Phyly

Dr. James Adams jadams at EM.DALTONSTATE.EDU
Thu Nov 11 12:31:55 CST 2004


Listers,

         After Mike Ivie's and Curtis Clark's posts from earlier today, I
feel compelled to add one more item.

         The original message asked about presentation of the concepts and
definitions.  It didn't ask about application to the real world!  I never
said anything about how *easy* it is to apply the concepts.  We all know
that homoplasy may be rampant in certain data sets, and certainly will make
it difficult to discern the actual relationships from time to time for some
groups.

         Another person was asking about whether we should work with
paraphyletic groups or not, since that would violate the strict cladistic
approach.  Well, as I said in my first message, I don't personally have a
definite problem recognizing paraphyletic groups, as long as we understand
they are paraphyletic.  There are *plenty* of examples I can point to in
the world of Lepidoptera (my group of interest) alone.  The Noctuidae,
already the most speciose family, could technically be even larger, as
Tiger Moths (Arctiidae) are really one nicely specialized group of
noctuids, numbering more than 10,000 worldwide as well.  Heck, moths and
butterflies is another great example, with the butterflies being one
specialized group branching from somewhere in the middle of the
Lepidopteran tree.  I'm betting that a lot of us work with groups like
this, and we have no problem communicating with other people who work with
these same groups.

         I would, however, have a real problem recognizing and working with
a group that is a known polyphyletic group -- anything that includes taxa
that are not true sister taxa (includes the ancestor) is completely
misleading.  Any group/group name should indicate some evolutionary
relatedness.

         My two cents (or maybe less!).

james

James K. Adams
jadams at em.daltonstate.edu
Phone: (706)272-4427
FAX:  (706)272-2235
Visit the Georgia Lepidoptera Website:
    http://www.daltonstate.edu/galeps/
Also check out the Southern Lepidopterists' Society Website:
    http://www.southernlepsoc.org/




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