genetic vs morphological trace of phylogeny

pierre deleporte pierre.deleporte at UNIV-RENNES1.FR
Mon Apr 5 15:06:56 CDT 2004

At 22:07 03/04/2004 +1200, John Grehan wrote :
>(...) Unfortunately (perhaps) there is no
>recipe for making a predetermined choice when DNA sequence similarities and
>morphological synapomorphies are incongruent.

But fortunately, no predetermined choice is needed. The current practice 
is, not to use only morphological similarities (which are not in themselves 
totally congruent) or only molecular ones (themeselves not totally 
congruent either), but to combine all available, and potentially relevant, 
information (molecular data sets + morphological ones), which you still 
seem highly reluctant to do in practice.
This can be done through all kinds of analyses: cladistic under various 
possible weighting schemes, and also maximum likelihood under a variety of 
models (a few recent papers deal with the last procedure)...

There are lasting problems as for which models of character evolution 
should be implemented, both for morphoilogy or molecules (see many other 
threads), but I never read a convincing argument that some potential source 
of phylogenetic information should be completely discarded.
Ignoring molecular information for the Pongo question is undefendable. You 
can easily join with a molecularist and perform a complete analysis of all 
available potential evidence. If you want to. I think this would be a more 
adequate presentation of the present state of phylogenetics than 
considering morphological evidence in isolation.


>John Grehan

Pierre Deleporte
CNRS UMR 6552 - Station Biologique de Paimpont
F-35380 Paimpont   FRANCE
Téléphone : 02 99 61 81 66
Télécopie : 02 99 61 81 88

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