[Taxacom] Felsenstein lecture available on-line

John Grehan jgrehan at sciencebuff.org
Thu Dec 4 20:29:12 CST 2008

-----Original Message-----
From: taxacom-bounces at mailman.nhm.ku.edu
[mailto:taxacom-bounces at mailman.nhm.ku.edu] On Behalf Of Dr. David
Sent: Thursday, December 04, 2008 1:31 PM
> Occasional convergence, reversion, orotherwise misleading results are
likely to occur with any character, 
> molecular or morphological. 

Its reassuring to see this kind of statement.

> Molecular data are especially vulnerable to errors from
misidentification, contamination, etc., which 
> must be in mind if an unusual result appears.  

Cheers, cheers. That's more than most molecular systematists are willing
to admit. But what is an 'unusual result'? Perhaps the chimpanzee-human
molecular similarity is the unusual result given the lack of
morphological corroboration.

> Aligning or at least checking alignments by hand is a valuable way to
catch anomalous sequences, 
> whereas feeding raw sequences into an analysis that internalizes the
homology model makes anomalous 
> sequences easy to overlook.  

In practice the trouble with checking alignments by hand is that no one
(at least of the papers I have seen) bothers to specify how they make
their personal alignment decisions, just give the results. So there is
no predictability to their hand method. Voodoo systematics rears its
head again.

John Grehan

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