Bear with me...

If Lucy's ilk are "Established" as bipedal, from the Laetoli footprints,
and Sahelanthropus tchadensis appears MORE (not less) adapted to
bipedalism in important ways, then we're already pushing the origins
to bipedalism back more than 7+ million years ago.

I might even argue that Sahelanthropus tchadensis, being closer to
the origins of bipedalism, would have had less time, opportunity
(reason) to evolve back away from it than some later species..

I said I might. I might. I might not but, yeah, I might.

(You never know with me)

So, when did bipedalism arise? Throwing out guesses here... 8.7
million years ago. Which should come as no surprise, come to
think about it, because I put that in the subject line... damn. Gave
it all away. No "Big Reveal."

Why then? Because Yellowstone erupted and it was earth
shattering.

Check Wiki on the timing:

https://en.wikipedia.org/wiki/Tortonian

It was a global catastrophe. It was, in any and every real
sense, the kind of "Sink or swim" event where populations had
to evolve or die -- "Publish or Perish." And that's the sort of thing
which is going to heavily favor populations that both live
towards the equator AND live along the ocean. Not inland, the
coast.

When you have a super volcanic eruption on that scale you...

#1. Don't want to be in the northern hemisphere. That's who is
always going to take the brunt of it, recover last.

Take my word on it. I only know about 90^347 times as much
about "Climate" as the average Extinction Rebellion or Greta
acolyte so, clearly I'm no expert. don't expect me to explain it to
you. Suffice it to say that the whole world is screwed by events
on this scale, the northern hemisphere doubly so. Find someone
smarter to work out the details.

#2. You want to be as close to the equator as you can, because
when the Volcanic Winter hits you want as much breathing
room as you can muster.

#3. You want to be on the coast. The ocean moderates the climate.
The coast is cooler in the summer because it takes a hell of a lot of
energy to warm up all that water. And it's warmer in the winter
because it's holding a lot of energy, releasing it.

#4. Seafood is orders of magnitude more stable than anything
you're going to find inland. A mega disaster strikes, vegetation
dies, all the animals dependent upon it dies... the predators
dependent upon them.

So Yellowstone explodes in a climate catastrophe. We're talking
a 15 or 30 on a scale of 1 to 10. And I'm not just saying that
because I'm bad at math. This was BIG! And that created a "Last
man left standing" situation for our ancestors. Anything inland
died. Anything NOT exploiting the sea already, or immediately
inclined to turn to the sea out of hunger, was pretty much
guaranteed to drop dead.

So that's my best guess for you: 8.7 million years.

Try to envision something like the crab-eating macaque. But,
as soon as Yellowstone detonated, roughly the size of Toba
about 74,000 years ago, all the NON crab-eating macaques
drop dead, and there's little or nothing outside of their
seafood for them to eat. That leaves a situation where 100%
of all the selective pressures -- EVOLUTION, BABY! -- is on
our Aquatic Ape.

Now erase "Monkeys" and put "Apes."

There. Case closed? Do I place the date too soon?


-- --

https://jtem.tumblr.com/post/707031415595925504

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* Origin: fsxNet Usenet Gateway (21:1/5)

Op zaterdag 21 januari 2023 om 08:00:57 UTC+1 schreef JTEM is my hero:

Bear with me...

8.7 Ma?? :-) Most likely >25 Ma: early Hominoidea were no doubt already frequently bipedal: wading vertically in swamp forests (probably coastal forests), climbing arms overhead in the branches above the swamps, as still seen sometimes in lowland
gorillas or bonobos wading for sedges or waterlilies, google e.g. "bonobo wading".
Google e.g.
- Mio-Pliocene hominoid (ape) evolution, google “aquarboreal”,
- Plio-Pleistocene Homo, google e.g. “human evolution Verhaegen”.

______

If Lucy's ilk are "Established" as bipedal, from the Laetoli footprints,
and Sahelanthropus tchadensis appears MORE (not less) adapted to
bipedalism in important ways, then we're already pushing the origins
to bipedalism back more than 7+ million years ago.

I might even argue that Sahelanthropus tchadensis, being closer to
the origins of bipedalism, would have had less time, opportunity
(reason) to evolve back away from it than some later species..

I said I might. I might. I might not but, yeah, I might.

(You never know with me)

So, when did bipedalism arise? Throwing out guesses here... 8.7
million years ago. Which should come as no surprise, come to
think about it, because I put that in the subject line... damn. Gave
it all away. No "Big Reveal."

Why then? Because Yellowstone erupted and it was earth
shattering.

Check Wiki on the timing:

https://en.wikipedia.org/wiki/Tortonian

It was a global catastrophe. It was, in any and every real
sense, the kind of "Sink or swim" event where populations had
to evolve or die -- "Publish or Perish." And that's the sort of thing
which is going to heavily favor populations that both live
towards the equator AND live along the ocean. Not inland, the
coast.

When you have a super volcanic eruption on that scale you...

#1. Don't want to be in the northern hemisphere. That's who is
always going to take the brunt of it, recover last.

Take my word on it. I only know about 90^347 times as much
about "Climate" as the average Extinction Rebellion or Greta
acolyte so, clearly I'm no expert. don't expect me to explain it to
you. Suffice it to say that the whole world is screwed by events
on this scale, the northern hemisphere doubly so. Find someone
smarter to work out the details.

#2. You want to be as close to the equator as you can, because
when the Volcanic Winter hits you want as much breathing
room as you can muster.

#3. You want to be on the coast. The ocean moderates the climate.
The coast is cooler in the summer because it takes a hell of a lot of
energy to warm up all that water. And it's warmer in the winter
because it's holding a lot of energy, releasing it.

#4. Seafood is orders of magnitude more stable than anything
you're going to find inland. A mega disaster strikes, vegetation
dies, all the animals dependent upon it dies... the predators
dependent upon them.

So Yellowstone explodes in a climate catastrophe. We're talking
a 15 or 30 on a scale of 1 to 10. And I'm not just saying that
because I'm bad at math. This was BIG! And that created a "Last
man left standing" situation for our ancestors. Anything inland
died. Anything NOT exploiting the sea already, or immediately
inclined to turn to the sea out of hunger, was pretty much
guaranteed to drop dead.

So that's my best guess for you: 8.7 million years.

Try to envision something like the crab-eating macaque. But,
as soon as Yellowstone detonated, roughly the size of Toba
about 74,000 years ago, all the NON crab-eating macaques
drop dead, and there's little or nothing outside of their
seafood for them to eat. That leaves a situation where 100%
of all the selective pressures -- EVOLUTION, BABY! -- is on
our Aquatic Ape.

Now erase "Monkeys" and put "Apes."

There. Case closed? Do I place the date too soon?

-- --

https://jtem.tumblr.com/post/707031415595925504

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

littor...@gmail.com wrote:

8.7 Ma?? :-) Most likely >25 Ma: early Hominoidea were no doubt already frequently bipedal: wading vertically
in swamp forests (probably coastal forests), climbing arms overhead in the branches above the swamps, as
still seen sometimes in lowland gorillas or bonobos wading for sedges or waterlilies, google e.g. "bonobo wading".

My ultimate point was that, absent an event like Yellowstone, there's just as much selective pressure -- evolution -- for all the other environments as there there is for the Waterside niche.

So you can have groups exploiting marine resources going back tens of millions of years, but without a cataclysm eliminating the inland contribution to the gene
pool, concentrating evolution on the adaption to aquatic resources, it's not really
"Aquatic Ape." It's an ape. It's just an ape.

THAT is the significance of Yellowstone 8.7 million years ago. It so disadvantaged
those populations which weren't on the coast, closer to the equator, that there weren't any left to breed with the waterside groups... or so few that they couldn't
moderate the evolution (adaptations).




-- --

https://jtem.tumblr.com/post/707302974280581120

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