[Taxacom] Underlying synapomorphy

[Kipling (Kip) Will]

"Underlying synapomorphy" is more or less equivalent to the notion of 
atavism and largely overlapping with orthogenesis. Taken as hypothesized 
explanations of observed patterns these are relatively harmless as long 
as one recognizes what is actual observation and what is a good story.
But confusing pattern and process is a venerable part of our field I fear.

If taken as a priori truth, a model of how character state distributions 
came to be as they are, or how they "should" be distributed, these can 
lead to a dangerous ability to explain away any pattern one does not 
like. Or perhaps more accurately, a preferred grouping is determined and 
any conflict (patterns of homoplasy)can be dismissed ad hoc. "These 
belong in a group because they share an underlying synapomorphy" could 
be used to justify a preferred grouping sans any observable evidence 
supporting such a grouping. Studies of development or genetics could 
provide actual synapomorphies, shared and observable. No one would need 
to call them "underlying synapomorphies."

kip

-- 
Kipling W. Will
Associate Professor/Insect Systematist
Associate Director,Essig Museum of Entomology

mail to:
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University of California
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phone 510-642-4296
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