Re: chimps on the savanna? Nooooo.....
pete (VINCENT@REG.TRIUMF.CA)
28 Oct 1995 00:47:03 GMT
Alex Duncan (aduncan@mail.utexas.edu) sez:
`In article <hubey.814567746@pegasus.montclair.edu> H. M. Hubey,
`hubey@pegasus.montclair.edu writes:
`>>The A. afarensis fossils that are available show no evidence whatsoever
`>>of adaptation to aquatic environments.
[...]
`>What do you want to see?
[...]
`Nothing so drastic. I would expect to see that measures of hind limb
`robusticity don't correlate well w/ estimates of body mass taken from
`other parts of the body. Since these hypothetical animals are spending a
`lot of time in the water, they won't be supporting much weight over their
`hind limbs. Therefore, weight estimates derived from hind limb
`parameters such as femoral midshaft diameter or femoral head articular
`surface area should be too small when compared to estimates from other
`methods. I would expect that femoral heads might be more cylindrical
`than in most other primates, as life in the water should lead to largely
`parasagittal movements of the hindlimbs. I would not expect to see
`anteroposterior expansion of the femoral condyles. I would expect to see
`evidence for a capacity for extreme plantar flexion at the tibiotalar
`joint. I would expect to see evidence that full extension occurred at
`both the hip and the knee during the locomotion cycle.
`I don't see any of these things.
I follow, and generally agree with, all these except the last.
Why do you expect to see full extension?
--
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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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