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
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".
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 forThe 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:
and how human bipedalism evolved from this locomotion, see our TREE paper: google "Aquarboreal Ancestors".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)
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
It does: Nasalis also wades upright & surface-swims sometimes, got larger, reduced its tail etc.
It does: Nasalis also wades upright & surface-swims sometimes, got larger, reduced its tail etc.
That's logic, not evolution,
That's comparative data.
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.
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