Re: An alternative to ST and AAT

Phillip Bigelow (
Sat, 16 Nov 1996 19:33:42 -0800

Thomas Clarke wrote:

> If some primates had developed bipedalism 10 or 20 million years ago,
> bipedalism like that practiced by Australopithecenes and Hominids, then
> the did not evolve very far along an evolutionary trajectory similar
> to A/H or else we would come across ancient artifacts (fossil artifacts?).

Not definatively. There is no gaurentee that a
low-population, geographically-isolated, delicate species of
bipedal primate would be found as a fossil. Given enough
time searching, the odds stay pretty much the same as they were
when one began searching for the fossils.
This subject is getting into the science of "taphonomy", Tom,
and it involves probabilities, sedimentation rates, basin-analysis,
pH of the sediment, numerical abundance of the hypothetical
species, erosion rates, geographical range of the hypothetical
species, re-working of the material, and lastly, this question:

"Do species that inhabit mountainous terrane have a REASONBLE
probability of being preserved in the fossil record, considering
that there are no basins nearby in which to bury the animal and
preserve it for millenia?"

The answer to the question is that these species have an
*extremely* low probability of being found in the fossil record.

To make matters worse:
And if the hypothetical bipedal mountain primates are also
numerically-low in population, the odds of ever finding a fossil
of one of these creatures then becomes vanishingly small.

The correlary is that there is always a possibility that other,
now-extinct bipedal primates of another clade existed. Proving
it is an extremely difficult proposition.

Hope that clarifies this for you. There are no gaurentees of
preservation when it comes to taphonomic processes.