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the cladists

Joe Felsenstein joe at evolution.genetics.washington.edu
Sat Oct 7 23:22:11 EST 1995


In article <Pine.SOL.3.91.951007153514.13198A-100000 at paladin.wright.edu>,
SCOTT ROUSH  <s005sar at paladin.wright.edu> wrote:
>I have recently read that cladistics has been proclaimed to be "based on 
>punctuated equilibria."

Let me spring to their defense.  Phylogenetic systematics ("cladism") is not
dependent on acceptance or rejection of a punctuated equilibrium view.
However some of its adherents have been attracted to a punctuationist
view, perhaps in part because of belief in the irrelevance of population
genetics.  But there is no sense in which cladism is "based on" PE.

>I have also read "cladists... can only smirk at 
>the suggestion that cladistics derives from puctuated equilibria. 

(Perhaps because there are some cladists who can only smirk about anything).

>Cladistics...has been ridiculed in ultra-Darwinian quarters because of 
>the apparently antievolutionary stance adopted over the last decade by 
>some of its more ardent supporters."  

This is an exaggeration, at a minimum.  There are cladists (particularly
the "pattern cladistics" school which was noticeable in the early 1980's
but is silent now) who adopted not an antievolutionary stance but an
operationalist stance.  This is much like the stance of pheneticists like
Sokal and Sneath.  Both groups said, in effect, "we of course think that
evolution happened, but our methods discern a pattern, and it does not
matter operationally whether that pattern is or is not the phylogeny,
it's just the repeatable pattern that one gets, and we should use it as
such."

That is quite a bit different from saying evolution didn't happen;
opponents of pattern cladism mischaracterized it as such.

-----
Joe Felsenstein         joe at genetics.washington.edu     (IP No. 128.95.12.41)
 Dept. of Genetics, Univ. of Washington, Box 357360, Seattle, WA 98195-7360 USA



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