Re: AAT Questions...

J. Moore (
Sat, 5 Aug 95 19:38:00 -0500

Vi> Ralph L Holloway ( sez:
Vi> `On 28 Jul 1995, HARRY R. ERWIN wrote:

HE> Not speaking as an AAHer, but wouldn't you expect robust limbs, given the
HE> forces and moments you would expect to encounter in the water? I don't
HE> think I know of any aquatic vertebrate that is particularly gracile. Even
HE> penguins have low-drag wings. This probably can be quantified.

RH> Do most of the aquatic vertebrates(cetaceans, porpoises, otters, seals,
RH> etc) have "robust limbs" and wide shoulder girdles? If the early
RH> hominids/hominoids were basically arboreally adapted, wouldn't you
RH> expect
RH> "robust" upper limbs and clavicles keeping the arms laterad to the
RH> torso?
RH> With a 3-5 million year aquatic adaptation wouldn't you expect some
RH> true
RH> convergent evolution of the aquatic apes to include streamlining the
RH> body
RH> shape for continuous locomotion in an aquatic environment, such as we
RH> find in aquatic mammals? I don''t think robusticity of the limbs,
RH> however `measured can help in this issue, Harry.
RH> Ralph Holloway.

Vi> Now, see, this begins to build into a pattern. Robust arms mounted on a
Vi> narrow shoulder. To the extent that this construction causes no
Vi> compromise in lung capacity, this seems like a reasonable adaptation to
Vi> expect. Rather like the upper body of a sea otter.
Vi> <== faster % Pete Vincent
Vi> % Disclaimer: all I know I
Vi> % learned from reading Usenet.

And very unlike that of hominids. Where are the shorter limbs one
would expect in an aquatic animal? (Not to mention the small or
non-existent ears; but then this part of the thread was about
features visible in potential fossils).

Jim Moore (

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