Message 2004-02-0001: Re: a comment on ancestors

Wed, 04 Feb 2004 10:15:31 +0300

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Date: Wed, 04 Feb 2004 10:15:31 +0300
From: "Igor Ya. Pavlinov" <igor_pavlinov@zmmu.msu.ru>
To: PhyloCode <phylocode@ouvaxa.cats.ohiou.edu>
Subject: Re: a comment on ancestors

Well, then we have to go to the theory of definitions to look if reference
to something which is not presumed (because of impossibility) to explore is
the definition at all. If you define a taxon by a character or by a type you
mean that it is possible to allocate any newly discovered item to that taxon
by observing respective character or type. The present PhyloCode definition
of taxon membership presumes that in order to allocate a new item to one or
another monophyletic group in existing classification, one has to run
complete cladistic analysis in which all members of those groups + new item
are to be included. But what to do if those groups were recognized, say, by
DNA analysis and no DNA data are vailable for the new item?
It seems to me that theoretical and empirical definitions of taxon
membership are mixed in the PhyloCode.
At any rate, I think that PhyloCode definition of taxon membership is to be
more seriuosly investigated by some logicians.
Igor

----- Original Message -----
From: Philip Cantino <cantino@ohiou.edu>
To: Igor Ya. Pavlinov <igor_pavlinov@zmmu.msu.ru>
Sent: Tuesday, February 03, 2004 9:57 PM
Subject: Re: a comment on ancestors


> Dear Dr. Pavlinov,
>
> Some of the phylogenetic definitions used in the PhyloCode (see Note
> 9.4.1) refer to "the most recent common ancestor" but one does not
> have to be able to recognize the ancestor in order to use the
> definition.  Furthermore, each definition type has at least one
> recommended wording that does not refer to ancestors (e.g., the least
> inclusive clade containing A and B).  Again, I refer you to Note
> 9.4.1.
>
> Sincerely,
> Phil Cantino
>
>
> >I'd like to call your attention to the following.
> >
> >From the vary beginning of claditstics, the concept of the
> >species-as-ancestor was acknowledged as non-operational one, as
> >there is no practical criteria for recognizing a particular species
> >as the ancestor of a particular monophyletic group. That is why
> >concept of sister group is more consistent with initial epistemology
> >conditions of the new phylogenetics. I wonder if the PhyloCode in
> >its present version is consistent and operational in respect to
> >definition of taxa and their names by refernce to
> >species-as-ancestor.
> >
> >Thank you.
> >- - -
> >Dr. Igor Ya. Pavlinov
> >Chief, Division of Mammals
> >Zoological Museum
> >Moscow M.V.Lomonosov State University
> >ul. Bol. Nikitskya, 6
> >125009 Moscow
> >Russia
> >Tel.: (095)2032940
> >Fax: (095)2032717
> >E-mail: <mailto:igor_pavlinov@zmmu.msu.ru>igor_pavlinov@zmmu.msu.ru
> >
>
>
> --
> Philip D. Cantino
> Professor and Associate Chair
> Department of Environmental and Plant Biology
> Ohio University
> Athens, OH 45701-2979
> U.S.A.
>
> Phone: (740) 593-1128; 593-1126
> Fax: (740) 593-1130
> e-mail: cantino@ohio.edu



  

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