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Re: Bipedalism and other factors and AAT
J. Moore (j#d#.moore@canrem.com)
Thu, 15 Jun 95 09:25:00 -0500
He> A clarification of at least one person's version of the AAT is that the
He> environment was fresh-water, rather than salt-water. Since the major
He> alternative (the wooded savanna ape) was also tied to water, there
He> appears to be a compromise available--an ape specialized for life in
He> gallery forests, with arboreal, terrestrial, and semi-aquatic components
He> to its substratum adaptation. Is there a way of testing this? Are there
He> species that people can identify with comparable adaptations? (I have a
He> few in mind, myself.)
He> Harry Erwin
Some gorillas, various macaques and the proboscis monkey spend
varying amounts of time in all those places, but show none of the
supposed AAH adatations. They utilise common ape and monkey locomotor
behavior (a combination of quadrapedalism, brachiation, and bipedalism)
in each of these places. All are overwhelmingly quadrapedal on the
ground and in the water, despite claims by some AAH proponents that they
inevitably effect bipdal posture when in the water.
Various environments have been suggested by different AAH proponents;
all state that a major reason that these water environments were
necessary for the evolution of bipedalism is to help support the body
weight of the animal. Note that this necessarily means that the animal
must be well over waist deep in the water during much of the time that
it isn't sitting or lying. Knee-deep water isn't going to help support
body weight. Another major reason used is the claim that this
chest-deep water environment is much safer than being out in a
relatively open area where you have a chance to spot predators, hence
the other post(s) on the subject of predators.
Jim Moore (j#d#.moore@canrem.com)
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