Message 2004-02-0020: Re: RE: a comment on ancestor

Mon, 09 Feb 2004 10:30:56 +0300

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Date: Mon, 09 Feb 2004 10:30:56 +0300
From: "Igor Ya. Pavlinov" <>
To: PhyloCode <>
Subject: Re: RE: a comment on ancestor

I agree with Gerry that it is to be explicetly stated in the Phylocode
preamble how names of non-holophyletic groups are treated by it - are they
available and valid or not. And in some of the articles special
consideration should be paid to not rare (rather, near to unversal)
situations when a group is treated as holophyletic in one hypothesis and as
paraphyletic in another (Pinnipedia is good an example). All this is needed
to make more clear what used to happen with the name in situation when the
name-bearing taxon losts its holophyletic status.

What seems to be also important, is treatements of procedures by which
phylogenetic hypotheses are elaborated. For me, it is clear that trees
obtained by middle-point rooting or UPGMA procedures are methodologically
phenograms rather than cladograms. So, as a clade is thought to be validly
recognized within a particular phylogenetic hypothesis only, then what are
criteria of validity of the hypothesis itself? Surely consideration of such
a topic within the Phylocode will cause many objections, but at least some
indication that not all trees are phylogenetic ones, although are called so,
would be no less desirable than undication of criteria of publication

At last (or at first), it would be good to state (also explicetly) how the
Phylocode relates the International Code: does a part of it (then how to
cooperate with the Comission?) or something "parallel". Such a
clarifications would be important in respect to nomenclature stability.


> >>> "Moore, Gerry" <> - 2/6/04 8:43 AM >>>
> I don't agree that the PhyloCode could be used to give explicit
> definitions to names of non-monophyletic taxa. This assertion has also
> found it way in print by Kevin and Phil (Taxon 50: 821-826. 2001):
> "First it should be noted that although the PhyloCode is designed to
> name clades, it does not expressly prohibit the naming of paraphyletic
> groups."
> The first article (1.1) in the PhyloCode "only clade names are governed
> by this code." And the next article (2.1) defines clade as "an ancestor
> and all of its descendents."  Given this, any name given a definition
> that identifies a non-monophyletic group would have no standing under
> the PhyloCode. Arts. 11.9, 11.10 also make it clear that names that do
> not identify a clade in the context of a given phylogeny are not to be
> used.
> The PhyloCode may not expressly prohibit the naming of non-monophyletic
> taxa but it is pretty clear they are prohibited nonetheless.  A code
> that uses explicit definitions could be written so that it permits the
> naming of non-monophyletic taxa but the PhyloCode is not written this
> way.
> Gerry Moore


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