DePhylocode: Light, not heat?
kinman at HOTMAIL.COM
Fri Mar 8 13:03:57 CST 2002
I too would be interested in hearing more details about Nixon's talk (I
am so far behind on keeping up with the botanical literature). Just
wondering if he thinks the "core eudicots" are still a holophyletic group,
but that maybe the stem eudicots arose separately (either convergently or in
parallel). If there are two parallel groups of eudicots, I would guess they
are still fairly closely related, and that the addition of a group or two of
"non-eudicots" might render it holophyletic again. Two groups actually
converging on the eudicot condition would be rather surprising.
In any case, such things do point out how unstable purely cladistic
hierarchies can be. I personally love seeing the "yahoos" (and "non-yahoos"
too) coming out with lots of new cladograms (I love cladograms and the more
the better). However, I hate seeing them being automatically transformed
into new formal names and classifications. This is increasingly apparent in
theropod systematics, with Sereno, Gauthier, Holtz, and others playing
dueling cladograms that produce clashing nomenclatures (and some clades are
getting named several times over, which is especially bad when they turn out
to be paraphyletic or even polyphyletic).
I suspect that the pattern cladists are probably horrified that the
phylocode is so clearly exposing the weaknesses in ALL purely cladistic
classifications. This would only add to their irritation due to other
philosophical differences within the cladistics community.
Just about the only thing that unites all these strict cladists is the
belief that formal paraphyly is always bad, which naturally alienates them
all from those who like using cladistic analysis as a tool (the non-strict
"cladists" or as I would prefer to say "Ashlockian cladists"). Strict
cladists claim that we are not cladists at all. So the word cladist is now
pretty much meaningless without qualification.
>From: Richard Jensen <rjensen at SAINTMARYS.EDU>
>Reply-To: Richard Jensen <rjensen at SAINTMARYS.EDU>
>To: TAXACOM at USOBI.ORG
>Subject: Re: DePhylocode: Light, not heat?
>Date: Fri, 8 Mar 2002 08:11:28 -0800
>Ken Kinman wrote:
> > The clade "eudicots" is an excellent example of how most such
> > *should* be named--- informally. This indeed does work very well. I
>recognized the "eudicot" clade in my 1994 classification.
>Last August, at the Botany 2001 meetings in Albuquerque, Kevin Nixon, in a
>wonderfully presented critique of Phylocode, demonstrated that the
>"eudicots" are based on a smattering of evidence that almost assuredly will
>survive more careful scrutiny. I don't have all the details, but one of
>points was that such ephemeral taxa are one excellent reason for not
>Perhaps some out there have a better recollection than I of what Kevin
>Richard J. Jensen TEL: 219-284-4674
>Department of Biology FAX: 219-284-4716
>Saint Mary's College E-mail: rjensen at saintmarys.edu
>Notre Dame, IN 46556 http://www.saintmarys.edu/~rjensen
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