Re: The Drunken Sailor's Stumble (was Re: March of "progress")

["Tim Williams" <twilliams_alpha@hotmail.com>]

Ken Kinman wrote:

>     I'm not going to argue with you about Gould's ideas.  He's a bright
> scientist, but some of his ideas are too simplistic in my view (Simon
> Conway-Morris rightly criticizes some of these; see Crucible of Creation).

For once Ken, we're in agreement.  :-)  I find Gould's idea of drift being 
the major theme of evolution a little troubling.  In fact, Gould's own 
discussion on the evolution horses in the book (which correctly rebuts the 
view that equid evolution was *not* governed by forward progress) tends to 
undermine his assertion that diversity is not due to adaptive advantage.  
"Full House" is an interesting read, but I highly recommend "Crucible of 
Creation".

> The most troublesome is that the so-called Cambrian "explosion" was
> supposedly a phyletic explosion of body-plans, when it is more 
> realistically
> regarded as an explosion of hard parts scattered here and there on an
> already well-diversified Metazoan tree.

I respectfully disagree: I think the Cambrian explosion was real, not an 
artifact of preservation.  But Gould (in "Wonderful Life") tends to 
overstate the diversity of Cambrian forms; some "unique" forms are now 
believed to be members of hitherto known forms (e.g. _Hallucogenia_ is 
likely to be a spine-backed onychophoran, not a "phylum" unto itself.)  
Also, Gould's notion that certain Cambrian lineages survived while others 
didn't was due to chance (Dumb Luck) is a little difficult to swallow, in my 
very humble opinion.


Tim

------------------------------------------------------------

Timothy J. Williams

USDA/ARS Researcher
Agronomy Hall
Iowa State University
Ames IA 50014

Phone: 515 294 9233
Fax:   515 294 3163

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