Re: Bipedalism in different substrates
From: Algis Kuliukas (algis_at_RiverApes.com)
Date: 06/11/04
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Date: 11 Jun 2004 08:47:36 -0700
"Michael Clark" <biteme@spammer.com> wrote in message news:<10chq8llpk4ua36@corp.supernews.com>...
> "Algis Kuliukas" <algis@RiverApes.com> wrote in message
> news:77a70442.0406100744.3a05efed@posting.google.com...
> > "Michael Clark" <biteme@spammer.com> wrote in message
> news:<10cgeia3185eg4a@corp.supernews.com>...
> > > "Algis Kuliukas" <algis@RiverApes.com> wrote in message
> > > news:77a70442.0406091546.53762656@posting.google.com...
> > > > "Michael Clark" <biteme@spammer.com> wrote in message
> > > news:<10ce5e7tapb8d6e@corp.supernews.com>...
> > > [...]
> > >
> > > > So why aren't gibbons obligate bipeds? Don't you see that this alone
> > > > just isn't anywhere near enough to turn an ape into a biped without
> > > > hocus pocus.
> > >
> > > Why is the sky blue? Frankly, I don't know but it seems to me
> > > that my vision is adequate enough to see a generalized arboreal
> > > ape, facultatively bipedal "because of its' life in the trees", moving
> > > onto the ground because: a) the trees disappeared, or b) ground
> > > foraging moves from a 30% to a 50% component of its lifeway --
> > > or some combination of the two. Sounds perfectly reasonable to
> > > me. No hocus pocus involved. That's just you trying to make the
> > > alternatives impossible.
> >
> > Funny. You're convinced about the brachiationist model's plausibility.
> > Rich is convinced about the meat carrying model and Jason's convinced
> > about energy efficiency model. In my book they're all incompatible
> > with each other and yet you're, all three, convinced that the wading
> > model (which compatible with any of them) is wrong. Ironic.
>
> What's funny about it? Your thumbnail caricature of what you think
> these people might support? Yea, that's funny. You *daily* display
> an abysmal lack of reading comprehension so what are these people
> to think? You've got some kind of handle on these ideas? Yea, that's
> laughable.
Well I can only go on what they have written. You have argued mainly
in defence of a brachiationist model - against the wading model. Rich
has argued mainly in defence of carnivory and meat carrying against
the wading model and Jason has done the same in defence of the enrgy
efficiency model.
Now are you disputing that? Or is it just more waffle, more hocus
pocus. 'Oh our arguments are far more complex and mysterious than
that.'
If you do accept that these are the models being put up against the
ading model why don't you engage in thinking for a moment about the
compatibility of these models. Think about how compatible the energy
efficiency model is with, say, the climbing model. Perm each one
against the other and then tell me, with a straight face, that the
wading model is the odd one out - the one that's completely at odds
with the others.
> > > [...]
> > >
> > > > Waist deep water is the only place on earth where an ape has to move
> > > > bipedally, right. But I'm not suggesting it's the only place on earth
> > > > hominid ancestors ever moved.
> > >
> > > "There you go again". So what makes an ape move bipedally when
> > > he/she is out of the water?
> >
> > Nothing. But (and this is the point) if ape group a moves through
> > water more than ape group b, then a is more likely to move bipedally
> > on dry ground too because it has likely moved through a full range of
> > water depths, including those that are very shallow.
>
> So then why do they do it? You're not going to deny that apes
> practice bipedal behaviors *out* of the water, are you? Specifically,
> why do gibbons walk and run bipedally *in the trees*?
Because sometimes they have no choive, because sometimes the benefits
outweight the costs and the risks, of course.
How many times do I have to write that I don't deny that apes practice
bipedalism out of water before you actually understand it? The point,
for the gazillionth time, is that in waist deep water an ape has very
little choice (wade, splutter or drown) but on land even your famed
gibbons would get down on all fours after a few seconds of bipedality
if there were no handy tree - and not die for it.
> > > (Maybe you should break the news to
> > > those gibbons. You know, whisper in their little ears about the fact
> > > that there's no waist deep water up in them thar trees and that they
> > > can safely revert to all fours.)
> >
> > And maybe you should answer my questions with something more than the
> > usual [...] ... how much time do gibbons move bipedally in trees (is
> > it more than 2% or less?) And, if a gibbon is denied a handy tree to
> > leap up, for how long, exactly, does its even rarer terrestrial
> > bipedality last?
>
> I like to delete your mindless spew every once in a while just
> to keep the bandwidth down to something manageable.
Oh, sure you do. It's got nothing to do with the fact that the data
backing your brachiationist argument is almost non-existant. Yes, we
believe you, Michael.
> As for
> your question, I don't have the figures that you seek.
Why am I not surprised?
> I would think
> that since you're the captain of that leaky old boat (your "hypothesis")
> *you* would be interested in anything that challenged it. You want
> figures? Go get 'em.
Oh right, I should get them. Ok I will. And when I return with the
data you will, no doubt, claim that they are not relevant.
> But don't get too bent out of shape when you
> discover that they're much greater than your 2% figure above.
Yes, *much* greater - maybe even 2.5%. No, that's stretching it I
know.
> Just
> keep this in mind: Your 100% of virtually nothing is far smaller than
> the *much greater than* 2% of common movements.
The point is that if you put an ape in water you increase it's
bipedality. If you put an ape in a tree you don't. But I'm beginning
to realise that this astonishingly simple point is just beyond you.
> And one more
> thing --gibbon bipedalism is something that has developed without
> the influence of water.
Yes, we know. But how come only one primate out of 300 became an biped
then?
> > I can, of course, answer similar questions on wading...
> > Bonobos in captivity are 92% bipedal whilst moving in even very
> > shallow water.
>
> 92% of what percentage? Bonobos spend what percent of their
> *total time* in the water?
It depends on how much their habitat is exposed to water, of course.
If they don't have to go in the water they chose not to, but Myers
Thompson's study in wild bonobos found them to be 24% bipedal. I
suspect (but I do not have the figures) that almost all of that 24%
was spent in shallow pools. It's logical to think that because their
'background' bipedalism in trees and on the ground is about 3%.
> > Bonobos in the wild have been recorded at 24%
> > bipedality whilst feeding in shallow pools around the Congo.
>
> You mean they spend 76% percent of their *time in the water*
> doing something *other than* bipedalism?
No I mean they spend about 20% of their time in the water and 24% of
their time moving bipedally. There's a clear *causative* link that is
absent from all the other models in extant apes. But then, you're not
really interested in causative links you're only interested in hocus
pocus links.
> > In
> > waist-deep water an ape would *never* chose to move quadrupedally
> > because if it did it's face would get immersed in the water.
>
> Unless, of course, that ape chose any one of a myriad of other choices.
> Come on, Algis, this was stupid the *first time* you said it. It still is.
'Myriad' of choices, eh? Name me one other choice if it can't swim.
> > > [...]
> > >
> > > > Arboreality gives apes an upright stance. Therefore it answers the
> > > > argument 'well why don't dogs go bipedal in the water?'
> > >
> > > You're almost there, Algis. Just a little more critical thinking.
> > > I'd say, oh, another 500 posts or so ought to do it.
> >
> > Arboreality, of course, is a pre-requirement for bipedalism but it's
> > not enough on it's own. If it was enough on it's own how come only one
> > out of 300 or so largely arboreal primates move bipedally?
>
> Are there 300 large-bodied, tailless, brachiaters/climbers? No?
> What sort of locomotor behaviors do those species share? (2 +
> 2 is 4, Algis)
Oh so now you are keen to draw the line at hominoids. You are happy to
include gibbons as apes but not one inch further. Ok, fine. How come,
out of the 17 species of tailess brachiator/climber hominoids only one
became bipedal? The odds are still stacked heavily against arboreality
alone being the decisive causative factor.
> > Don't you
> > see how this is a show stopping problem to that argument?
>
> No, I don't. Please explain.
It relies on hocus pocus. We have not one jot of evidence that
arboreality alone can cause an obligate biped but never mind,
evolution works in mysterious ways.
> > To wish it
> > away, you use hocus pocus. I don't need to wish it away, because the
> > wading hypothesis answers the problem perfectly without any magic
> > wand. In water apes move bipedally therefore the more it moves through
> > water the more bipedal it is.
>
> But they are *already* facultatively bipedal, Algis. And they don't, by
> your own admission, *typcially* move in water. And what is this "wish away,
> hocus-pocus" stuff? Is that you trying to ignore the gibbons? (Chuckle)
Yes, they're already facultative bipeds on land and in trees but in
waist deep water every ape is an obligate biped. I don't ignore
gibbons but after 23 million years their importance fades into the
distance.
Algis Kuliukas
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