from Francesca Mansfield (thanks! :-)):

H. habilis was very probably aquarboreal (one of the Olduvai Hominins (OH 8) had its foot bitten off by a croc, although that doesn't prove anything except that it was by water when it got its foot bitten off). Take a look at Wikipedia:

"H. habilis may have been at least partially arboreal like what is postulated for australopithecines."
"The arms of H. habilis and australopithecines have generally been considered to have been proportionally long and so adapted for climbing and swinging.[32][33][34] "
"The humerus of OH 62 measured 258–270 mm (10.2–10.6 in) long and the ulna (forearm) 245–255 mm (9.6–10.0 in), which is closer to the proportion seen in chimpanzees. The hand bones of OH 7 suggest precision gripping, important in dexterity, as
well as adaptations for climbing."
"The thickness of the limb bones in OH 62 is more similar to chimpanzees than H. ergaster / H. erectus and modern humans, which may indicate different load bearing capabilities more suitable for arboreality in H. habilis.[35] The strong fibula of OH 35 (
though this may belong to P. boisei) is more like that of non-human apes, and consistent with arboreality and vertical climbing.[36]"
"In regard to the femur, traditionally comparisons with the A. afarensis specimen AL 288-1 have been used to reconstruct stout legs for H. habilis,"
"OH 8, a foot, is better suited for terrestrial movement than the foot of A. afarensis, though it still retains many apelike features consistent with climbing.[15] However, the foot has projected toe bone and compacted mid-foot joint structures, which
restrict rotation between the foot and ankle as well as at the front foot. Foot stability enhances the efficiency of force transfer between the leg and the foot and vice versa, and is implicated in the plantar arch elastic spring mechanism which
generates energy while running (but not walking)."

The thicker limb bones (than Lucy) and the compacted mid-foot structures suggest to me that H. habilis was no runner, but waded and perhaps swam frequently, while still maintaining upper body proportions for climbing and suspension in trees. Therefore,
aquarboareal, probably closer to chimpanzees.

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littor...@gmail.com wrote:

from Francesca Mansfield (thanks! :-)):

H. habilis was very probably aquarboreal (one of the Olduvai Hominins (OH 8) had its foot bitten off by a croc, although that doesn't prove anything except that it was by water when it got its foot bitten off). Take a look at Wikipedia:

I'll tell you, I don't like this Aquarboreal thing. I'm very uncomfortable with it. And
I'll tell you why.

Whether a species is "Aquarboreal" as you posit, or is in line with my model where
groups branched off from the Waterside mother population, pushed inland (probably following freshwater sources into the interior), only to adapt and/or interbreed with earlier groups to have done so, the observations are exactly the
same.

NO MATTER WHAT THOUGH...

Ardi, Lucy & habilis are all descended from a waterside ancestor.

They all descend from a bipedal, waterside ancestor.

AND THERE WAS INTERBREEDING!

For generations the status quo insisted that there was never any such thing as interbreeding, but it would have been going on from the start.

This is why I've often argued Bottlenecks, events (developments) that put the breaks on interbreeding. One such Bottleneck would have been Yellowstone, almost 9 million years ago.That would have HEAVILY favored bipedal waterside groups. And it would have de-selected the northern hemisphere.

This is also why I was so taken in by your notes on erectus. It seems to me that
erectus was the first modern man -- archaic type "modern" -- and was itself a Bottleneck.

A biological Bottleneck.

Most sources place the chromosome fusion event in alignment with erectus,
while other sources date the modern brain and even the loss of the baculum
to erectus. This would have allowed humans to have evolved without any influence from earlier, "Less derived" populations. But...

But the exact same process would continue. Groups would still peel off from
the mother waterside population, push inland and adapt. The only difference would be biological barriers to interbreeding with earlier populations.

Erectus would have been something of a "Reset Button." The Waterside
population could now only interbreed with groups that had peeled off,
pushed inland & adapted SINCE erectus evolved.

"H. habilis may have been at least partially arboreal like what is postulated for australopithecines."

Both would have been descended from a waterside population. Their
"Aquatic" adaptation were likely vestiges.




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Op donderdag 25 mei 2023 om 03:45:46 UTC+2 schreef JTEM is so reasonable:

littor...@gmail.com wrote:

from Francesca Mansfield (thanks! :-)):
H.habilis was very probably aquarboreal (one of the Olduvai Hominins (OH 8) had its foot bitten off by a croc, although that doesn't prove anything except that it was by water when it got its foot bitten off). Take a look at Wikipedia:

I'll tell you, I don't like this Aquarboreal thing. I'm very uncomfortable with it. And
I'll tell you why.
Whether a species is "Aquarboreal" as you posit, or is in line with my model where
groups branched off from the Waterside mother population, pushed inland (probably following freshwater sources into the interior), only to adapt and/or
interbreed with earlier groups to have done so, the observations are exactly the
same.
NO MATTER WHAT THOUGH...
Ardi, Lucy & habilis are all descended from a waterside ancestor.
They all descend from a bipedal, waterside ancestor.

Yes, all Hominoidea had bipedal+waterside=aquarboreal ancestors.
Lucy was IMO obviously a fossil relative of Gorilla, see my Hum.Evol.papers. Most so-called "habilis" were fossil Pan or Gorilla (I'm not sure).

AND THERE WAS INTERBREEDING!

between?
I don't understand this interbreeding "argument"...

For generations the status quo insisted that there was never any such thing as
interbreeding, but it would have been going on from the start.
This is why I've often argued Bottlenecks, events (developments) that put the breaks on interbreeding. One such Bottleneck would have been Yellowstone, almost 9 million years ago.That would have HEAVILY favored bipedal waterside groups. And it would have de-selected the northern hemisphere. > This is also why I was so taken in by your notes on erectus. It seems to me that
erectus was the first modern man -- archaic type "modern" -- and was itself a Bottleneck.

Well possible.
But H.erectus was NOT aquarboreal any more, of course:
early-Pleistocene Homo were frequent shallow divers, probably mostly for shellfish:
pachyosteosclerosis, island colonizations, platycephaly, brain enlargement (DHA), stone tools, shell engravings etc.

A biological Bottleneck.
Most sources place the chromosome fusion event in alignment with erectus, while other sources date the modern brain and even the loss of the baculum
to erectus. This would have allowed humans to have evolved without any influence from earlier, "Less derived" populations. But...
But the exact same process would continue. Groups would still peel off from the mother waterside population, push inland and adapt. The only difference would be biological barriers to interbreeding with earlier populations. Erectus would have been something of a "Reset Button." The Waterside population could now only interbreed with groups that had peeled off,
pushed inland & adapted SINCE erectus evolved.

"H.habilis may have been at least partially arboreal like what is postulated for australopithecines."

Yes, aquarboreal (aqua=water, arbor=tree): BP wading + climbing arms overhead in the branches above the water.
Google "australopith habilis verhaegen" or so:
"habilis" was a fossil relative of Pan or Gorilla, it has nothing to do with Homo, who was at S.Asian coasts then.

Both would have been descended from a waterside population. Their
"Aquatic" adaptation were likely vestiges.

Yes, Mio-Pliocene Hominoidea were still "waterside"=aquarboreal.
But we early-mid-Pleist.Homo had our own evolution, of course: shallow-diving.

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littor...@gmail.com wrote:

AND THERE WAS INTERBREEDING!

between?
I don't understand this interbreeding "argument"...

Bipedalism: Pick a date. Any date. Doesn't matter. This is just for the
sake of argument so let's say bipedalism arose 10 million years ago.

How did it arise? Aquatic Ape. Waterside. Littoral Ape.

So we have a population exploiting marine resources, this leads to
bipedalism. But then...

The more successful this waterside population, the larger it is. The
marine resources can support a larger population density -- all that
free protein -- so there's a lot of them. And some groups are peeling
off, pushing inland, following freshwater sources back into the
interior... transitional wetlands...

This happens for a variety of reasons. Could be conflicts. Could be
natural disasters. Could be in their normal consume-resource-then
-move-on the odd group turned right at the river outlet instead of
continuing along the shoreline...

So we have our Waterside population, we have bipedalism and we
have groups pushing inland. And when did this all start? Why, 10
million years ago!

Okay, so 8 million years ago the same thing is going on. We have
a bipedal waterside population, we have groups periodically pushing
inland and adapting only now they are 2 million years BETTER
adapted to the waterside environment. AND, those first groups to
push inland are now 2 million years worth of evolutionary adaptations
better suited to the inland environment. And they interbreed.

Again, this is all for the sake of argument. A 2 million year gap is
probably wildly exaggerated but you get the idea: Every time a
group peels off from the waterside population & pushes inland, they
encounter the descendants of the groups to have previously peeled
off and pushed inland. And they interbred. If they could.

This interbreeding is fact. It's what we later identify as "Regional Continuity," where new arrivals in places like Australia are injecting
their DNA into the population while the people/culture appear
fairly constant to us going by the archaeology.

So we need barriers to interbreeding. We need them. We have to
have barriers to interbreeding.

Without barriers to interbreeding, the inland group has as much
potential of influencing the evolutionary path of the waterside
group as the waterside group has for influencing the evolution of
the inland group. Maybe not at first, but as the inland group
succeeded, spread out -- GREW -- their genetic influence would
grow by sheer weight of numbers.

There were many natural barriers to interbreeding. The
Yellowstone eruption of some 8.7 million years ago would have
heavily stressed groups the furthest from the equator, especially
in the northern hemisphere, and of course would have placed
more stress on inland groups than waterside groups.

Stressed = "Killed lots of."

And death is probably the biggest barrier to interbreeding, as it
turns out.

Probably the most significant barrier to interbreeding though
was genetic. I'm guessing.

Look. I steal all these ideas from the rest of you so don't expect
me to be able to explain it all in great detail but, erectus seems
to be the dividing point. So much so that I would argue that
erectus /Was/ modern man. And archaic type modern but THE
first so called modern. Erectus aligns with the loss of the
baculum. Erectus aligns with the development of the modern
brain. And erectus aligns with the chromosome fusion, which
appears to have been a barrier to interbreeding.

Starting with erectus, the interbreeding with older Homo had
to stop, or at least was severely curtailed.

But, before erectus there wasn't a whole heck of a lot of GENETIC
or BIOLOGICAL barriers to interbreeding. So the last of Ardi had
to be interbreeding with australopithecus, and australopithecus
was likely interbreeding with habilis.

Everyone was interbreeding with everyone else, if they could.

This interbreeding never stops. Erectus put the breaks on
interbreeding with earlier Homo types, because of the
chromosome fusion, but the process of groups peeling off,
pushing inland & adapting never stopped. And interbreeding
with and between these new inland groups certainly happened.

This much is established fact.





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Op donderdag 25 mei 2023 om 19:19:45 UTC+2 schreef JTEM is so reasonable:

littor...@gmail.com wrote:

AND THERE WAS INTERBREEDING!

between? I don't understand this interbreeding "argument"...

Bipedalism: Pick a date. Any date. Doesn't matter. This is just for the
sake of argument so let's say bipedalism arose 10 million years ago.
How did it arise? Aquatic Ape. Waterside. Littoral Ape.
So we have a population exploiting marine resources, this leads to bipedalism. But then...

Did the marine resources lead to BPism??
IMO the coastal forest simply led to aquarborealism: wading+climbing upright. India approaching S-Eurasia formed island archipelagoes rich in coastal forests.
These early-Miocene Hominoidea were initially still mostly frugivorous?

Plate tectonics & hominoid splittings, IMO:
- India approaching S-Eursasia c 25 Ma = cercopith/ape split N/S Tethys Ocean, - India further underneath Eurasia c 20 = lesser/great ape split E/W Tethys Ocean,
- Mesopotamian Seaway closure c 15 Ma = pongid/hominid split E/W Med/Ind.ocean, - northern Rift fm c 8 Ma = Gorilla/HP split N-Rift/Red Sea,
- Red Sea opening into Gulf 5.3 Ma = Homo/Pan split S.Asia/E.Africa.

Why did H.erectus (only begin-Pleist.??) began more diving (vs non-Homo apes)? more shellfish? presence of pongids in SE.Asian coastal forests?? ...?

Of course, there was often interbreeding between coastal & riverside populations,
but why & how was this of special importance in our evolution??


_____

The more successful this waterside population, the larger it is. The
marine resources can support a larger population density -- all that
free protein -- so there's a lot of them. And some groups are peeling
off, pushing inland, following freshwater sources back into the
interior... transitional wetlands...
This happens for a variety of reasons. Could be conflicts. Could be
natural disasters. Could be in their normal consume-resource-then
-move-on the odd group turned right at the river outlet instead of
continuing along the shoreline...
So we have our Waterside population, we have bipedalism and we
have groups pushing inland. And when did this all start? Why, 10
million years ago!
Okay, so 8 million years ago the same thing is going on. We have
a bipedal waterside population, we have groups periodically pushing
inland and adapting only now they are 2 million years BETTER
adapted to the waterside environment. AND, those first groups to
push inland are now 2 million years worth of evolutionary adaptations
better suited to the inland environment. And they interbreed.
Again, this is all for the sake of argument. A 2 million year gap is
probably wildly exaggerated but you get the idea: Every time a
group peels off from the waterside population & pushes inland, they
encounter the descendants of the groups to have previously peeled
off and pushed inland. And they interbred. If they could.
This interbreeding is fact. It's what we later identify as "Regional Continuity," where new arrivals in places like Australia are injecting
their DNA into the population while the people/culture appear
fairly constant to us going by the archaeology.
So we need barriers to interbreeding. We need them. We have to
have barriers to interbreeding.
Without barriers to interbreeding, the inland group has as much
potential of influencing the evolutionary path of the waterside
group as the waterside group has for influencing the evolution of
the inland group. Maybe not at first, but as the inland group
succeeded, spread out -- GREW -- their genetic influence would
grow by sheer weight of numbers.
There were many natural barriers to interbreeding. The
Yellowstone eruption of some 8.7 million years ago would have
heavily stressed groups the furthest from the equator, especially
in the northern hemisphere, and of course would have placed
more stress on inland groups than waterside groups.
Stressed = "Killed lots of."
And death is probably the biggest barrier to interbreeding, as it
turns out.
Probably the most significant barrier to interbreeding though
was genetic. I'm guessing.
Look. I steal all these ideas from the rest of you so don't expect
me to be able to explain it all in great detail but, erectus seems
to be the dividing point. So much so that I would argue that
erectus /Was/ modern man. And archaic type modern but THE
first so called modern. Erectus aligns with the loss of the
baculum. Erectus aligns with the development of the modern
brain. And erectus aligns with the chromosome fusion, which
appears to have been a barrier to interbreeding.
Starting with erectus, the interbreeding with older Homo had
to stop, or at least was severely curtailed.
But, before erectus there wasn't a whole heck of a lot of GENETIC
or BIOLOGICAL barriers to interbreeding. So the last of Ardi had
to be interbreeding with australopithecus, and australopithecus
was likely interbreeding with habilis.
Everyone was interbreeding with everyone else, if they could.
This interbreeding never stops. Erectus put the breaks on
interbreeding with earlier Homo types, because of the
chromosome fusion, but the process of groups peeling off,
pushing inland & adapting never stopped. And interbreeding
with and between these new inland groups certainly happened.
This much is established fact.

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

littor...@gmail.com wrote:

Why did H.erectus (only begin-Pleist.??) began more diving (vs non-Homo apes)?

Because they were no longer genetically (evolutionarily) influenced by
older, more archaic inland groups. Thanks to the chromosome fusion
putting the breaks to interbreeding, they were exclusively waterside, at
least until the first of them broke off, pushed inland and adapted to the
new environment.

Of course, there was often interbreeding between coastal & riverside populations,
but why & how was this of special importance in our evolution??

Google: distributed computing

Evolution was in tandum. Each break away group represented a
node working on the evolutionary problem. When a beneficial
trait arose it could be shared across the network, via the coastal
population.

At some point this was bad, with inland, wannabe "Ape" groups
contributing to the coastal population's gene pool. But with the
Chromosome fusion, starting with erectus, this sharing of DNA
with older, more archaic types ceased. They couldn't interbreed
with inland groups until they themselves started peeling off,
pushing inland and adapting to their new environments... thanks
to the chromosome fusion.



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Op vrijdag 26 mei 2023 om 04:58:45 UTC+2 schreef JTEM is so reasonable:

littor...@gmail.com wrote:

Why did H.erectus (only begin-Pleist.??) began more diving (vs non-Homo apes)?

Because they were no longer genetically (evolutionarily) influenced by
older, more archaic inland groups.

Not unlikely: erectus had a quite different lifestyle & diet:
diving for shellfish (POS, CC+ etc.) vs wading-climbing.

Thanks to the chromosome fusion
putting the breaks to interbreeding,

Cause or consequence?

they were exclusively waterside, at
least until the first of them broke off, pushed inland and adapted to the
new environment.

Of course, there was often interbreeding between coastal & riverside populations,
but why & how was this of special importance in our evolution??

Google: distributed computing
Evolution was in tandem. Each break away group represented a
node working on the evolutionary problem. When a beneficial
trait arose it could be shared across the network, via the coastal population.
At some point this was bad, with inland, wannabe "Ape" groups
contributing to the coastal population's gene pool. But with the
Chromosome fusion, starting with erectus, this sharing of DNA
with older, more archaic types ceased. They couldn't interbreed
with inland groups until they themselves started peeling off,
pushing inland and adapting to their new environments... thanks
to the chromosome fusion. 64

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littor...@gmail.com wrote:

Thanks to the chromosome fusion
putting the breaks to interbreeding,

Cause or consequence?

I imagine that the Chromosome Fusion event is what caused the clean
break from more archaic types. But, there's no way to know for absolute
sure from our perspective.

At some point all the different groups (populations) had to start looking
and acting so different from each other that interbreeding could be no
more than a rarity. Even today some of what we think of as "Primitive"
cultures have complex marriage rules.

Culturally, look at Bonobo vs Chimpanzee.

So there were speed bumps to interbreeding cropping up all along the
way -- everything from geographical (distance) to cultural and even just
plain looks. If you don't recognize something as a potential mate then...

Dinner?




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