[Taxacom] Semi-holophyly is definitely better (was: paraphyly discussions)

Kenneth Kinman kennethkinman at webtv.net
Fri Dec 24 09:31:32 CST 2010

Hi Richard,
        Thanks for the clarification.  I think we are broadly in
agreement, although there seems to be a semantic disagreement over the
word paraphyletic.  I guess it doesn't matter too much, since I don't
like strictly paraphyletic taxa either.  That's why I render them
semi-holophyletic by including an exgroup marker (and thus holophyletic
in an informational sense).        
       So my New Year's resolution is to refer to such taxa (theories
"of diachronic relationships") as semi-holophyletic (i.e.
semi-paraphyletic, which means the same thing).  The word paraphyly does
carry a lot of baggage, and strict paraphyly isn't informational enough
if one omits the exgroup information.  Therefore, since
semi-paraphyletic might also be burdened by some of that historical
baggage, I will use the term semi-holophyletic as much as possible.         
            -----------Ken Kinman                           
Richard Zander wrote:
     Paraphyletic groups are unnatural because they are structuralist
constructions involving nonempirical hidden causes and unobservable or
unnamed entities. They are relationships in the present. They are
evidence that COULD be used to form theories, but unnamed "shared
ancestors," if preserved as part of the solution, block that. 
     If "some workers do go beyond mere phylogenetic analysis (and don't
skip the theory part)" as you say, that's fine, and then the
paraphyletic group becomes a theory of diachronic relationship, and is
scientific, since you can name the node. 

More information about the Taxacom mailing list