Re: the evolution of disparity in body plans (was Re: synapomorphies)

[gbarden@mailhost.dpie.gov.au (Graeme Barden)]

At 02:10 PM 13/02/96 -0500, Mickey Rowe wrote:

> In short, Gould's major thesis in [_Wonderful Life_, that most of
> the odd organisms preserved in the Burgess Shale were far removed
> from the lineages that have survived to the present -- MR] was most
> likely wrong.

Is the situation described in "Wonderful Life" so unlike situations we find
today (albeit in incredibly shorter timefrmes)?  Consider a newly disrubted
habitat, with complete collapse of its ecology.  In general you will find a
conglomeration of forms moving into the site, with a gradual 'weeding out'
until a stable ecology of fewer species is formed.  Now this may be
competitive exclusion, rather than selection, but I do think the comparison
reasonable.

Graeme.

[Since this was a response to me, I'll cut to the chase and respond
here.  (Let me know if you think I shouldn't do such things.)  In
principle Gould's proposal is reasonable, but as a scientific
hypothesis it is open to test.  The consensus amongst those who
actually study the organisms appears to be that the idea has failed to
survive critical scrutiny.  I won't comment any more on this since
it's Chris Nedin's bailiwick. Not that he can be trusted or
anything... -- MR]