Eugene Hunn <hunn at u.washington.edu> writes

> 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.

This has been a fun discussion. Thanks to Dan Victor for making it
possible.

1.) I've decided to take NW Crow off my Chelan Co. list. I've made it
to well over 200 species without the crow.

2.) Who said the NW Crow needed to develop in isolation? If there is in
fact a cline that extends along the coast from Alaska to southern Calif.,
then any such isolating mechanism is unncessary. True? I'm asking.

3.) There seems to be some selection pressure for crows exploiting the
beach environment to be small. It would be interesting to have some
genetic markers that could be traced. If only this could be done in
some sort of historical context.

From: Jerry Tangren, Wenatchee WA
<gsw$en at wsuvm1.csc.wsu.edu>