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Re: seeking clarification on the cladism debate (RE: hidden "cladistic" ranks)
If I've counted correctly, this should be my last (seventh) message for
On Thu, 18 Oct 2001, David Elliott wrote:
> >For one thing, certain traditionally paraphyletic groups, converted to
> >clades, would contain other taxa of equal or even greater rank. Ordo
> >Saurischia, for example, would include Classis Aves. You could reassign
> >ranks, but would find very soon that you had run out of space.
> Has the idea of setting points along phylogenies where the ranks are
> "reset" been discussed?
That would undermine the entire concept of an absolute rank. A taxon with
a lower level rank (e.g. Ordo Saurischia) should never include a taxon
with a higher level rank (e.g. Classis Aves). If it can, then the ranks
are rendered even more meaningless than before.
Furthermore, picking these points would be an entirely subjective
practice, without any scientific principle to back it up.
T. MICHAEL KEESEY
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