Re: An alternative to ST and AAT

pete (VINCENT@reg.Triumf.CA)
31 Oct 1996 02:37:56 GMT

Rohinton Collins (rohinton@collins.prestel.co.uk) sez:

The LCA, assuming it was an
`arboreal quadruped, would be more predisposed to bipedality than the chimp,
`since much of the time it would have stood on two feet, steadying itself by
`grasping upper branches, or reaching for fruit. The valgus angle
`(femur/tibia angle) would most likely more closely match hominids than the
`African apes (note the orang-utan has a hominid-like valgus angle and is
`largely arboreal) which would also aid the transformation to bipedality.

The idea of an arboreal quadruped which spends much of its time standing
on two feet is somewhat ambiguous. What exactly do you have in mind here?
Do you consider the gibbon to be an arboreal quadruped? It uses all four
limbs for locomotion, but uses the front pair quite differently from the
back.

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vincent@triumf.ca <== faster % Pete Vincent
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