The evolution of human bipedalism can only be understood in the light of the "aquarboreal theory": biological, comparative & other evidence suggests that early hominids frequently waded bipedally (with fully extended legs, Böhme cs 2019 Nature 575:489-493) in bais, mangrove or swamp forests etc., and also climbed arms overhead in the branches above the water (with fully extended arms, see Böhme ibid.), as still seen occasionally in bonobos wading for waterlilies, or lowland gorillas wading for sedges or other AHV (aquatic herbaceous vegetation), google e.g. illustrations "bonobo wading" or "gorilla bai". Miocene hominids such as Pierolapithecus, living along the Tethys Sea (Medit.Sea) & the Red Sea, followed the Rift, rivers, lakes or bais inland into E & later S.Africa, and evolved into australopiths (in parallel in E & S.Africa, from Pliocene "gracile" to Pleistocene "robust"?).

This aquarboreal lifestyle (Latin aqua=water, arbor=tree) best explains how Miocene hominids (e.g. Danuvius, Pierolapithecus) as well as Plio-Pleistocene australopiths moved (frequently grasping branches above the water, and wading with extended legs) and how human bipedalism evolved from this locomotion, see our TREE paper: google "Aquarboreal Ancestors".

littor...@gmail.com wrote:
> The evolution of human bipedalism can only be understood in the light of the "aquarboreal theory": biological, comparative & other evidence suggests that early hominids frequently waded bipedally (with fully extended legs, Böhme cs 2019 Nature 575:489-493) in bais, mangrove or swamp forests etc., and also climbed arms overhead in the branches above the water (with fully extended arms, see Böhme ibid.), as still seen occasionally in bonobos wading for waterlilies, or lowland gorillas wading for sedges or other AHV (aquatic herbaceous vegetation), google e.g. illustrations "bonobo wading" or "gorilla bai". Miocene hominids such as Pierolapithecus, living along the Tethys Sea (Medit.Sea) & the Red Sea, followed the Rift, rivers, lakes or bais inland into E & later S.Africa, and evolved into australopiths (in parallel in E & S.Africa, from Pliocene "gracile" to Pleistocene "robust"?).
>
> This aquarboreal lifestyle (Latin aqua=water, arbor=tree) best explains how Miocene hominids (e.g. Danuvius, Pierolapithecus) as well as Plio-Pleistocene australopiths moved (frequently grasping branches above the water, and wading with extended legs) and how human bipedalism evolved from this locomotion, see our TREE paper: google "Aquarboreal Ancestors".

This doesn't really explain HOW bipedalism was acquired. It simply states what it was used
for after it came about.

No, it's similar to the savanna nonsense in that the behavior made possible by the adaptation
had to precede it...

I do agree that A.A. best explains bipedalism. Just not this model.

Evolution relies on selective pressure and there is no better pressure than death: If you
can't manage, you die. So we're not looking for what would be beneficial but what would
be lethal. This much is screaming obvious once you realize the selection bias.

Imagine if you "Studied" lottery players by only ever looking at winners. It would be very
easy for someone to get the impression that to play the lottery is to win it. In reality,
almost everybody who plays loses. And the same is true for animals. When animals come
under distress, mostly they just die. And that's necessary. If short neck genes typify your
population, it's never enough for you and your long neck mutation to survive. Your DNA
will simply be swamped out by the short neck DNA. No, in addition to living you need the
short necks to die, or at least enough of them so that your mutation can propagate.

Anyway, the most likely catalyst here, in my ever so humble opinion, is migration.

You go somewhere, you consume all the resources and then you move on.

Under this model our ancestors are spreading everywhere, right? They're everywhere from
Africa to Asia. But it also means that they HAD TO move on at some point.

They consumed resources then they moved on, migrated. And with the resources gone,
NOT moving on meant death. And death is what drives evolution.

So they're exploiting aquatic resources then moving on... having to deal with low and
high tides... having to maybe cross channels... having to deal with storm surges and
flooding...

NOT dealing with these things means death. It means that the only ones left standing,
in more ways than one, are the ancestors that could deal with the water. And a really
easy way to do that is to simply stand up, increasing the depth of the water they could
successfully deal with.

So migration.

Why'd they migrate? That's the next question, but we know that they did.

Maybe breeding "Strategy?" Maybe the natural checks & balances vanished or at least
greatly diminished?

Or maybe it just didn't matter anymore, population size. Maybe it was a case that once
they started migrating there was no need to keep populations in check. After all, what
difference did it really make if they moved on after a week or only five days?

So migration could have caused the elimination to population checks or it could have
been caused by it. But they do fit together.

-- --

https://jtem.tumblr.com/post/663996512177651712

Op maandag 4 oktober 2021 om 03:01:16 UTC+2 schreef I Envy JTEM:

> > The evolution of human bipedalism can only be understood in the light of the "aquarboreal theory": biological, comparative & other evidence suggests that early hominids frequently waded bipedally (with fully extended legs, Böhme cs 2019 Nature 575:489-493) in bais, mangrove or swamp forests etc., and also climbed arms overhead in the branches above the water (with fully extended arms, see Böhme ibid.), as still seen occasionally in bonobos wading for waterlilies, or lowland gorillas wading for sedges or other AHV (aquatic herbaceous vegetation), google e.g. illustrations "bonobo wading" or "gorilla bai". Miocene hominids such as Pierolapithecus, living along the Tethys Sea (Medit.Sea) & the Red Sea, followed the Rift, rivers, lakes or bais inland into E & later S.Africa, and evolved into australopiths (in parallel in E & S.Africa, from Pliocene "gracile" to Pleistocene "robust"?).
> > This aquarboreal lifestyle (Latin aqua=water, arbor=tree) best explains how Miocene hominids (e.g. Danuvius, Pierolapithecus) as well as Plio-Pleistocene australopiths moved (frequently grasping branches above the water, and wading with extended legs) and how human bipedalism evolved from this locomotion, see our TREE paper: google "Aquarboreal Ancestors".

> This doesn't really explain HOW bipedalism was acquired. It simply states what it was used
> for after it came about.

It does: Nasalis also wades upright & surface-swims sometimes, got larger, reduced its tail etc. Swamp/bai/mangrove-dwelling aquarborealism (vertical wading-climbing) best explains why Miocene apes became different from monkeys after the OWM/ape split: larger size (gibbons still have gestations periods "too long" for their size), tail loss, centrally-placed spine (instead of dorsally as in monkeys), very broad pelvis & thorax + wide sternuma & dorsal scapulas (allowing lateral movements of arms & legs), stretched legs (vs indri's hopping), very long arms etc.: they apparently climbed arms overhead & waded bipedally with extended legs in swamp forests. Did they also frequently (surface)swim, e.g. to reach islands or other mangrove forests? This also explains why they migrated along Tethys Ocean coasts: first hylobatids East, long thereafter (Mesopotamian Seaway closure c 15 Ma?) hominids West along the Med.Sea, pongids East (forcing hylobatids higher into the tree). Some late-Miocene hominids coming from the Med migrated to the Red Sea coasts, where they split c 8 Ma into Gorilla (inland along the Rift ->Paranthropus afarensis etc.) & HP in the Gulf or so, and c 5 Ma into Pan along the E.Afr.coasts (->Australop.africanus etc.) & Homo initially still in the Red Sea & then along the S.Asian coasts as far as Java & SE.Asian islands early-Pleistocene: they evolved from aquarboreal to wading-shallow-diving + began using stones to open shellfish, rich in DHA cf brain-enlargement, pachyosteosclerosis etc. Late-Pleistocene Homo evolved from wading to walking, but we are still ill-adapted to running: flat feet + very long 1st & 5th digital rays, very unlike cursorial ostriches or kangaroos or quadrupeds.

_____

> No, it's similar to the savanna nonsense in that the behavior made possible by the adaptation
> had to precede it...
>
> I do agree that A.A. best explains bipedalism. Just not this model.
>
> Evolution relies on selective pressure and there is no better pressure than death: If you
> can't manage, you die. So we're not looking for what would be beneficial but what would
> be lethal. This much is screaming obvious once you realize the selection bias.
>
> Imagine if you "Studied" lottery players by only ever looking at winners. It would be very
> easy for someone to get the impression that to play the lottery is to win it. In reality,
> almost everybody who plays loses. And the same is true for animals. When animals come
> under distress, mostly they just die. And that's necessary. If short neck genes typify your
> population, it's never enough for you and your long neck mutation to survive. Your DNA
> will simply be swamped out by the short neck DNA. No, in addition to living you need the
> short necks to die, or at least enough of them so that your mutation can propagate.
>
> Anyway, the most likely catalyst here, in my ever so humble opinion, is migration.
>
> You go somewhere, you consume all the resources and then you move on.
>
> Under this model our ancestors are spreading everywhere, right? They're everywhere from
> Africa to Asia. But it also means that they HAD TO move on at some point.
>
> They consumed resources then they moved on, migrated. And with the resources gone,
> NOT moving on meant death. And death is what drives evolution.
>
> So they're exploiting aquatic resources then moving on... having to deal with low and
> high tides... having to maybe cross channels... having to deal with storm surges and
> flooding...
>
> NOT dealing with these things means death. It means that the only ones left standing,
> in more ways than one, are the ancestors that could deal with the water. And a really
> easy way to do that is to simply stand up, increasing the depth of the water they could
> successfully deal with.
>
> So migration.
>
> Why'd they migrate? That's the next question, but we know that they did.
>
> Maybe breeding "Strategy?" Maybe the natural checks & balances vanished or at least
> greatly diminished?
>
> Or maybe it just didn't matter anymore, population size. Maybe it was a case that once
> they started migrating there was no need to keep populations in check. After all, what
> difference did it really make if they moved on after a week or only five days?
>
> So migration could have caused the elimination to population checks or it could have
> been caused by it. But they do fit together.
> -- --
>
> https://jtem.tumblr.com/post/663996512177651712

littor...@gmail.com wrote:

> It does: Nasalis also wades upright & surface-swims sometimes, got larger, reduced its tail etc.

That's logic, not evolution, and it's as backwards as savannah "endurance running" where the
behavior precedes the adaptations.

We know it can't work that way because if adaptations cropped up they'd be immediately
swamped by the rest of the gene pool & bred out of existence. You need a mechanism to
STOP those without the mutation from breeding.

That's how evolution works.

-- --

https://jtem.tumblr.com/post/664349103659139073

Op donderdag 7 oktober 2021 om 23:32:25 UTC+2 schreef I Envy JTEM:

> > It does: Nasalis also wades upright & surface-swims sometimes, got larger, reduced its tail etc.

> That's logic, not evolution,

That's comparative data.

littor...@gmail.com wrote:

> That's comparative data.

The problem with evolution is that we look at the results and then
work backwards. For this reason we see what happened as more
of a foregone conclusion rather than one single potential result out
of many. So instead of looking at HOW things ended up we must
look elsewhere.

Evolution is a change, we say "Mutation." Genes "Mutate" and that
mutation propagates. But because we're talking maybe as few as
a single individual initially carrying that mutation -- maybe a litter
but quite possibly only one individual -- the mutation is never going
to compete. It's going to be breeding with members of the
population without the mutation, and most likely their offspring will
the breeding with members without the mutation...

So we need a mechanism to STOP that from happening. We need
a mechanism to STOP the members without the mutation from
out breeding, swamping the mutation. And that's usually death.

Something has to kill off the members without it.

Alternatively: The Founder Effect. As few as a single (pregnant)
individual can become isolated, become a breeding population
onto itself.

Anyway, back to death...

The most likely cause of death -- speaking ultimately -- and why it was
our ancestors and not all these others, is migration. They're living off
the water, seafood, consuming resources and moving on. This supports
a much larger population density than terrestrial foraging, allowing more
opportunity for mutations to crop up, but it also means that they're
encountering differing water depths. They're crossing channels. They're
wading out further...

What was killing them was the water.

So any mutation that made the water more survivable would have been
a great benefit, while at the same time the lack of that mutation would
have made you more likely to die and not pass along your DNA.

-- --

https://jtem.tumblr.com/post/664590992284008449

Op zaterdag 9 oktober 2021 om 22:28:49 UTC+2 schreef I Envy JTEM:

> > That's comparative data.

> The problem with evolution is that we look at the results and then
> work backwards. For this reason we see what happened as more
> of a foregone conclusion rather than one single potential result out
> of many. So instead of looking at HOW things ended up we must
> look elsewhere.

Don't make it more difficult than necessary, it's not difficult,
e.g. just 1 simple example:
humans (vs other primates) have feet with rel.long digital rays
(incl.digits 1 & 5 - and this is even more in human embryos).
No bipedal (kangaroo, ostrich...) or QP runner has very long dit.rays 1 & 5,
they have 1 or 2 central (esp.digit 3) long & strong pedal digits.
Rel.long & strong outer digits are typical of swimming-wading tetrapods.
All other differences with other primates point into the same direction:
fur loss, big brain, SC fat, voluntary breathing etc.etc.

Don't make it more difficult than necessary.
Whether there were crocodiles in the swamps, or sharks in the sea, or lions on the savanna doesn't say anything:
the facts are obvious: we have flat feet + rel.long outer digital rays:
only complete idiots believe their ancestors ran after kudus.

Of course, our feet are not very flat (any more): we are indeed not wading-swimming any more.
(and this makes it too difficult for some people).
How fast we changed, where & how exactly it happened is a matter of debate,
but that we were more aquatic in the past is obvious.
only unscientific imbecils believe Pleistocene Homo ran over savannas.

______

> Evolution is a change, we say "Mutation." Genes "Mutate" and that
> mutation propagates. But because we're talking maybe as few as
> a single individual initially carrying that mutation -- maybe a litter
> but quite possibly only one individual -- the mutation is never going
> to compete. It's going to be breeding with members of the
> population without the mutation, and most likely their offspring will
> the breeding with members without the mutation...
>
> So we need a mechanism to STOP that from happening. We need
> a mechanism to STOP the members without the mutation from
> out breeding, swamping the mutation. And that's usually death.
>
> Something has to kill off the members without it.
>
> Alternatively: The Founder Effect. As few as a single (pregnant)
> individual can become isolated, become a breeding population
> onto itself.
>
> Anyway, back to death...
>
> The most likely cause of death -- speaking ultimately -- and why it was
> our ancestors and not all these others, is migration. They're living off
> the water, seafood, consuming resources and moving on. This supports
> a much larger population density than terrestrial foraging, allowing more
> opportunity for mutations to crop up, but it also means that they're
> encountering differing water depths. They're crossing channels. They're
> wading out further...
>
> What was killing them was the water.
>
> So any mutation that made the water more survivable would have been
> a great benefit, while at the same time the lack of that mutation would
> have made you more likely to die and not pass along your DNA.