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RE: Kileskus and Proceratosauridae
David Marjanovic wrote:
<What do you mean by "singular"? Does "a singular structure" mean
"the same taxon"?>
A set, rather, or any formalized definition of a group of OTU's. Group, Set,
Taxon, etc. However, Structure in this case is a reference to the variations of
portions of a tree which can be set aside as taxa.
On to the greater point.
The definitions for Monophyletic and Clade in the Phylocode glossary at
http://www.ohio.edu/phylocode/glossary.html are virtually synonymous, which
makes them virtual tautologies. Note that when I used that term, when Mike
replied he passed the use of the term without comment, and when you replied to
him to elaborate on his response to me, you also quoted it and passed on it, so
the use of theterm being at issue is interesting. In accordance with the
definition of a tautology ("needless repetition of an idea, esp. in words other
than those of the
immediate context, without imparting additional force or clearness, as
in “widow woman.” see http://dictionary.reference.com/browse/tautology?r=75),
one would argue that the phrase "monophyletic clade" is not in the strictest
sense a tautology, but that was the word that Averianov et al used nonetheless
(I swear I didn't make it up!). But they are redundant, and it makes me wonder
whether the term "clade" is not more useful than the definition provided
This does interest me further, though. What are the original historical uses
of the phrase "clade" that renders classic forms such as Reptilia sensu
Linnaeus NOT monophyletic and therefore not clades? I.E., why does "Clade"
render to us a definition that is synonymous with "monophyletic," and also why
are we not also using "holophyletic"?
Jaime A. Headden
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