Continuity, reticulation, and classification

Thomas DiBenedetto tdibenedetto at OCEANCONSERVANCY.ORG
Thu Jul 26 09:41:03 CDT 2001


-----Original Message-----
From: Ken Kinman [mailto:kinman at HOTMAIL.COM]
Ernst Mayr...doesn't even consider them real classifications, ...
     Mayr and Ashlock (1991) state:  "Cladists are far more subjective than
traditional taxonomists are.  They have adopted a series of arbitrary
conventions that are in complete conflict with the otherwise universally
adopted classifying principles enumerated in Chapter 6.
---
Mayr doesnt consider cladistic classifications to be real classifications
because they do not try to incorporate all the subjective conclusions about
how taxa stand in relation to one's model of evolution, as Mayr thinks that
real classifications should. So what? This is to be expected. Cladists have
a different conception of what a classification should be.
As far as cladists being "far more subjective", I think Mayr is simply
wrong. The "arbitrary conventions" are in fact, a respect for empirical
findings. And the "universally adopted classifying principles" are in fact,
nothing more than his own.
----------
And Mayr (in his 1998 book) states:  "There is nothing in any theory of
classification that would require one to rely on the principle of holophyly.
---
There certainly is in the cladistic theory of classification. Unfortunatly,
Mayr seems to think that his theories are "universal", and the "only real
theories", such that any other theory simply doesnt count.
---------
  Indeed, the artificiality and heterogeneity of holophyletic taxa have been
the source of most adverse criticism of cladistics."
---
This is plainly false. Cladistic monophyletic taxa have been criticized for
many reasons, but artificiality is not one. Even you seem to recognize that
these taxa deserve recognition. For what possibile reason would you
recognize them other than the obvious fact that they represent (our best
reconstruction of) real lineage branches?
------------
The bottom line is that strictly cladistic classifications are
generally criticized by everyone except the strict cladists themselves
---
Not at all. If you read the literature of phylogeography, genetic
evolutionary modeling, the evolution of ontogeny, or any other emerging
field in which multiple taxa are analyzed in such a way that their
relationships are a factor, you will see a universal use of phylogenies
(cladistic classification). If you wish to study evolution, you need to know
that birds are dinosaurs, you need to know the history of lineages - a
classification which obscures this is worse than useless. How many times
have you ever seen an eclectic classification _used_ as the scientific tool
that a classification should be?


Tom DiBenedetto




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