Re: Pollen From Permian/Triassic Extinction Show UV Induced Mutations

[John Bois <jbois@umd5.umd.edu>]

On Sun, 19 Oct 2003, Jaime Headden wrote:

> John Bois (jbois@umd5.umd.edu) wrote:
> (Predation/competition extinction models) would
> seem to make sense in regards to an extinction event on a
> population, rather than a global mass extinction of a percentage
> (however small) of a given range of species. Climate changes, or
> disease, or other natural disasters or alterations can effect a wider
> range of species...

I don't think this is an accepted assumption.  Certainly it would be true
if species were isolated from each other.  Is this the case?  If not, the
evolution of new traits should be expected to have profound effects on
species composition.