Well said John,



I personally think there are two waring issues in this argument that get intermingled. The need to be teased apart because they really are two separate issues independant of each other.



1. is the issue of paraphyly and I agree John that there is no room for paraphyly and that it goes against the pricipals of Evolution by decent as well as the the principals of systematics by Mayr and others.



2. The issues of nomenclatural stability, ie splitting versus lumping.



A third issue creeps in and that is the cladistic fear of monotypy.



There is no valid reason to keep a nomenclatural system that is wrong for the sake of not changing the current system. If it is shown to be wrong the names must change. However should you fix a paraphyly by lumping or splitting.



The ultra conservatives would argue you should lump. This is not necessarily a good idea. The genera created from this must stand up as a genus under some definition of the genus and not be a means to avoid the monotypic taxon.



The ultra radicals would argue that you should split, but again the genera created must stand up to a defined value as a genus.



Hence I feel that the mistake in all this is the view of many cladists to split as a general rule but only to do so if it does not produce a monotypic taxon. Their error is one of circularity. They are avoiding the production on monotypy for reasons of methodology. Hence their nomenclature is influenced by methodology. As this is not permissable under nomenclature their names are invalid.



Cheers, Scott
Carettochelys.com


-----
Scott Thomson



If you believe you can or you can't you are always right.

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