The ICZN rules deal with Nomenclature not systematics. Therefore wether there is a requirement under the ICZN to deal with paraphyly or not is irrelevant.

What is relevant is the paradigm in which the researchers find themselves. If they are under a cladistic paradigm then the science of that will require a taxonomic solution to a paraphyletic taxon.

I am neither a splitter or a lumper but will do what I consider necessary under the paradigm I am working from. I happen to agree that morphologically homologous taxa are sometimes separated. I have also found that when these taxa are re-examined and looked at more closely, particularly internally, they are not the same.

I am not personally in favour of the use of DNA sequence data in systematics, as I am a taxonomist/ palaeontologist I see it to be useless as the majority of the testible taxa return a non-result. Hence I think DNA has its place in population studies and other below species work.

Cheers, Scott
Carettochelys.com