[Taxacom] serious questions about taxonomy and ontogeny

Kenneth Kinman kennethkinman at webtv.net
Tue Sep 14 22:14:53 CDT 2010


Hi Stephen,
        The ultimate question of our time is still what are the best
"ways of cutting up the cake" that we call the Tree of Life.  Working
out the phylogenetic relationships is clearly important and molecular
sequencing has often helped us do that, but those (strict cladists) who
insist that the tree of life must always be formally cut up in strictly
phylogenetic fashion regretfully ignore the paraphyletic reality of
evolution.          
      Granted that one can safely often ignore the complications of such
paraphyly (when extinction has eliminated the intermediates and they
left no fossil record), thus making a purely phylogenetic (strictly
cladistic) classification an excellent and justifiable simplification in
many cases.  However, to do so for ALL taxa when the intermediates are
known (and paraphyly is clearly informative) is just Hennigian zealotry
that simplistically (dare I say ignorantly) pretends that paraphyletic
taxa are unnatural, uninformative, or any other negative term they want
to throw at formal paraphyletic taxa.      
       Such Hennigian-inspired definitions are NOT science, just
conventions that are often useful (as pointed out above), but such
conventions are also deterimental in many cases, and thus PhyloCode (the
formalization of such folly across the board) will not only ignore and
stigmatize perfectly good paraphyletic taxa, but will also propose a lot
of formal names for taxa that aren't really holophyletic (clades)
anyway.  Those who propose such names are really more like lawyers than
scientists.  They've swung the taxonomic pendulum too far and are
therefore often as bad as the extreme old-fashioned  paraphyleticists
that Hennig was reacting against.     
        Neither extreme is helpful in the long run, and eventually the
big funders will come to the realization (but it seems to be taking a
painfully long time for that to happen) that strict cladism
(holophyletic taxa only) is often more legalistic (and artificial) than
scientific.  Beware of phylocodists who use terms like unnatural,
unscientific, or uninformative in reference to every paraphyletic taxon
they see.  They are the ones most likely to have proposed clade names
for groupings that are not holophyletic.  I've seen it happen repeatedly
over the last 20 years, and PhyloCode would only make it happen even
more often.  PhyloCode is not science, but just an extreme manifestation
of legalistic definitions (perhaps sometimes helpful, but often very
harmful).         
            -----------Ken Kinman  
===================================
Stephen wrote:
So what if taxonomy isn't science? Neither is collection
curation/management nor scientific illustration, but these things are
all still worth doing as support for systematics. Actually, I think that
there is no objective test for species boundaries, so we might just all
have to face the truth that species (and higher taxa) are all just ways
of cutting up the cake. Systematics is left to work out the phylogenetic
relationships between these bits of cake ... the only bit of science
left ... 
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