Re: Specification for theories on human evolution

Alex Duncan (
16 Nov 1995 14:01:50 GMT

In article <> Paul Crowley, writes:

>It is my thesis that the adoption of bipedalism would have had
>enormous disadvantages (helpless infants, impeded mothers, no
>safe refuge in the trees at night, etc.) if adopted for any of
>the standard reasons.

You have created a model for bipedalism that virtually no one else would
agree with. Check your "disadvantages":

1) helpless infants. Why helpless? Why are altriciality and bipedalism
connected? (They're not, and the fossil record speaks very strongly on
this issue.)

2) impeded mothers. This is very problematic for me to grasp. As far as
I can see, bipedalism would be an advantage for any female burdened with
a neonate. If the arms aren't required for terrestrial locomotion, that
makes it easier to use them to tend to the infant, should the infant
loose its grasp.

3) safe refuge in the trees. Again, this isn't what the fossil record
tells us. Hypothetically speaking -- if you were left out in the African
equatorial savanna w/ no tools or weapons (and alone), where would you
spend the night? I would sure as hell spend it in a tree (and there's
nothing about my -- or any non-pathological human's -- anatomy that would
prevent me from doing so). I might be uncomfortable at first, but I
suspect that over a period of a week or so, I would become pretty adept
at building nests.

Alex Duncan
Dept. of Anthropology
University of Texas at Austin
Austin, TX 78712-1086