Re: AAT Questions...
pete (VINCENT@REG.TRIUMF.CA)
31 Jul 1995 06:16:49 GMT
Ralph L Holloway (rlh2@columbia.edu) sez:
`On 28 Jul 1995, HARRY R. ERWIN wrote:
`> Not speaking as an AAHer, but wouldn't you expect robust limbs, given the
`> forces and moments you would expect to encounter in the water? I don't
`> think I know of any aquatic vertebrate that is particularly gracile. Even
`> penguins have low-drag wings. This probably can be quantified.
`Do most of the aquatic vertebrates(cetaceans, porpoises, otters, seals,
`etc) have "robust limbs" and wide shoulder girdles? If the early
`hominids/hominoids were basically arboreally adapted, wouldn't you expect
`"robust" upper limbs and clavicles keeping the arms laterad to the torso?
`With a 3-5 million year aquatic adaptation wouldn't you expect some true
`convergent evolution of the aquatic apes to include streamlining the body
`shape for continuous locomotion in an aquatic environment, such as we
`find in aquatic mammals? I don''t think robusticity of the limbs, however
`measured can help in this issue, Harry.
`Ralph Holloway.
Now, see, this begins to build into a pattern. Robust arms mounted
on a narrow shoulder. To the extent that this construction causes
no compromise in lung capacity, this seems like a reasonable
adaptation to expect. Rather like the upper body of a sea otter.
--
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vincent@triumf.ca <== faster % Pete Vincent
vincent@freenet.vancouver.bc.ca % Disclaimer: all I know I
% learned from reading Usenet.
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