All Politics is Local
ueymi at GEMINI.OSCS.MONTANA.EDU
Mon Nov 11 08:35:53 CST 1996
The current debate between morphological and molecular species
descriptions is a false dicotomy, and simply feeds into the division of
systematics into 2 camps (or more if you are a good splitter),
each with a superiority complex. Just as all politics is local, all
taxonomy is morphological -- it is just a matter of scale!
I will bet that someone in the 18th century published a complaint about
taxonomists dividing species by characters that "can only be seen with
the glass," and then explained that such divisions are artificial, and no
one but taxonomists will care.
Then, in the early 19th century, someone protested that species were
being divided by characters "of microscopic proportions", and that
taxonomists were bringing the whole enterprise into disrepute.
Early in this century, Dr. George Horn protested the extreme division of
beetle species by Col. Thomas Casey, an engineer who happened to have better
optical equipment than Horn the physician (Col. Casey loved his scopes so
much he was buried with one of them). While Casey's species concepts
for many larger (in physical size) groups have been pushed aside as
intraspecific variation, in the tiny aleochorine staphylinids he was the
first to realize the tremendous diversity of species, identifiable only by
then-seen-as tiny and obscure characters.
A little later, Dwight DeLong was derided by Herbert Osborn for using
microscopic preparations of leafhopper genitalia to divide up species
previously recognized by color patterns. Osborn predicted this would bring
DeLong into disrepute for discussing such base and obscure subjects.
Over the next 80 years, the understanding of leafhopper diversity
exploded, and today virtually all leafhopper systematics is based on
Mid-century, black fly species began to be described based on
chromosome banding patterns, and doom was predicted by those who cried
"no one will respect us!" Amazingly, with the insight from the
chromosomes, external morphological differences were discovered, and
chromosomes are a standard part of blackfly descriptions today.
Now we have DNA, RNA, isozymes, etc., and the same argument pops up.
Yet, we are not talking about Aristotelian "essence" here, a molecule is
a physical structure! A series of units put together in a unique
pattern is as morphological as hair, it is just smaller. We still use
the same sifting of overlapping variation vs. uniqueness that we always
have, although the avant-guarde always try to convence everyone else they
are 'way out front. This debate too will pass, but the discussion will rise
again at the next advance. Those too important to learn from history will
surely repeat it!
Lets worry about how to document the natural world before it goes away,
rather than argue about the importance of the scale we work at.
Michael A. Ivie
Department of Entomology
Montana State University
Bozeman, MT 59717
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