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At 08:33 AM 8/9/98 -0400, larryf wrote:
>     I`ve been keeping track of the discussion between Stanley 
>Friesen and Matt Troutman on the relationship between climbing
>and bipedalism. I would think that bipedalism in arboreal species 
>would have more to do with an ability to perch on a narrow branch, 
>(and have the hands free), rather than an ability to climb.

Would that it were that simple.  Bipedalism may have evolved by more than
one mechanism.  Indeed, the difference between dino-avian bipedalism, with
its more-or-less horizontal body, and hominid bipedalism with its fully
erect body, strongly supports a different mechanism in these two cases.

Also, I suspect that true perching did not evolve until *after* flight,
even if avian flight evolved in an arboreal archosaur.  Most non-avian
arboreal forms are quadrupedal, at least in the trees.  And looking at what
birds *do* with perching suggests to me that it originated as a display
and/or ambush mechanism.  (The most general use of perches by birds is to
sing their territorial songs).

May the peace of God be with you.         sarima@ix.netcom.com