Message 2001-09-0012: Re: Apomorphy-based definitions

Mon, 27 Aug 2001 10:10:26 -0300 (ADT)

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Date: Mon, 27 Aug 2001 10:10:26 -0300 (ADT)
From: "Alastair G. B. Simpson" <simpson@hades.biochem.dal.ca>
To: "Jonathan R. Wagner" <jonathan.r.wagner@mail.utexas.edu>
Cc: PhyloCode mailing list <phylocode@ouvaxa.cats.ohiou.edu>
Subject: Re: Apomorphy-based definitions

On Sun, 26 Aug 2001, Jonathan R. Wagner wrote:

>     Actually, if species are considered to be individuals (a divisive
> suggestion, I know), than an entire species may be considered to be
> "ancestral" to another, just as an entire organism is ancestral to another.
> If this is held to be the case, the "most recent common ancestor" refers to
> a SPECIES, not an organism, and the problem you discuss vanishes.

Well, you move the problem to being one of determining when
one species transforms into the next one: However one would guess that
there is no perfect way defining that either.
(Needless to say, some level of fuzziness will creep into any system
of taxon definition; Node- Stem- and Apomorphy-based definitions do a
great job of minimising it!) 

Alastair Simpson


  

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