Re: Crowley Hot-Shot... was Re: tree-climbing hominid

David Froehlich (
Fri, 13 Oct 1995 09:55:08 -0500

On Fri, 13 Oct 1995, Paul Crowley wrote:

> I presume you accept that there were major disadvantages in becoming
> bipedal: i.e. the mother had to use one or both arms to carry her
> child everywhere she went, meaning that she could not run, climb,
> use a club, or throw rocks when in the presence of a predator, nor
> could she sleep in a tree at night. In fact the viability of her
> existence is questionable.
> So the advantages of becoming bipedal must have been enormous.
> Someday I'd like to know what you thought they were.

This is where I think the fundamental disagreement between my approach
and yours is. You assume that bipedalism must have been very difficult
to attain based on what I view as untestable statements about the cost to
a bipedal organism over being quadrupedal.

Why don't you examine the propositions in the intial paragraph and test
them before assuming them. Answer the question "How would I know if they
were wrong".

I just don't buy the asumption that bipedalism -must- have been
difficult. (before you reply that there aren't any bipedal organisms
other than hominids in Africa, remember that this is negative evidence
and rests on the assumption that any quadrupedal organism should be able
to do this which is pattently false, how many organisms in Africa have
positional behavoirs like primates (other than primates) If you don't
start the same way, why should you end up the same way).

David J. Froehlich Phone: 512-471-6088
Vertebrate Paleontology Laboratory Fax: 512-471-5973
J.J. Pickle Research Campus
The University of Texas, Austin, Texas 78712