[Taxacom] Paraphyletic groups as natural units of biological classification

Curtis Clark lists at curtisclark.org
Thu Oct 2 23:43:25 CDT 2014


On 2014-10-02 4:00 PM, Stephen Thorpe wrote:
> I think you may have possibly missed the point. If P= MM minus M is paraphyletic, then, in order to have a Linnean classification which recognises M, you also need to recognise P (or else elevate all the species in P to the same rank as M). This is the problem!

You don't have to elevate any ranks. Although in times past, some 
cladists insisted that the tree be recoverable from the classification, 
this is impossible. As John pointed out, all that is needed is to assign 
taxon names only to monophyletic groups. We can divide the extant 
tetrapods into three classes, Amphibia, Mammalia, and Reptilia, even 
though the latter two are closer relatives. (Not saying that we should, 
but we could.)

-- 
Curtis Clark        http://www.csupomona.edu/~jcclark
Biological Sciences                   +1 909 869 4140
Cal Poly Pomona, Pomona CA 91768




More information about the Taxacom mailing list