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Date: Sun, 22 Apr 2001 00:10:11 -0700 (PDT)
From: "Jaime A. Headden" <qilongia@yahoo.com>
To: phylocode@ouvaxa.cats.ohiou.edu
Cc: tmk@dinosauricon.com
Subject: Re: Vermes
Mike Keesey wrote: <Just thinking ... wouldn't this recommend that _Synapsida_ and _Therapsida_ be called _Theropsida_ and _Neotheropsida_, respectively?> They would have to explicitly state this in the definitions. We can preserve Amphibia, Synapsida, etc.. However, as I've stated before, paraphyletic taxa are not useful without explicit philosophy on their existence: they are not evolutionarily unique groups, in the sense of a stem or node-based taxon. They are united by their superficiality, not biological actuality, even if they are biologically actually a group. It's the philosophy that works for vulger terminology, and that's where I feel paraphyeletic names should stay. Amphibia and Synapsida can still be defined as nodes or stems, but I think the latter _has_ been defined; I'm not sure about the former. <Of course, membership isn't really fixed into a phylogenetic definition, except for the specifiers, and there are already rules and recommendations to make sure that the specifiers, at least, are appropriate. But what if someone defines a group so that it corresponds well to the traditional usage under presently understood phylogenies, but then it changes drastically under a new phylogeny? How would the proposed recommendation work in that situation? Even worse, what if there are two main schools of though on the phylogeny, wherein the clade matched the traditional taxon unde one school of thinking, while it differed drastically according to the other school? This is why I have doubts about such a recommendation.> And when one makes a distinction between the Mayrian school and the Linnaean school, and one tries to incorporate the system in the Cuvierian school (etc.), one runs into roadblocks, and people will scream and curse the name for all the world to hear. Find a singular philosophy, one that explains the world by _most_ criteria, and add specific flexibility clauses to the inflexible, so that certain definitions, seemingly to be so inherently wrong, can be reformulated. There is a petition process clause in the PhyloCode, as Cantino has said here, and in the PhyloCode itself. A change in the terminology can be affected by making an argument against an existing definition more than the commonly-heard pedantic "My definition is better than your definition". [I'm not quoting here.] A basic statement of philosophy proceeds the articles of the PhyloCode. The BioCode is Linnaean on its face, thus typological, so we are pretty clear about philosophy. A prescription concerning paraphyletic taxa might be neccesary, so that subsequent workers can formulate definitions in reflection of this, so that they can explicitly include all descendants, or specifically not include one or two, or more. What say you all? Jaime A. Headden "I've got Irish blood, and I'm not afraid to use it!" __________________________________________________ Do You Yahoo!? Yahoo! Auctions - buy the things you want at great prices http://auctions.yahoo.com/