Guy Hoelzer  wrote in
news:c2rk8h$1642$1{at}darwin.ediacara.org: 

> in article c2r15h$ve9$1{at}darwin.ediacara.org, Jeffrey Turner at
> jturner{at}localnet.com wrote on 3/11/04 4:44 PM:
> 
>> Guy Hoelzer wrote:
>>> in article c2mel7$2hk9$1{at}darwin.ediacara.org, Jeffrey Turner at
>>> jturner{at}localnet.com wrote on 3/9/04 11:04 PM:
> 
>> Genetic drift may explain why
>> there are similar but not identical species of finch (or somesuch) in
>> England and Ireland but it hardly seems hold any answers for the more
>> complicated examples of evolution.
> 
> I would side with Gould and Lewontin (Spandrels of San Marco) on the
> notion that drift is the default explanation for all of these
> phenomena unless shown to be insufficient.  A gut feeling that it is
> insufficient may prove to be right, but it is not a basis for critical
> judgment. 

Dennett has already effectively undercut the comparison of exaptations to 
"spandrels", since the so-called spandrels (apparently the correct term 
for what G & L discuss is pendentives) are in fact an architectural 
choice, not an architectural necessity. In any case I thought the point 
of that paper was that some features are byproducts of selection, not 
positive products of drift. 

Given my previous attempt on this thread to differentiate phenomena 
primarily attributable to selection from phenomena primarily attributable 
to drift (all are in fact products of both), I would request that you 
clarify what you mean by "all of these phenomena". The English and Irish 
finches may meet the requirements of a default assumption for drift, but 
they may not, and drift only qualitifies as a default assumption for a 
limited set of observed phenotypic differences. 

Yours

Bill Morse
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