[Taxacom] clique analysis in texbooks (was: Evolution of, human-ape relationships...)

[Richard Zander]

John I think is combining (1) cladistic analysis with (2) scientific
intuition and discursive reasoning, which I admit is combining (1)
gravel and (2) oranges. He discards equivocal traits because it is
nonsense to use them, I think. That seems pretty good justification. 

I bet, however, one cannot get a yes or no about this from John, bless
him.

IMO, morphological cladograms, if you fiddle with them enough, can make
a fine natural key. This would be good guidance to evolutionary
relationships, and one might expect such morphological relationships to
be different from the relationships in molecular trees for reasons I've
gone on and on about. 

 

* * * * * * * * * * * *
Richard H. Zander
Missouri Botanical Garden, PO Box 299, St. Louis, MO 63166-0299 USA  
Web sites: http://www.mobot.org/plantscience/resbot/ and
http://www.mobot.org/plantscience/bfna/bfnamenu.htm
Modern Evolutionary Systematics Web site:
http://www.mobot.org/plantscience/resbot/21EvSy.htm


-----Original Message-----
From: taxacom-bounces at mailman.nhm.ku.edu
[mailto:taxacom-bounces at mailman.nhm.ku.edu] On Behalf Of Sergio Vargas
Sent: Thursday, August 11, 2011 3:42 PM
To: taxacom at mailman.nhm.ku.edu; pierre.deleporte at univ-rennes1.fr
Subject: [Taxacom] clique analysis in texbooks (was: Evolution
of,human-ape relationships...)

[snip]
If I have understood everything so far, John Grehan will discard such a
character because it is not exclusively derived... (I forget the exact
phrase), but I find no recommendation to eliminate such a characters in
the book (above) or in the literature; and the book is about cladism! So
instead of compatibility analysis I would say John Grehan restricts the
character matrix to characters were the polarity can be decisively
determined and discards characters that could yield equivocal polarity
reconstructions. I cannot remember of any published justification for
this, and I am concerned about the bias potentially introduced by this
method.

sergio



-- 
Sergio Vargas R., M.Sc.