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Date: Tue, 26 Feb 2002 14:16:27 +0000 (GMT)
From: Mike Taylor <mike@tecc.co.uk>
To: laurin@ccr.jussieu.fr
Cc: PhyloCode@ouvaxa.cats.ohiou.edu, phyloadvisors@ouvaxa.cats.ohiou.edu
Subject: Re: Crown clade definitions (was: Re: interesting style of definition)
> Date: Tue, 26 Feb 2002 10:23:20 +0100 > From: Michel Laurin <laurin@ccr.jussieu.fr> > > As to the question of how people use the term "related", I > agree with Harold that to my knowledge, all authors who will care to > formulate phylogenetic definitions use this term in the cladistic > sense. I even think that most cladists (even those who don't accept > phylogenetic nomenclature) use it in this sense. I also agree with > the comment made by Jonathan that there is no unique solution to the > question of phenetic distance, and the discovery of new intermediate > forms would likely require changing classifications made using this > criterion. I'm sure no-one (or at least no-one on this list :-) disagrees that the only objective meaning of "more closely related" is "sharing a more recent common ancestor". But there's still a problem, and it arises from the fact that obstacles which the PhyloCode faces are not so much technical as they are problems of evangelism. If we are serious about having the PhyloCode widely adopted, it surely behoves us to ensure that our terminology is as precise and unambiguous as possible even from the perspective of someone not steeped in phylogenetic semantics. Someone coming from an extreme Linnaean tradition, for example. For that reason, I agree with Mike Keesey that it's better to use explicit terms like "recent common ancestor" even if _we_ all understand simpler terms like "related" to mean the same thing. _/|_ _______________________________________________________________ /o ) \/ Mike Taylor <mike@miketaylor.org.uk> www.miketaylor.org.uk )_v__/\ "Personally, I don't think its sexual dimorphism. I'm all for it, but not in this case" - Tracy L. Ford.