"Confirmed" synapomorphies

[Ken Kinman]

Dear All,
     In the classes & clades thread, Pierre correctly stated that "lost
legs" is a confirmed synapomorphy among tetrapods.  This has been repeatedly
confirmed over and over again in tetrapod groups that are legless by using
paleontological, developmental, molecular, and other lines of evidence.  The
real problem arises when a synapomorphy is *assumed* to have been confirmed,
but not by such direct evidence (rather, just by phylogenetic inference
alone).  This is exactly the kind of thing I am challenging at the present
time.
     The character state "lost radulae" has long been considered a reversal,
and cladistic analyses of molluscs routinely indicate that it is a
synapomorphy for Bivalvia.   But I still have yet to find ANY good evidence
that bivalve molluscs ever had a radula, and I strongly suspect that
misrooting and phylogenetic circular reasoning (self-reinforcing inferences)
are to blame for this problem in malacology.
     How do you get those with the malacological expertise to examine a
bivalves-first hypothesis seriously instead of just rolling their eyes and
casually dismissing it as so improbable that it's not worth considering.  I
continue to present my interpretation of the evidence, and explanations of
how it better fits the gradual evolution of torsion in gastropods (and
euthyneury evolving into streptoneury).  Also the gradual evolution of
radular morphology, with simple tooth-puncturing of algae cells preceding
the complicated rasping radulae that can tear away at more complex prey.
     Instead of scientific feedback, I get severe criticism and now a stony
silence. If I am so obviously wrong, why can't the experts write a paragraph
or two presenting some evidence that clearly refutes my "hypothesis"?   Why
do I have to get frustrated and "pushy" to get even a little feedback?
Perhaps I *am* a glutton for punishment (as some have goodnaturedly
suggested), and if the "kill the messenger" trend continues, perhaps I will
have to start spending my spare time taking up golf or doing crossword
puzzles.
      It just doesn't make any sense to me that the first gastropods were
so-called "archaeogastropods" with complex radulae (for complex prey),
full-blown torsion, and a streptoneurous nervous system.  If only it were a
more simple case of "cause and effect", like Helicobacter causing stomach
ulcers (but even that hypothesis was scoffed at, sometimes ridiculed, for
many years).  I guess I've got spoiled by how dinosaur science is being done
today, where new ideas are rapidly evaluated, sometimes in a matter of days.
  Their approach to cladistic analysis is so much more efficient, as open
discussion has begun to far more quickly reveals miscodings and
misinterpretations.  Perhaps that is  something malacology and other
disciplines might want to emulate.  Maybe we could get some "timely"
reevaluation of some "confirmed" synapomorphies (like "radula lost") in that
manner.
          ----  Sincerely,
                      Ken Kinman


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