes werejust right for the evolution of small bipedal arboreal apes.
The fact that there are no small bipedal arboreal apes in Africa indicates that there was some climate shifting.
outcompeted.
They were, by monkeys which were more ground adapted, able to swiftly run between forest stands during a drier climate phase.
The relative position of the Black Sea didn't change from then to now.the southern Black Sea is between temperate and tropical.Correct. Southern Europe and the Black Sea are at the same latitudes.
This suggests they would tend to have the same climate. However, the
Black Sea is farther inland, and so suffers more continental extremes.
So any climate changes will appear first around the Black Sea and
become more extreme compared to southern Europe.
I'm talking about from 11ma through the MSC to 5ma. The Medit. & Red Seas dried out, the Black Sea didn't.
The important point is its position is deep in Eurasia, where >> >> >> continental climates rule.
It lies between the Atlantic-Mediterranean and the Caspian Sea, in the Peri-Tethyan basin, protected by the high Iranian plateau to the south. Not a typical continental climate.
**********************************
The climate of the landlocked Black Sea can be characterized generally
as continental (i.e., subject to pronounced seasonal temperature >> >> variations), although climatic conditions in some parts of the basin
are controlled to a great extent by the shoreline relief. A steppe
climate, with cold winters and hot, dry summers, is found in the >> >> northwestern part of the basin exposed to the influence of air masses
from the north.
************************************
Summer in north including Bavaria via Danube valley, winter in south including visits further southwardly.
To the
best of my knowledge, although they may have a large home range, they stick to one area throughout the year. This would suggest migrating Miocene arboreal apes are a unique exception. Do you know of any extant arboreal animals which seasonally migrate?Songbirds? Which 'arboreal animals' do you mean, hominoids only?
Sounds like a segue for aquatic ape hypothesis.I acknowledge that rift was one plausible pathway from Europe to >> >> Africa. The Red Sea was not, nor did it block such a pathway.My understanding is the Mediterranean dried out only about 6mya, long
after European, and presumably Black Sea, arboreal apes went extinct.
No, Danuvius and later Miocene apes there were of one lineage IMO, that may have lived there until 5ma, with successive expansional waves emigrating outwardly including towards Africa.
The Red Sea is too far south to affect migration from Europe to Africa
regardless of climate patterns.
It is part of the African-Anatolian rift.
I include it provisionally, more data needed.
Most proponents of that hypothesis tend to refuse to acknowledge that all extant (and by extension, archaic) Homo sleep well sheltered (dry, warm, shielded) from the elements (or try to be). Thus it is unrealistic imo.
Of course, I refer to the surrounding region, which today is hyper-arid
sapiens oldest known cooking (fish .78ma) and earliest waternut gathering and bread making. The region is amenable to hominins & Homo.To inform that I was stopping until i could get wifi again.Ok, stop as in "be right back". But this isn't a real-time chat. What's the point of mentioning it?Another stop.No, I am speaking of climate then *and* now. Regions around 30Moving toward 30 degrees latitude, rainfall becomes seasonally dry,
and then almost continuously dry. My understanding is, the only
native forests south of the Caspian are in the mountains, and adjacent
to the Mediterranean coasts. Arboreal apes of any kind would find
these deserts impassible.
You are speaking of recent climate. There are no arboreal apes there now.
degrees latitude tend to be drier than those around the equator, with
exceptions due to terrain and ocean currents.
Stop temporarily.
Unclear. Do you mean stop migration temporarily? If so, keep in mind
that the same climate changes which would create arid conditions
around 30 degrees latitude would also shrink forests further north and
south.
You appear to be claiming that the European Miocene apes could never have been linked to African and Asian apes. Yet they certainly were, else they wouldn't have existed at all.Such an "appearance" is incorrect. In certain cases, regions around
30 degrees latitude have/had enough rainfall to support forests. The
relevant point here is, global climate since the Miocene has gotten
colder and drier, especially around 30 degrees latitude, which has led
to the creation of large areas of treeless savannah and desert. I
don't know when European and African forests separated. Do you? >> >>
Also, the question isn't about the origin of apes generally. It's
about the origin of arboreal bipedal apes. We know they existed in
Pliocene Africa. They *may* have existed in Miocene Europe. Even if
they did, the two populations may still have evolved independently.
To a first approximation, average rainfall and temperature are
functions of latitude. However, while temperature is a function of
the sine of latitude, rainfall is more complex. It tends to be
continuously heavy near the equator, continuously dry near 30 degrees,
and seasonally variable between 30 and 60 degrees. This general
pattern is modified, sometimes dramatically, by terrain, ocean
currents, seasons, and Milankovitch cycles.
The most significant variable is Africa's northward tectonic
migration, about a centimeter a year since before the Miocene. So,
while central Africa has moved from south to north of the equator with
little effect, north Africa has approached and then went north of 30
degrees, making it over time ever drier, amplifying other climate
trends, making once wooded areas into vast savannah and desert.
Yes.
Also, Africa's tectonic slide north almost certainly pinched closed
the Gilbraltar Sttraits, which caused the Mediterranean to dry up at
least once, and likely several times as sea levels rose and fell. The
resulting hot salt basin would also have been impassible for arboreal
apes.
This is as true now as it was in theI would not claim nor disclaim that. The Levant is near the midpoint, extends the African Rift valley to Anatolia, is a major avian migration route between Africa and Eurasia, has fossil/artifacts of Homo erectus, neanderthal &
Miocene. This suggests to me there could not have been an unbroken
forested path for arboreal apes to migrate between Europe/Near East
and Central Africa.
lumbar vertebrae. This may have caused lordosis (the normal curvature of the human spine) and moved the center of mass over the hips and legs, which implies some habitual bipedal activity.https://en.wikipedia.org/wiki/Judaean_MountainsThe regions you describe above are part of the Mediterranean coastalI acknowledge the facts you describe above. However, the Levant is
savannah and desert except for a narrow strip along the Mediterranean
and up in the mountains. While this is no problem for terrestrial
bipeds like Homo, ISTM arboreal hominids like D.guggenmosi would have
a much harder time living/migrating there.
"is".
Again, refer to microclimate of Levant 11ma - 5ma. Today's Dead Sea was once the vast brackish Lake Lisan that reached to Lebanon, a gallery forest may have reached from Anatolia to Egypt.
mountains I mentioned previously.
The Dead Sea is by no means a coastal mountain region.
These are part of a series of ranges all along the eastern
Mediterranean coast.
... which runs parallel to the Mediterranean coast.I agree a coastal Mediterranean
forest is plausible.
I'm referring to the tectonic rift valley between Zimbabwe/Zambia and Lebanon/Anatolia.
Of course, there were coastal forests as well, but they were affected by the MSC.Cite the data you think is sufficient to answer this question. >> >> >> >What is ISTM?
However, my understanding is the evidence is
insufficient to say if it would have been as extensive and continuous
as you suggest during the time you suggest.
Haven't got enough hard data yet.
It's shorthand acronym for "It Seems To Me"
Ok, thanks.
Danuvius, Rudapithecus, Graecopithecus, Oranopithecus each had a unique trait shared with hominins. I think of them as a superspecies with local variations.-
If you place Danuvius half-way between fast brachiating bipedal long backed long achilles tendon hylobatids and bipedal Homo with long back and long achilles tendon, it fits perfectly.
Wiki:
Danuvius is thought to have had a broad chest. It is the first recorded Miocene great ape to have had the diaphragm located in the lower chest cavity, as in Homo, indicating an extended lower back and a greater number of functional
limited ankle loading, and the ankle would have had a hinge-like function, being most stable if positioned perpendicularly to the leg as opposed to at an angle in apes. Danuvius was likely able to achieve a strong grip with its big toes, unlike modern
The robust finger and hypertrophied wrist and elbow bones indicate a strong grip and load bearing adaptations for the arms. The legs also show adaptations for load-bearing, especially at the hypertrophied knee joint. There was likely
----
Q: Alex, what is Sifaka?
The Origins of Bipedal Locomotion
William EH Harcourt-Smith 2013
Handbook of PA doi 10.1007/978-3-642-27800-6_48-3
Abstract
The Origins of Bipedal Locomotionbipedal, but the degree to which they were bipedal remains the subject of considerable debate. The significant discoveries of fossil hominin remains in the last 40 years have resulted in this debate becoming increasingly focused on how bipedal certain
William EH Harcourt-Smith 2013
Handbook of PA doi 10.1007/978-3-642-27800-6_48-3
Abstract
Bipedalism is a highly specialized and unusual form of primate locomotion that is found today only in modern humans. [DD: Sifaka, Hylobatidea, All known Homo spp.] The majority of extinct taxa within the Hominini [DD: Hominoidea] were [DD: arboreal]
Op dinsdag 22 november 2022 om 17:38:01 UTC+1 schreef Daud Deden:
The Origins of Bipedal Locomotion
William EH Harcourt-Smith 2013
Handbook of PA doi 10.1007/978-3-642-27800-6_48-3
Abstract
Bipedalism is a highly specialized and unusual form of primate locomotion that is found today only in modern humans. [DD: Sifaka, Hylobatidea, All known Homo spp.]
The majority of extinct taxa within the Hominini [DD: Hominoidea] were [DD: arboreal] bipedal,
taxa were, rather than on the overall process. Although the early hominin fossil record remains poor, evidence points to at least two distinct adaptive shifts. First, there was a shift to habitual [DD: arboreal] bipedalism,but the degree to which they were bipedal remains the subject of considerable debate. The significant discoveries of fossil hominin remains in the last 40 years have resulted in this debate becoming increasingly focused on how bipedal certain fossil
shift was to fully obligate bipedalism [DD: Sifaka, Hylobatidae, Homo are all obligate bipeds.] and coincides with the emergence of the genus Homo [DD: No, of course not.].as typified by certain members of Australopithecus, but possibly including earlier genera such as Ardipithecus and Orrorin. Such taxa were [DD: arboreal] bipedal, but also retained a number of significant adaptations to arboreal climbing. The second
By the Early Pleistocene, certain members of Homo had acquired a postcranial skeleton indicating fully humanlike striding bipedalism [DD: No chin so they must have had a different striding gait & weight distribution than modern humans].
The final part of this chapter reviews why bipedalism was selected for. [DD: Bipedalism long preceded the advent of Homo sapiens.]
efficient procurement of food. [DD: Such as better access to arboreal fruits and nuts]There have been many theoretical explanations, and the most robust remain those linked to the emergence of more varied habitats. Such an environmental shift would have involved strong selection for new behavioral strategies most likely linked to the
I mostly agree with DD, but IMO we should specify: early-hominoid BPism was less walking-climbing BPism than wading-climbing BPism: Miocene Hominoidea lived in swamp forests (most likely in coastal forests in S-Eurasia along the Tethys Ocean),
where they frequently waded bipedally (upright) in the shallow water between the trees, and often climbed arms overhead in the branches above the water. This explains best in apes:
-complete tail loss,
-very broad sternum, thorax & pelvis + dorsal scapulas (also lateral movements of arms & legs),
-centrally placed lumbar spine, with 5 rather than 7 lumbar vertebras, etc.
This locomotion has been called (google) "aquarboreal" (aqua=water, arbor=tree).
Thank you for reviving this thread, Marc. I hope you are still monitoring it,
because I have a lot of comments to make on what Daud wrote, and on some that you added,
and I'm curious to see what you think about them.
You might not know that Daud announced here in s.b.p. about two
months ago that he was taking a vacation from here and also from sci.anthropology.paleo.
So don't expect any responses from him any time soon.
The Origins of Bipedal Locomotion
William EH Harcourt-Smith 2013
Handbook of PA doi 10.1007/978-3-642-27800-6_48-3
Bipedalism is a highly specialized and unusual form of primate locomotion that is found today only in modern humans. [DD: Sifaka, Hylobatidea, All known Homo spp.]
This was a very valid correction by Daud. I don't know whether he includes Indris or Avahis
under "Sifaka", but they too are bipedal. There may be something about Madagascar, where
all 3 of these other primates originated, that encourages bipedal locomotion.
The majority of extinct taxa within the Hominini [DD: Hominoidea] were [DD: arboreal] bipedal,
Here, OTOH, Daud was introducing a separate theme and not necessarily disagreeing.
Do you see it that way too, Marc?
fossil taxa were, rather than on the overall process. Although the early hominin fossil record remains poor, evidence points to at least 2 distinct adaptive shifts. First, there was a shift to habitual [DD: arboreal] bipedalism,but the degree to which they were bipedal remains the subject of considerable debate. The significant discoveries of fossil hominin remains in the last 40 years have resulted in this debate becoming increasingly focused on how bipedal certain
Here, too, Daud was not necessarily disagreeing; here, though, he was adding details
to the locomotion method rather than expanding the range of taxa.
second shift was to fully obligate bipedalism [DD: Sifaka, Hylobatidae, Homo are all obligate bipeds.] and coincides with the emergence of the genus Homo [DD: No, of course not.].as typified by certain members of Australopithecus, but possibly including earlier genera such as Ardipithecus and Orrorin. Such taxa were [DD: arboreal] bipedal, but also retained a number of significant adaptations to arboreal climbing. The
I'm not sure, but I think the author, William EH Harcourt-Smith, was only interested in the lineage
leading up to Homo, and may have thought that bipedalism was independently acquired by
Hylobatidae, as it seems to in the case of the lemurs mentioned above. Or he may have thought
that bipedalism was temporarily lost in our lineage, and then regained.
By the Early Pleistocene, certain members of Homo had acquired a postcranial skeleton indicating fully humanlike striding bipedalism [DD: No chin so they must have had a different striding gait & weight distribution than modern humans].
I do not see how the word "must" is justified by "No chin." Do you, Marc?
the efficient procurement of food. [DD: Such as better access to arboreal fruits and nuts]The final part of this chapter reviews why bipedalism was selected for. [DD: Bipedalism long preceded the advent of Homo sapiens.]> See above about "lineage."
There have been many theoretical explanations, and the most robust remain those linked to the emergence of more varied habitats. Such an environmental shift would have involved strong selection for new behavioral strategies most likely linked to
Here is where you came in, Marc:early-hominoid BPism was less walking-climbing BPism than wading-climbing BPism?
I mostly agree with DD, but IMO we should specify:
I've known about your wading-climbing hypothesis for over a year now, Marc, but
I don't recall anything about the location. In fact, I just had Africa in the back of my
mind when I read what you and Daud and Mario had written about it.
early-Pleist. predom.diving H.erectus
mid-Pleist. diving+wading (e.g. H.neand. seasonally along rivers following salmon??)
late-Pleist. wading-walking H.sapiens?
It's an interesting amplification: is it possible that our lineage goes back to SE Asia before
moving to Africa? or should I say, back to Africa? [Recall Proconsul and Ekembo, 17 to 20 mya,
predating Ramapithecus/Sivapithecus by about 5my.]
where they frequently waded bipedally (upright) in the shallow water between the trees, and often climbed arms overhead in the branches above the water. This explains best in apes:
-complete tail loss,
-very broad sternum, thorax & pelvis + dorsal scapulas (also lateral movements of arms & legs),
-centrally placed lumbar spine, with 5 rather than 7 lumbar vertebras, etc.
Could you explain the connections? none of these suggests "aquarboreal" to me.
This locomotion has been called (google) "aquarboreal" (aqua=water, arbor=tree).
By you, yes, but here is what a search in google led to: https://groups.io/g/AAT/message/70711
Jack, whoever he is, has trouble with the connections there. And your answers to him don't explain them.
Peter Nyikos Professor, Dept. of Mathematics
Univ. of South Carolina -- standard disclaimer-- http://people.math.sc.edu/nyikos
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