Re: Bipedalism and other
J. Moore (email@example.com)
Wed, 5 Jul 95 10:50:00 -0500
Cf> firstname.lastname@example.org (J. Moore) writes:
Cf> >JM> >Some gorillas, various macaques and the proboscis monkey spend
Cf> >JM> >varying amounts of time in all those places, but show none of the
Cf> >JM> >supposed AAH adatations. They utilise common ape and monkey
Cf> I had heard that probiscus (sp?) monkeys had been picked up by
Cf> fishing boats significant distances from land. You're saying that
Cf> oxygen bell of a nose couldn't possibly have anything to do with
Provide some reference for your statement that the nose of the proboscis
monkey is used as an "oxygen bell". Then explain why this feature isn't
found in females or young. Then explain how the females, without this
feature, swim like the males. I await your detailed reply.
Cf> >JM> >Various environments have been suggested by different AAH
Cf> >JM> >all state that a major reason that these water environments were
Cf> >JM> >necessary for the evolution of bipedalism is to help support the
Cf> >JM> >weight of the animal. Note that this necessarily means that the
Cf> You've got it backwards; it is suggested that some support for body
Cf> weight was required to allow bipedalism (before anatomical changes had
Cf> occured), and water would perform that function.
Which is what I said. Explain to me how that's "getting it backwards".
Cf> If it was rather easy
Cf> and very beneficial for the ape to stand up, why haven't the chimps or
Cf> baboons tried it?
They do...quite often. You are, I take it, completely unaware of all
the literature on primates?
Cf> >Pa> What are the real advantages of wading compared to quadrupedalism?
Cf> We assume he meant 'bipedal vs. quadrupedal wading', as your reply
No, my reply assumes that he said what he meant: that "wading" is
opposite (to be "compared" with) quadrupedalism. Of course he may
simply be, as you suggest, inarticulate.
Cf> >Pa> 1) Better vision across the surface of the water and back to land.
Cf> >If the water isn't over your head, you can see "back to land" just
Cf> >fine with your head at the surface of the water. On land, however,
Cf> >bipedalism for this purpose would be a huge advantage.
Cf> It it's clear or fairly shallow water, you can see the bottom (rocks,
Cf> etc) which you can't see if your eyes are at the surface. You could
Cf> also see fish, patterns of ripples (sharks, etc) and get a sense of the
Cf> currents Please support the opinion that a wider view across land is
Cf> more advantageous than a similar view across water.
I was referring to his claim. At the best of times, the view into clear
water is poor for humans compared to a view through clear. I would not
say that there are no advantages to your claim (as opposed to his), but
would also point out that Morgan's AAT repeatedly refers to a creature
in water up to its neck ("head-out immersion") which negates your
Cf> >Pa> 2) Lower energy usage compared to swimming.
Cf> >Refs, please. I've always found walking through water to be
Cf> >energy-intensive, as water gives such much resistance. But please do
Cf> >provide the references which contradict this impression.
Cf> Consider energy per unit of forward motion. Swimming uses a lot of
Cf> energy moving water around, only some of which also moves the swimmer
But please do provide the references which contradict this impression.
Cf> >Perhaps you could explain how the AAT-hominids defended themselves
Cf> >against fierce aquatic predators such as crocodiles and sharks.
Cf> Besides knowing what areas and times to avoid (I would suspect that
Cf> early morning would be fairly safe against crocodiles ???),
Wrong. Very bad time. You have just been eaten...
Cf> probable there were losses; the birthrate could have made up for them.
Your contention is that the transitional hominids had a birthrate much
higher than that of any of the great apes, or humans? If not, I'm
afraid it's just not enough.
Cf> What's the total yearly loss of lives to shark and crocs?
Cf> -Clara A. N. Fitzgerald email@example.com
As I have pointed out, humans today do not stand around in waist-deep
or deeper water for most of the day, and they have had, for many many
thousands of years, far more effective weapons than even early *Homo
sapiens*, much less the transitional population. In this case, you have
to look for an animal model, as we do in considering the effects of
predators on a land-based transitional population. In the case of an
aquatic population, we have no valid animal model -- ever wonder why?
(Answer: they were all eaten.)
Jim Moore (firstname.lastname@example.org)
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