Re: An alternative to ST and AAT

Paul Crowley (Paul@crowleyp.demon.co.uk)
Thu, 31 Oct 96 21:01:27 GMT

In article <3275D544.2065@scn.org> bh162@scn.org "Phillip Bigelow" writes:

> Paul Crowley wrote:
>
> > The primate species that adapted to the ground probably did it
> > in the absence of competition. It would not have happened often.
>
> Maybe...maybe not. Just speculation.

No, it's not just speculation. Ecological niches get filled.
The terrestrial primate ones are occupied by large variety.
It's very hard to see how a gibbon or an orang or other purely
arboreal primate could establish itself on the ground in a new
niche in the face of such competition.

Further, purely arboreal species tend to become very specialised
with particular adaptations that virtually debar the adoption of
a terrestrial role. Typically these include a degree of
clumsiness on the ground that amounts to an inability to make
effective progression.

> > > If it happened
> > > with their ancestors, why not in the hominid clade as well?
>
> > The niche would almost certainly have been already filled.
>
> Again...speculation.

You must learn to distinguish speculations from reasoned
conclusions based on known data. The possibility that the
hominid clade derived directly from a purely arboreal LCA
must be regarded as remote.

Paul.