Charles,

My opinion is that the two situations are not at all comparable given the
very different geological histories of the NW coast and the
Caribbean/Gulf coast. The time depth of separation is a function of such
factors and should determine the genetic distance as a function of time
in isolation, other thing being equal. I don't believe there has been a
very long period of isolation on the Northwest coast... measuring in the
tens of thousands of years at most.

Gene Hunn

On Fri, 4 Mar 1994 Charles Easterberg <easterbg at u.washington.edu> wrote:
>
> Anybody: is there the same controversy about fish crows hybridizing with
> common crows where they cohabitate, and if not, are there any good
> guesses as to why not and why the NW crow should be such a
> different taxonomic problem? Thanks.