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[Hubert Turner]

At 11:10:23 +0200, PIETER WINTER wrote:
>The "different nature" of paraphyly at different levels is presented as
>some sort of obvious truth. I must have missed something. Can anyone
>elaborate on this? Surely they are both the results of the same process,
>separated only by time and extinction long after the event?

Mono-, para-, and polyphyletic are relative clauses: One has to clarify
what kind of sets one is talking about: of species (clades?), of lineages
(sets of individuals amongst which the relationships are tokogenetic, not
phylogenetic), or of individual specimens. Above the species level it is
usually understood that the clause refers to species: A clade is [a]
monophyletic [set of species] if it includes one particular species and all
its descendant species. However, at the species level it should be made
clear what one is talking about: a set of lineages or of e.g. specimens.
Hubert Turner


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Dr. Hubert Turner
EEW, Sect. Theoretical Biology & Phylogenetics
PO Box 9516, 2300 RA  Leiden, The Netherlands
Visiting address: Van der Klaauw Laboratory, Kaiserstraat 63, Leiden
Phone: +31-71-5274904    Fax: +31-71-5274900
E-mail: turner at rulsfb.leidenuniv.nl
WWW: http://wwwbio.leidenuniv.nl/~turner/index.html
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