Re: Why Large Gap Between Species...?
HARRY R. ERWIN (herwin@mason2.gmu.edu)
5 Dec 1996 18:59:37 GMT
Geoff Alex Cohen (gac@cs.duke.edu) wrote:
: T&B Schmal (schmal@firstnethou.com) wrote:
: : In article <581tr6$3jc@news.smart.net>, turner@smarty.smart.net (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
: environment).
: 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
: sapiens.
: The Lotka-Volterra equations describe these relationships quite elegantly.
And quite invalidly when you bother to check out real ecologies.
Ecological vicars are very common.
--
Harry Erwin, Internet: herwin@gmu.edu, Web Page: http://osf1.gmu.edu/~herwin
49 year old PhD student in computational neuroscience ("how bats do it" 8)
and lecturer for CS 211 (data structures and advanced C++)
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