[Taxacom] Paraphyletic species and paraphyletic higher taxa

[Kenneth Kinman]

Hi John,
       Think about it harder.  A singly paraphyletic group is exactly
what Chris Thompson said it is, Clade A minus Clade B (which is
basically what I independently said in my own post which appeared just 7
seconds later; kind of spooky that we posted the same point just seconds
apart).  For example, great apes (sensu lato) form a clade A (containing
great apes sensu stricto plus the hominids). If you then subtract Clade
B (hominids), you are left with the paraphyletic group of great apes
sensu stricto (which has been long been called Pongidae by
traditionalists).  This paraphyletic taxon was not the whim of one
authority, but a definition or convention that was very widely
understood and widely used.  Trying to eliminate this useful
paraphyletic Pongidae has done nothing but cause confusion, and you in
particular should be aware of this given your strong conviction that
orangutans (not chimps) are sister group to the hominids.  And there is
still the third possibility that gorillas and chimps clade together not
chimps and hominids.  And that third possibility would explain
similarities between early hominids on the one hand and the chimps and
orangutans on the other.                     
      And as you know from my classification of great apes, my
traditional Family Pongidae (great apes sensu stricto) has remained
relatively constant in its delimitation (Clade A minus Clade B),
although I have on occasion changed the coding of some of the extinct
genera therein and slightly adjusted which side of the line I placed a
couple of fossil genera.  I think it is more important to concentrate on
what are the most appropriate synapomorphies which distinguish "Clade B"
(Family Hominidae in this example) from the great apes sensu stricto
(Clade A minus Clade B), which lack those synapomorphies.  One carefully
chosen synapomorphy may suffice, or better yet two different
morphologies (one related to the brain and the other to bipedality)
which evolved together.   
           ----------Ken Kinman        
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John Grehan responded to Chris:
I would not have thought it was clade A minus Clade B since a
paraphyletic group itself is not a clade, rather what is left of a clade
when one or more subordinate groups are removed (for some
non-phylogenetic reason). 

Chris Thompson wrote:
Not exactly as a paraphyletic group is merely clade A minus clade B. A
polyphletic group is merely clade A minus clades B, C, etc. So, it is
not argument by authority. 
So, second, the compromise for maintaining old paraphyletic /
polyphyletic group in a modern classification is to ANNOTATE the
classification, using the Wiley conventions, etc. That is, for example,
a paraphyletic group can 
be recognized and marked at such (paraphyletic) and then the following
clades can be ordered sequentially, given that the cladogram is
pectinate,  etc. 
Oh, well ... 
Chris Thompson