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

David Froehlich (
Sat, 14 Oct 1995 11:59:08 -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.

I accept nothing of the kind. Any primate mother has disadvantages when
rearing offspring, but they seem to get along quite fine? How do they do
this? There are a variety of responses including parental investment
either in terms of protection or food sharing. Why are these not an
option? Especially since all hominoids live in comunal groups.

> >
> > 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".
> Hominid mothers cannot do those things now. Primate (hominoid) ancestor
> mothers could. The change happened in connection with bipedalism. (I'd
> prefer to define the change *as* the acquisition of bipedalism, but that's
> not quite the same point.) What else makes any possible sense?
> If A=B and B=C, therefore A=C. Asking how I "test" whether A=C or how
> I "know" whether A=C does not makes sense to me. The same applies to
> the questions you suggest. If the statements are wrong, then the laws
> of logic must suddenly have been abolished. Or am I missing something
> completely? Please enlighten me.

A=C only if A is a true statement, A=B is a true statement, B is a true
statement, and B=C is a true statement. All I was asking for is for you
to provide evidence for your premises. I do not quibble with the logic,
I quibble with the basic assumptions in your statements. Coincidence
does not demonstrate causality.

You still have not addressed my basic question of how you would know if
any of the asumptions are wrong?

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