Diversity of apples

[Thomas Lammers]

At 12:27 PM 9/29/00 -0300, you wrote:

>OK, let's continue with apples: If, as commonly supported in systematics,
>the terminal unit is the species, we have only one single scientific name
>for  apples. Thus the systematists would not even realize an eventual
>decrease in apple diversity through the extinction of many of the formerly
>cultivated apple varieties.

Your "if" is flawed and your "thus" wouldn't  necessarily follow even if it
weren't.

Species is considered a *fundamental* rank in the hierarchy.  But there are
ranks within it: subspecies, variety, form.  I guess by "terminal" you mean
in a cladistic sense.  But I certainly have seen cladograms of genera and
other higher taxa.  And in reality, evolution does not act on species but
on populations.  So I do not accept your "if" as "supported by systematics".

Everything that is different does not have to christened with a name,
certainly not with a species name.  Systematists understand that some
species are more variable (more diverse) than others.  A lot more variation
is included in Pyrus malus, with all its anthropogenic "populations", than
in, e.g., Ginkgo biloba.  The point is not how much diversity a species
contains, but rather how well demarcated it is from related species.  We
not only judge membership in a species by similarity/reproductive
capability among conspecific individuals, but also by how
different/reproductively isolated those individuals are from other such
groups of individuals.  Ying *and* yang.

Systematists are NOT going to be oblivious to extinction because every
discernible entity does not have a name at species rank.


Thomas G. Lammers, Ph.D.

Assistant Professor and Curator of the Herbarium (OSH)
Department of Biology and Microbiology
University of Wisconsin Oshkosh
Oshkosh, Wisconsin 54901-8640 USA

e-mail:       lammers at uwosh.edu
phone:      920-424-7085
fax:           920-424-1101

Plant systematics; classification, nomenclature, evolution, and
biogeography of the Campanulaceae s. lat.
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