D.Walter at MAILBOX.UQ.EDU.AU
Wed Feb 6 10:14:24 CST 2002
Thanks very much for the summary of plant phylogeny. It's always a
pleasant surprise when Taxacom yields something interesting.
>To me, the whole purpose of biological classification is to provide a
>framework for understanding life, and I find that lineage groups do that
>quite nicely. Paraphyletic (and even polyphyletic) groups are part of our
>heritage as biologists, and can't be ignored. But they don't have to be
I agree with the basic premise, but it seems obvious to me that we all do
perpetuate paraphyletic groups to one degree or another by using the
traditional groups we now have reason to believe are flawed. We do it
every day. So, we all act eclectically, however unwillingly, and much of
the contentious arguments in this stream has no logical basis. We need
paraphyletic groups until monophyletic alternatives are generally
accepted. For those few who prefer paraphyletic groups, well, good luck
with your referees.
>... There is the clade usually called "eudicots" that are those
>dicots with tricolpate or tricolpate-derived pollen, as well as a bunch of
>other apomorphies both morphological and molecular. They and the monocots
>form two robust, well-marked groups ...
>In a sense, the flowering plants that aren't eudicots or monocots are
>"ground trash" (figuratively) under the two great branches. This is not an
>uncommon feature of well-marked clades ...
>This is a common theme in evolution: some lineages are wildly
>successful and others aren't.
In parallel, Euoribatida is the solution proposed for a similar mite
problem (and an inclusive clade, the Sarcoptiformes, that includes 'ground
trash' and more derived lineages). Unfortuantely, no one seems in a hurry
to adopt the new terms, although the supporting data seems clear. An
interesting aspect of the sarcoptiform 'ground trash' is that many are clones.
Cheers from Oz,
Dr David Evans Walter
Department of Zoology & Entomology
The University of Queensland
St Lucia, QLD 4072 Australia
fax: (61) 7-3365-1655
The University of Queensland Remote Program in Entomology
Cooperative Reseach Centre for Tropical Plant Protection
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