[Taxacom] More precise sound bite

Curtis Clark jcclark-lists at earthlink.net
Sat Mar 28 09:54:37 CDT 2009


On 2009-03-28 00:45, Mike Dallwitz wrote:
> Does this mean that belonging to a paraphyletic group such as reptiles 
> usually has less predictive value than belonging to any of the monophyletic 
> groups to which reptiles belong?

Knowing that an organism belongs to a paraphyletic group tells you its 
plesiomorphies. Knowing that it belongs to a monophyletic group tells 
you its apomorphies. Knowing that it belongs to a group in a 
classification that includes both paraphyletic and monophyletic groups, 
but not knowing which are paraphyletic and which are monophyletic, tells 
you nothing.

P.S. Yes, Ken, I remember your markers, but afaict you are the only 
person who uses them.

P.P.S. An interesting thought experiment: Could we have a classification 
  formed of only paraphyletic groups? At first that seems absurd, but 
remember that the apomorphies of a clade are also plesiomorphies with 
respect to hypothetical derivative clades not yet evolved. In a sense, a 
lot of the grade-organized early evolutionary classifications were this, 
without the terminological trappings.

-- 
Curtis Clark                  http://www.csupomona.edu/~jcclark/
Director, I&IT Web Development                   +1 909 979 6371
University Web Coordinator, Cal Poly Pomona




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