>>According to my copy of "The Compleat Cladist", that grouping would be polyphyletic. >>



That is not surprising because the birds have a different nearest common ancestor than the frogs. Lumping these two groups would create a polyphyletic group.



>>But I think the distinction is can get fuzzy is some circumstances, therefore I prefer to simply distinguish between monophyletic and non-monophyletic>>



Actually, there is no circumstance in which a group that consists of only birds and frogs (and nothing else) could be considered paraphyletic, so it is not necessary to be ambiguous. Cladists use the term "non-monophyletic" to hide the fact that the taxon they are dismantling is paraphyletic instead of polyphyletic. Since most biologists do not discriminate against paraphyletic taxa, cladists could not usually persuade others to go along with their taxonomic proposals without concealing their true intentions of dismantling paraphyletic taxa. Cladists who use the term "non-monophyletic" in their taxonomic proposals are therefore dishonest. If the taxon/taxa they propose to disqualify is paraphyletic, then they should say so, instead of hiding behind an ambiguous term like "non-monophyletic." Hennig invented the term paraphyletic; his followers should use it if it is so important to them that they have no qualms with generating taxonomic chaos in their unending quest to rid this world of paraphyletic taxa.



>>. You can download a copy of "The Compleat Cladist" (that is the correct spelling) if you want more info. Just use the google.>>



If one wants to be a "compleat cladist" then this is a good source of information. If one wants to be a scientist, then there are better sources of information for the aspiring systematist.

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