[Taxacom] quote of the week

John Grehan jgrehan at sciencebuff.org
Wed Mar 26 07:45:44 CDT 2008

> -----Original Message-----
> From: taxacom-bounces at mailman.nhm.ku.edu [mailto:taxacom-
> bounces at mailman.nhm.ku.edu] On Behalf Of Pierre Deleporte

> > I had mentioned on this list that I am currently working on a
> > morphological analysis.
> maybe, 

Or maybe not?

but you are accusing molecules all the time (while not even
> trying to analyse them, and this is the problem)

What's the problem? All I am saying is that morphology gives reason to
question the assumptions that molecular results are always necessarily
correct, and there are a variety of possibilities about the nature of
the molecular data that could explain why.

> so it seems that you have found a cladistic analysis program at

What is the point of this sarcasm?

> so you will hurry and treat the molecular data the same way as you are
> treating morphological ones?...

No, that has already been done by innumerable molecular systematists.
Why repeat their analyses when I am not questioning that they got what
they got. What I do question is whether the molecular result trumps the
morphological result.

> this is precisely why we use programs... surprising, isn't it?   ;-)

Again, I am not sure of your sarcasm. I have never objected to the use
of computer programs. I think you are confusing my objections to
molecular results with objecting to computer programs. 

> now, are you certain that you are using your program according to your
> self-claimed criteria for 'cladisic' analysis? I don't think that
> default options in PAUP will search for a clique of 'uniquely derived'
> characters only, 

Sorry, I don't understand this. I have character states that are
uniquely derived for the ingroup and that are variously shared by taxa
within my ingroup. I use PAUP to decide which hypothesis of
relationships within the ingroup is best supported. That's what everyone
else does.

i.e. weighting "zero" partially homoplastic characters,
> as your unpublished algorithm seems to require;  this would
> implementing specific options of ad hoc programs...

Again, you seem to be imputing something about the nature of the
analysis. If there is a tragic flaw that others (including systematists
who have looked at the draft)have not seen then you will be able to
point them out in due course.

Nothing contradictory at all. The program determines the level of
support for the best corroborated set of character relationships for the
ingroup taxa.

John Grehan

More information about the Taxacom mailing list