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

[Barry Roth]

The choices that John describes making depend on certain assumptions about the course of evolution.  In this case, it seems to be that "common equals primitive."  "Progression from simple to complex" is another such assumption I have seen used, and "morpho-physiological progress," "intensification of function," and "increasing level of differentiation" are others.  But allowing preferences like these stacks the deck (forgive me if that is a uniquely English-language card playing expression) before the analysis is allowed to run.

Barry Roth

----- Forwarded Message -----
From: John Grehan <jgrehan at sciencebuff.org>
To: taxacom at mailman.nhm.ku.edu
Sent: Friday, August 12, 2011 6:39 AM
Subject: Re: [Taxacom] clique analysis in texbooks (was: Evolution of, human-ape relationships...)


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

Bet lost - yes I do not include equivocal traits (i.e. traits that are
not uniquely shared among members of the ingroup or are at least nearly
so). That is quite evidence from the orangutan analysis. 

I can be criticized for some subjective discretionary bias with the
caveat about nearly so, but in such instances the characters are
specified and the analysis can be independently run without them. As
case in point is the thick molar enamel shared between humans and
orangutans. This feature occurs in a couple of NW and OW monkeys (and on
teeth that are structurally different). We considered this sufficiently
rare to view the thick enamel of humans and orangutans as a derived
condition. Of course if one were examining the relationships among all
species of monkey, gibbon, and large bodied hominoid, then one could use
the thick enamel character for all those taxa where it occurs relative
to an outgroup of thin enameled species (such as the prosimians).


John Grehan



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