Clades, cladons, and "cladifications"

Ken Kinman kinman2 at YAHOO.COM
Sat Jun 12 11:04:39 CDT 2004

Brian Tindall wrote:
      it is interesting to note that Hennig used the term "phylogenetic systematics", and this has become equivalent to "cladistics".  However, if I recall correctly the term "clade" was coined by Huxley (in about 1959), with no reference to methodology and simply defined a clade as a "monophyletic group".  I some of the literature I read I am seeing the term "monophyletic clade" with increasing frequency!!
Dear All,
      As Ernst Mayr and many others have pointed out, eclectic systematics is ALSO phylogenetic.  It just isn't PURELY phylogenetic!!!  So a better phrase for the monistic approach would probably be "strictly phylogenetic systematics" (or better yet, strict cladism), while eclecticism is dualistic (including distance information as well as phylogenesis).

      I don't recall Huxley's 1959 paper, but back then the term monophyletic generally meant a group with a single common ancestor (either paraphyletic or holophyletic).  Then the restriction of the meaning of monophyletic (by the strict cladists) is why Peter Ashlock eventually proposed the new term "holophyletic" (= strictly monophyletic).  Unfortunately his proposal was harshly criticized and ignored by strict cladists and their students, and the semantic confusion (which that term would have ended) has thus continued to this day.

      Finally, Ernst Mayr proposed the term "cladon" for holophyletic groups in 1995.  I don't think that term will ever catch on, so I don't even use it.  However, I REALLY like his corresponding term "cladification" (= strictly cladistic classification).   It is totally appropriate given that cladifications lack the class concepts of true classifications.
        ------- Cheers,
                     Ken Kinman

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