Re: AAT Theory

H. M. Hubey (
10 Oct 1995 04:34:44 -0400 (Gerrit Hanenburg) writes:

>apes.Apes are bad quadrupeds especially on the long distance.
>However the study of Rodman and McHenry(1980) has shown that for a
>chimpanzee walking bipedally is no more and no less energetically expensive
>than walking quadrupedally.If selection for cursorial locomotion was
>significant then any slight variation in the direction of more efficient

Over long distances or short?

A chimp would have a serious back problem if he tried to walk
long distances bipedally. His spine isn't made up for it.
Either he'd get back cramps :-) or his rate of expenditure
using the back muscles so much to hold up his frame would
increase. I suspect that over a short distance it might
be possible to go on perhaps with some oxygen debt.

It's strange to question empirical results but a simple
mechanics contradicts the conclusion that they'd be
equal. The only possibility is that the use of the arms
offsets the use of the muscles of the back but over long
distances it would make a difference.


Regards, Mark