"why not move on 4 legs" Re: We were never knuckle draggers

Marc Verhaegen wrote:

Yes, that's obvious: knuckle-walking is more derived than bipedalism: in
order to evolve from palm-walking (all primates incL.human infants, except
chimps & gorillas) to knuckle-walking (walking on the dorsal instead of on
the ventral side of the hand), chimps & gorillas needed an intermediary
phase where their hands were +-not used for pronograde locomotion. This
intermediary phase was not arm-hanging (alone): otherwise gibbons & orangs
would knuckle-walk on the ground, but they're palm-walkers. All apes still
walk regularly or occasionally on 2 legs, so the intermediary phase was
(short-legged) bipedalism (probably in combination with climbing arms
overhead).

Marc's explanation of how an obligate biped becomes a quadruped:
"why not move on 4 legs"


Op 03-06-2007 00:50, in artikel
QI2dnVhn2OGsafzbnZ2dnUVZ_o2vnZ2d@xxxxxxxxxxx, MClark <men@xxxxxxxx> schreef:

/Upright walking may not have been uniquely human/
Ann Mcllroy, Toronto Globe and Mail
.

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