Info req.: molecules/morphology
B. J. Tindall
bti at DSMZ.DE
Tue Jun 27 08:40:15 CDT 2000
Is this question just related to zoology, or do you want to diverge into
other groups? There are quite a few hidden problems in the question, which
include whether molecular trees are reconstructed/estimated by similarity
matrix, parsimony, or maximum likelihood methods (all can give rather
different topologies and of course within any one class of programs each
algorithm many also give slightly different results). Another problem is
the discussion which often surfaces relating to the reliability of none
"molecular" data (i.e. are sequence data more reliable than phenotypic data).
Certainly one of the problems which is surfacing at present is the problem
associated with the increasing amount of sequence data. While in the
"early" days one may have compared an ant and an ape by sequence data and
found them to be different, one gets into more difficulties when you try to
resolve the topology of a set of organisms where the branching points all
lie close together. This causes problems of a) determining absolute order
of branching and b) does not always allow one to assign organisms
unambiguously to one clade or another. I assume that this is one of the
problems you are alluding to.
Brian
>Can anyone suggest recent papers that address in any detail the idea that
>clades that emerge in phylogenetic analyses of molecular data require
>morphological or other non-molecular synapomorphies before it is practical
>to recognize them formally? I am particularly interested in commentary or
>theoretical papers on this topic, rather than primary research papers in
>which the topic had to be dealt with, though anything would be helpful.
>
>Thank you for your help.
>
>Thomas G. Lammers, Ph.D.
>
>Assistant Professor and Curator of the Herbarium (OSH)
>Department of Biology and Microbiology
>University of Wisconsin Oshkosh
>Oshkosh, Wisconsin 54901-8640 USA
>
>e-mail: lammers at uwosh.edu
>phone: 920-424-7085
>fax: 920-424-1101
>
>Plant systematics; classification, nomenclature, evolution, and
>biogeography of the Campanulaceae s. lat.
>-----------------------------------------------------------
>"Today's mighty oak is yesterday's nut that stood his ground."
> -- Anonymous
>
>
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