Re: Why Large Gap Between Species...?

Geoff Alex Cohen (
5 Dec 1996 16:03:20 GMT

T&B Schmal ( wrote:
: In article <581tr6$>, (Nat
: Turner) wrote:
: > This has never been clear to me. Now that we've established man's
: > origins, how do we explain the absence of all his closely related
: > sub-species?

: Good question. Lions, cheetahs, leopards, wolves - all survive in Africa
: and they *don't* dedicate themselves to wiping each other out.

Basic demographic theory would tell us that when two species compete,
either an increased population of species 1 inhibits itself more than
it inhibits species 2 (because of the competition), or it inhibits
further growth of its own population more than it inhibits growth of
the competing population (because of the carrying capacity of the

Two competing species can only co-exist if they both inhibit their own
population as they grow more than they inhibit their competitor.
This is obviously what's happening in coexisting carnivore population.

So I theorize without evidence other than extinction of all other hominid
(hominoid?) species that homo sapiens can outcompete other hom* species
to the extent that an increased number of homo sapiens inhibits the
population of competitors more than it inhibits the population of homo

The Lotka-Volterra equations describe these relationships quite elegantly.