Clades, cladons, and "cladifications"

Ken Kinman kinman2 at YAHOO.COM
Tue Jun 15 09:01:17 CDT 2004

Nico wrote:
    Consider a larger cladogram with a sequence of 5 basal bifurcations. Their respective supports are number of 1, 1, 10, 1, and 1 synapomorphies. There is nothing in cladistics that would force me to make the "cut" for a rank (say, a subtribe of insects) at the least supported rank. If I want my cladistic subtribe to communicate a lot of evolutionary differences, I'm free to let it have 10 synapomorphies, not just 1.
      I completely agree that this is a perfectly acceptable approach.  However, if the 10-synapomorphy branch leads to birds (and the shorter branchs to traditional dinosaur taxa), I think it is equally acceptable (and natural) to classify the birds at a higher rank.  Strict cladism FORBIDS one from doing this because it makes dinosaurs paraphyletic.

      In my view, Hennig was wrong to insist that paraphyly should be ENTIRELY eliminated.  What he SHOULD have insisted is that paraphyly be clearly marked in the classification, with {{markers}} of some sort show the cladistic position of the removed exgroup.  Having such a paraphyly option could have saved us 35 years of needless bickering and a schism that has ultimately resulted in a notorious PhyloCode.  Just give me the paraphyly option and I promise to always explicitly mark such groups.  What we should be eliminating is the old "fuzzy" unmarked paraphyly that fails to convey valuable cladistic (sister group) information.
           ------- Cheers,
                        Ken Kinman

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