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Re: Non-serpentine lacertids (was RE:WHAT'S GOING ON?)



In a message dated 7/3/00 1:00:37 PM EST, cbrochu@fmnh.org writes:

<< It is never natural to remove a descendent from a supraspecific taxon. >>

I'd like to see a good reason for this opinion. It lies at the heart of the 
differences between cladistic taxonomies and non-cladistic taxonomies and the 
disputes between their respective adherent taxonomists. To me, a "natural" 
group must include its common ancestor but need not include all the 
descendant subgroups of this common ancestor (though it usually does). The 
criteria for removing such a subgroup into an independent taxon are 
qualitatively no different from the criteria that distinguish one species 
from another. There is no difference in phyletic information content between 
the statements "birds are dinosaurs" and "birds descended from dinosaurs." 
Why should one be preferred and the other rejected?