[Taxacom] Endless Subject

Richard Zander Richard.Zander at mobot.org
Mon Apr 6 13:05:10 CDT 2009

Well, how about this: Don Colless suggested that reference to a
cladogram clarifies a classification. Perhaps a classification that
includes evolutionary information about both sister-group and
ancestor-descendant relationships can be disambiguated with reference to
both a cladogram (or phylogram) and a taxon tree. 

A taxon tree, for those born into the world swaddled in holophyly, is a
diagram of taxa evolving from other taxa, a kind of Besseyan cactus.
Examples are Darwin's original Tree of Life (p. 95 in the paperback),
the famous tree of horse evolution (Strickberger (1990), and my own
Pottiaceae taxon tree (see

Thus, although Hull 1979 was right (thanks, Ken K.) that both geneology
and divergence cannot be incorporated into a classification is such a
way that both are retrievable, both are flagged in a (maximally
informative) evolutionary taxonomy classfication as evolutionarily
important, and the distinctions are maintained as retrievable in 1.
discussions and the literature, and 2. diagrams, namely cladograms and
taxon trees.

Richard H. Zander 
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Missouri Botanical Garden
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richard.zander at mobot.org
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-----Original Message-----
From: taxacom-bounces at mailman.nhm.ku.edu
[mailto:taxacom-bounces at mailman.nhm.ku.edu] On Behalf Of Curtis Clark
Sent: Saturday, April 04, 2009 10:47 AM
Subject: Re: [Taxacom] Endless Subject
A classification that mixes sister-group, ancestor-descendant, and
phenetic information without clarifying where they are used is
*minimally* predictive, since any grouping can and will be misconstrued.

Curtis Clark                  http://www.csupomona.edu/~jcclark/

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