common names/systematics
DR. JAMES ADAMS
jadams at Carpet.dalton.peachnet.edu
Thu Jun 10 10:47:41 EDT 1999
John Grehan writes, about species concepts:
> The former concept is essentialist in that it requires spatiotemporally
> unrestricted essences that are true for all places and time (which is
> kind of anti-evolutionary since essences can't evolve) and includes
> phylogenetic species concepts and biological species concepts. Only
> the species as individuals concept allows for evolution.
I would argue that species are probably rarely actually treatable as
individuals. What probably really *does* respresent evolutionary
individuals are *populations*. I don't truly believe that a
widespread species has enough gene flow so that if major climatic
change takes place all populations will respond all in the same
fashion, as a single unit. It is different *populations* of a
species that are potentially under different selective pressures, and
only if the species is represented by one population only will the
*species* respond as an individual. If there is a very broadly
dispersed population of a species, then widespread gene flow actually
*resists* change within smaller subsets of that population. At any
rate, I doubt that species are truly *evolutionary* individuals in
most cases.
James
Dr. James K. Adams
Dept. of Natural Science and Math
Dalton State College
213 N. College Drive
Dalton, GA 30720
Phone: (706)272-4427; fax: (706)272-2533
U of Michigan's President James Angell's
Secret of Success: "Grow antennae, not horns"
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