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Genetics and Morphology Collide



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Have you seen the article in Mature, Vol. 379, Jan. 25, 1996?  Phylogenetic
position of the order Lagomorpha by Graur, et. al. Based on an impressive 88
protein sequences, lagomorphs clade with primates, not rodents as morph
characters would show.

Here is a partial quote from that article: "...morphological
'synapomorphies'previously used to cluster rodents and lagomorphs into
Glires, may actually represent symplesiomorphies or homoplasies that are of
no phylogenetic value."

I think that molecular data is going to win out.  This thinking correlates
with Stephen Gould's theories.  A very few character state changes can
result in profound morphological differences rendering those differences
insignificant compared to overall evolution in an organisms' genome.

So perhaps dinos have a mammalian-like physiology with a reptilian-like or
other type of morphology.  Perhaps there is an unexpected mix of character
states that may be the root of confusion as to the exact relationships
between dinos and birds and reptiles and mammals.

OK, so I am opening another can of worms.  There is more to an organism than
just bones and teeth.  I don't mean to offend, and I know I have made plenty
of enemies in this field, but I just want to emphasize the need for
molecular data in addition to what is already known, but expect that data to
contradict the morphological data in many cases.

Chip Pretzman
Dept. of Molecular Genetics
Laboratory of Evolutionary Genetics
The Ohio State University
484 W. 12th Ave.
Col., OH 43210
cpretzma@magnus.acs.ohio-state.edu
1-614-848-5056