[Taxacom] cladistic analysis of characters with variable presence

Sergio Vargas sevragorgia at gmail.com
Thu Jul 14 13:21:10 CDT 2011



Hi,

Isn't this a simple case in which one character is polymorphic in one or more species?

if so, there are plenty of ways to code polymorphic characters. Check the following articles:

Wiens, J., 1995. Polymorphic characters in phylogenetic systematics. Syst Biol 44, 482-500.

Wiens, J., 1999. Polymorphism in systematics and comparative biology. Annu Rev Ecol Syst 30, 327-362.

sergio


A recent paper on primate anatomy and phylogeny did a cladistic analysis
for characters where the derived character states were variable in the
population of each species. Thus, character A might have a derived state
that occurred only in the in-group, but in 20% of individuals for taxon
1, 50% of individuals of taxon 2, and 90% of taxon 3. These taxa were
coded such that species with a higher proportion of individuals with the
derived state were coded as being more derived.



My question is whether the varying proportions of a character state in
different species can be considered to represent a phylogenetic signal -
i.e. that they are a constant of the taxa involved and invariable over
time so those proportions represent a shared derived state. Intuitively
I think this would not be cladistically valid, but rather an artifact of
population dynamics at any one time. Someone must (?) have commented on
this in the literature - in which case I would be very interested to
know those views.



-- 
Sergio Vargas R., M.Sc.
Molecular Geo- and Palaeobiology Lab.
Dept. of Geo-&  Environmental Sciences, Palaeontology and Geobiology
LMU M√ľnchen
Richard-Wagner Str. 10
80333 Munich, Germany
tel. +49 89 2180 17929
s.vargas at lrz.uni-muenchen.de
sergio.vargasr at ecci.ucr.ac.cr

check my webpage:
https://sites.google.com/site/marinemolecularevolution/

check my research ID:
http://www.researcherid.com/rid/A-5678-2011





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