David Wright wrote (I love writing "Wright wrote" for some reason):

"It is not clear that all named subspecies of North American birds would in
fact make good PSC species. Apparently many subspecies lack diagnostic
characters and would not be recognized as PSC species."

I agree entirely, and if we don't drop the subspecies concept we should at
least get a little more rigorous about applying formal names only to
populations that are well-defined. But, museum maven that I am, I could
show you a *whole* bunch of named subspecies that in fact do have
distinctive characteristics and well-defined geographic range, e.g. in
Hairy and Downy woodpeckers, for just a couple of examples. The
differences are not large, yet they are consistent. Although I can see the
utility of the PSC, and I applauded many of the splits I discovered in
going through Sibley & Monroe's world list, I personally would be quite
uncomfortable with 5 or so "species" of Downy Woodpeckers spread across the
continent and would wonder exactly what we were accomplishing by applying
this concept so extravagantly.

Black-capped Chickadees west of the Cascades would certainly qualify for
species status, as they are quite distinct morphologically, yet no
differences between them and other populations were found in one DNA study.
I wish the peculiar song dialect characterized the whole population rather
than just the southern part of it--that would have furnished great
additional evidence for species status. We could have had the "Oregon
Chickadee" back!

And Joe Morlan wrote:

"Are you saying that the AOU Check-List Committee has adopted the
phylogenetic species concept? This is news to me."

No, I just stated that the committee "is now favoring this new concept in
its decision-making process;" I meant to imply merely that the PSC is
becoming increasingly favored. At least one committee member is a strong
proponent of the concept, and it is merely causing them to look at
"species" with new eyes. They still insist on published data and aren't a
rubber-stamp group even when something has been published. I agree with
you that the splits so far could have been justified under the
biological-species concept, but the combination of the emergence of the PSC
as an exciting concept and the molecular evidence becoming available will
be pushing the committee ever further in that direction.

Dennis Paulson, Director phone: (206) 756-3798
Slater Museum of Natural History fax: (206) 756-3352
University of Puget Sound e-mail: dpaulson at ups.edu
Tacoma, WA 98416