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Re: Untested assumptions (was Re: segnosaurs)

In a message dated 97-08-01 23:07:11 EDT, th81@umail.umd.edu (Thomas R.
Holtz, Jr.) writes:

<< Duke University zoologists M.R. Sanchez-Villagra and B.A. Williams have
 actually bothered to TEST whether cranial, dental, or postcranial characters
 are more homoplastic.  They examined 41 published data sets of various
 mammalian taxa, from within-genus studies to studies including most
 mammalian orders.  They found that there was no (count them, no)
 statistically significant differences between the amount of homoplasy found
 in skull characters, in teeth, or in the postcranium.  Their main
 conclusion: "Our analysis of existing data suggest that characters from the
 dentition, the cranium, or the postcranium are in general equally
 homoplastic and none should be dismissed or disregarded in phylogenetic
 analyses without a close analysis of the data."
 So, could we PLEASE leave our untested assumptions aside? >>

What this means, therefore, is that any part of a mammalian skeleton is as
diagnostic as any other part. This is certainly not true of dinosaurs. Or,
perhaps, not YET true of dinosaurs.