Re: Bipedalism in different substrates
From: Algis Kuliukas (algis_at_RiverApes.com)
Date: 06/07/04
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Date: 6 Jun 2004 21:13:09 -0700
"Michael Clark" <biteme@spammer.com> wrote in message news:<10c67ncropjlc1a@corp.supernews.com>...
> "Algis Kuliukas" <algis@RiverApes.com> wrote in message
> news:77a70442.0406051834.5d3ea0af@posting.google.com...
> > "Michael Clark" <biteme@spammer.com> wrote in message
> news:<10c3hf2k4lve421@corp.supernews.com>...
> [..]
> > > I say that since gibbons are a member of
> > > that close group to which we too belong, and that since they have
> > > incorporated a behavior around whose development *water is
> > > not connected*, then it is possible for another member of that group
> > > (us) to have similarly evolved. In fact, it is probably fact.
> >
> > You say 'similarly evolved' as if gibbons were obigate terrestrial
> > bipeds.
>
> No, I do not. That's you putting words in my mouth.
>
> > They are not. They are very specialised brachiationists who
> > have become so arboreal that when on those very rare ocassions they
> > are the ground they find it easier to move bipedally, at least for a
> > few seconds. Was the LCA of Pan-Homo a gibbon-like brachiator? We
> > don't know, but the prevailing view, as far as I understood it, was,
> > no, it wasn't.
>
> They move bipedally on the ground, awkwardly, for whatever it takes
> to get to the next tree. They also move bipedally in the *trees*. They
> do this *without* being under the influence of water --which is my point,
> and one that you cannot dispute.
I don't dispute it. Like merecat peering and antelope bush feeding,
they are rare incidents of bipedality. What you seem to have a problem
understanding is that they are *minor* in their behaviour context. In
trees how much time do gibons move bipedally? (2%? Have you got any
idea?) On the ground, they move bipedally for a few seconds between
trees but if they were denied access to a tree to climb they'd soon
get down on all fours otherwise we'd call them obligate bipeds and
you've just told me that you're not doing that.
See that? On the ground, after a short period of time, a gibbon would
revert to quadrupedalism if it didn't have another tree to leap up and
- key point - it wouldn't die for it. An ape in water, on the other
hand (which is also, I grant you a rare behaviour) would not revert to
quadrupedalism because if it did it would immerse it's face in water.
It's only other choice therefore is to swim and, gibbons, orangutans,
chimps and bonobos, according to the literature, do not swim.
> They represent a case where bipedalism
> exists ~outside~ the wading context and as such obliterate your claim that
> water is *required* in the development of bipedalism. I have not said
> that the LCA was a gibbon-like brachiator. That's you trying to invent
> diversions. I took pains below to make that clear.
I never said it was *required* just that it is the most simple and
plausible model. I've said again and again that the brachiationist
model is not incompatible but complementary. It's you who are being
absolutist and pig headedly certain: 'it was brachiation and *not*
wading!'
If the Pan-Homo LCA was not a gibbon-like brachiator why on earth do
you think gibbons behaviour has any bearing on the origin of hominid
bipedality?
> > > You, OTOH,
> > > say that our own bipedalism can probably be traced to wading because
> > > you've seen chimps stand in water.
> >
> > Chimps, bonobos, gorillas, and orangutans. Not just that, but that in
> > waist deep water they have pretty much no option but to move
> > bipedally. That's the key point, w hcih you (understandably, so as to
> > keep your counter argument alive) keep forgetting.
>
> Hey, I have no problem seeing all apes stand in water. After all,
> they are all large-bodied, vertical-trunk, adept climbers who practice
> some form of bipedalism on the ground and in the trees. Why wouldn't
> they stand in shallow water? Maybe they don't want to get their hands
> wet. But they did not *aquire* it there.
They didn't aquire it there, we did (according to the wading
hypthesis). They are not bipeds.
> > > I've got the well-established
> > > evolutionary history of the *group*, the physical anatomy, ...
> >
> > None of which is in any doubt and none of which contradicts the wading
> > argument in the slightest.
>
> You misspelled "supports".
Tell me how early ape phylogeny contradicts the aquarboreal model
then.
> > > the geology, the ecological history, the fossils and their
> distribution,...
> >
> > We share none of the last 23My of history with Hylobates, but 16-18My
> > of that time span we do share with the ancestors of Pan. Most of that
> > time span the fossil evidence, ecological history etc suggetss that
> > African hominoids, but not necessarily Hylobatian ancestors, lived in
> > wet and wooded habitats, often gallery forests. So how you can make
> > such a claim is beyond me.
>
> That's because alot of stuff is beyond you. We're talking about
> bipedalism and hominids and how they got that way. Don't go
> running for gibbons like you think you need to discredit them.
Your the one using gibbons as a last stand against the wading model.
You put it up there, so I'm knocking it down.
> That would be missing the point, again. There is nothing in the
> ecological history, the geology, or the fossil record that puts
> proto-hominids *in the water*.
Look at the paleogeography of NE Africa, Southern Europe and Eaurasia
around the mid-Miocene. See where the Miocene apes were found. Now
tell me, with a straight poker face, that ape evolution was unlikely
to have been influenced by water.
> There is nothing, for example,
> in your favorite phrase "wet and wooded" that implies that
> there was more *standing water* in these environments.
Nothing except blatantly obvious logic.
> If
> anything, wet means more rainfall and thus a coorespondingly
> different flora. Even if there *were* more standing water,
> you've consistently failed to put our ancestors in it.
If there was more rainfall there would be more wetland areas. I cannot
prove our ancestors went in the water any more than you can prove that
they didn't. But (and this answers the question of the uncivil Jim
McGinn - who I won't respond to until he is a bit more civil) if there
were more wetland areas then there were more food-rich habitats
waiting to be exploited. Food, floodings, escaping land-based
predators, crossing to new terrain, keeping cool, are just some of the
reasons why apes would get into the water. Avoiding aquatic predators
is the only reason not to.
150 years of just *assuming* they didn't go in water has left us with
a muddle of models which are contradictory, complex and simply do not
yet answer the fundamental question 'why did some apes start moving
bipedally but not others?' I'd say that this kind of suggests that,
perhaps, it's about time we reconsidered that assumption, don't you?
Probably not. You're presumably, happy with the subject of human
evolution being in compete disarray and with the science of
paleoanthropolgy unable to answer the most basic, simple question
about the way we are.
> > > the backing of 99.9% of the published literature, ...
> >
> > I don't dispute that the vast majority of the literature does not even
> > consider the wading hypothesis, but I think that it is just a mistake.
>
> Yea, your're right and 999 professional paleoanthropologists are
> wrong. Can you say "HUBRIS"?
Sorry about that. I think people are foolish to dismiss this
hypothesis on the basis of rumour - which is all that has been used so
far. From a theoretical point of view it makes more sense than any of
the others. For example, it's the only one that can say - if this ape
goes bipedal it lives, if it goes quadrupedal it dies - and yet it
isn't even discussed in the texts. I think that's just a shocking
indictment on a science that has been funded with enormous amounts of
tax payers money to do the thinking about our evolution for them. If
there was some data that proved that our ape ancestors could *not*
have gone in the water, I'd be more understanding, but the irony is
that almost all the fossil evidence places hominids right next to
water sources. How did that happen? They've just *assumed* the
relationship was due to taphonomy. Brilliant.
> > > and this big stick that says I'm right.
> >
> > Well that's the only thing that really counts as far as you're
> > concerned.
>
> That's what I like about you navel-gazers. No sense of humor.
Oh, so the 'big stick' was a joke. I see. Trouble is, Michael, you
throw ad hominems in so often it kind of makes it hard to tell whether
you're joking or just throwing your usual insults.
> > > You have...well, you have your wet ape.
> >
> > Apes not 'ape'. I have anecdotal evidence that all four great ape
> > species wade bipedally in shallow water and good evidence that in
> > bonobos they are bipedal pretty much all the time that they're in
> > water. This evidence back up the common sense logic that says in waist
> > deep water an ape has pretty much no choice but to move bipedally.
>
> You keep insisting that ape[s] have no choice. Others, besides
> myself, have ever so gently reminded you that apes DO have
> choices --one of many of which is to assume the position. They
> have this choice because they brought it down out of the *trees*
> where they aquired it.
I undertsnad that in trees they have a choice and on the ground they
have a choice but in waist deep water whatever choices they might
have are severely limited.
> Employing it in water is just using it in a
> different substrate --the behavior is there, regardless of the moisture
> content and whether you like it or not.
In waist deep water what choice does an ape have if it can't swim?
If it can swim and the water is bearly deep enough to reach it's hips
what's it going to do? When you're at the beach and the water's barely
up to your hips what do you do?
In waist deep water does an ape go bipedal or quadrupedal? What would
happen if it tried to go quadrupedal? Where else in the natural world
is the distinction so clear and pronounced between the two?
> > The paleohabitats are consistent with it, the anatomy of early bipeds
> > is consistent with it.
>
> There is nothing in the paleohabitats of the African continent nor
> in the anatomy of early bipeds that screams ~water~. Don't think so?
> Produce it.
In the mid-Miocene - the coasts of NE Africa/SE europe/SW asia changed
every five minutes. That's where most of the Miocene apes were.
Sahelanthropus was placed smack bang in the middle of paleo-lake Chad.
Later hominids in wet and wooded, largely gallery forest, habitats.
Why do you just *assume* taphonomy, why not be daring for once in your
life and imagine that the fact that they died there just might
indicate that they actually lived there too?
> > It should be discussed in university level textbooks as a distinct
> > possible solution to the problem of hominid bipedalism, but it isn't.
> > You haven't given one good reason why it should not be there.
>
> I'll give you two:
> a. It enjoys no scientific support
Well considering there has been practically no study of the hypothesis
that's no big surprise is it. The question is why has no objective
minded scientist thought about testing it?
> b. Its proponents are all lunatics.
Yes, I know. It's *so* radical an idea only someone completely mad
would consider it. Human ancestors actually *stepping* into the water
- hah - crazy, that.
[Note to future newsgroup archive researchers... See this? Here's a
guy who thinks the wading hypothesis is so crazy he's actually
suggesting that anyone who is a proponent of it must be a lunatic. I
expect you'll file this alongside similar references to the early
treatment of Copernicus, Darwin etc ideas]
> > > >Secondly the immediate ancestors of Pan/Homo were
> > > > probably not brachiators like gibbons and you'd have to go a lot
> > > > further back, probably, to find a Homo ancestor that was gibbon-like.
> > >
> > > You seem to be missing your own point. The LCA did not have
> > > to be a "X", only a large-bodied, vertically oriented, hand
> manipulating,
> > > feet walking ~something~. Gibbons are only an example of a primate
> > > that is capable of bipedalism.
> >
> > No. It's you who is missing your own point. Gibbons are only bipedal
> > on the ground *because* they are specialist brachiators, otherwise all
> > arboreal primates would be bipedal on the ground, right? And, of
> > course, generally they are *not*. Of the 300 or so species of primates
> > most are arboreal but only a handful of those have this wierd tendancy
> > to hop, skip and jump bipedally whilst on the ground - the vast
> > majority go quadrupedal.
>
> How many species of apes are there, Algis? Do they all share
> a brachiating/climbing ancestry? Do they all exhibit bipedal behaviors
> in and *out* of the water? What did you say 2 + 2 was again?
Assuming 11 species of gibbon, 2 species of Pongo, 2 of gorilla and 2
of Pan - and assumig that humans are not apes - 17. I suspect they do
all share a brachiating ancestry. Yes they all exhibit bipedal
behavious in and out of water. 4. And your point is....?
I don't dispute any of that. But you seem to (but haven't yet written
it down in black and white) dispute that in waist deep water apes have
no choice but to move bipedally.
> > > They, in their particulars, need not be
> > > some objectified "goal". I see the last denizen of the trees as larger
> > > bodied, more of a climber --not resembling a gibbon or practicing their
> > > form of brachiation in the least. And I see a shift in diet between
> more
> > > fruits and leaves to a more generalized diet (including more meat) which
> > > a shift to more ground foraging would support. Whether or if one of
> > > these things drove the other, or the timing, it's impossible to say.
> Add
> > > to that mix the subtle interplay of ecology and the weather and pretty
> > > soon you have some potent possibilities.
> >
> > You're like a wizard leaning over his magical brew with steam
> > everywhere, obscuring the details of what's actually going on... All
> > we can hear is your mutterings...take one gibbon, brachiator, take
> > away a little frugivory, and add a bit of carnivory and... hey presto,
> > hocus-pocus, abracadabra - a bipedal hominid emerges! It's all wishful
> > thinking based on faith and nothing more.
>
> No, it isn't. It is based on direct observation of gibbons, the other
> apes, and their shared developmental history and locomotor repertoire.
So why aren't gibbons obligate bipeds too?
> > Why did some apes go bipedal
> > and not others? Can you give an answer that makes sense to a ten year
> > old? No, all you have is: 'Evolution moves in mysterious ways, my son,
> > have faith. It happenned.'
>
> I wasn't aware that I was speaking with a ten year old.
Only in my youthful good looks.
> > The wading hypothesis needs no such hocus pocus. Apes that moved in
> > water more became bipedal, apes that moved in water less did not.
> > Simple.
>
> Yea, except for the evidence thing.
Name me one bit of evidence that contradicts it.
Algis Kuliukas
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