Re: Bidpedalism

4 Jun 1995 21:50:38 GMT

David Rowe ( wrote:
: >The interesting question is in exactly what environment an arboreal ape
: > would find terrestrial adaptations an advantage.

: This is the bit that I find very hard.

Not really. A selective advantage need only exist for a few hundred or
thousand generations for the corresponding features to fixate. Not long
at all. BTW, Mountain Gorillas find terrestrial movement an advantage
when dealing with the threat of a predator--to the point that they will
usually climb down from a tree to flee on the ground. (Of course,
gorillas and chimps are probably more terrestrial than A. and Homo

: Presumably this evolution took a long time with the same evolutionary
: pressure (2mY?). Does this 'right' environment exist anywhere at all
: now?
: I am not aware that this 'right' environment is available anywhere. I
: get worried about having to invent 'just right' environments that persist
: for millions of years.

: David

Harry Erwin
PhD student in comp neurosci: "Glitches happen" & "Meaning is emotional"