Australopithecus and orangutans

[Julian Humphries]

John Grehan wrote:

>
> My understanding and practice in morphology is to designate apomorphic
> characters.

That is simply wrong.  The majority of workers (morphological or
otherwise) do not a priori designate a character state (not character),
as apomorphic.  How could you? Unless you know the truth ahead of time
the characterization of a state as a synapomorphy of two taxa is a
result of analysis, computer driven or otherwise.  Workers designate
outgroups (and their states) as pleisiomorphic and let the chips fall
where they may. Having the same state as the outgroup might be indicate
a retained pleisiomorphy, or might be an apomophy at some level of the
tree (see below).  There is absolutely no fundamental difference between
molecules and morphology as to the assessment of "shared derived
characters."

In fact, the situation is made more complex due to optimization of
character state evolution (equally parsimonious solutions, even on the
same tree, may yield multiple distinct sets of shared derived
characters, thus synapomorphies may depend on which optimization
strategy you adopt.)  Thus, a state appearing in an outgroup and an
ingroup may be a retained pleisiomorphy, or a novelty, depending on
optimization. Characters with homoplasy, may, at some level, still
diagnose major clades.  All of this complexity is why that "computer
contrived analysis" (this is the kind of word baiting typical of
Kinman), is so necessary.

--
Julian Humphries
DigiMorph.Org
Geological Sciences
University of Texas at Austin
Austin, TX 78712
512-471-3275