Real species and ideology

[Richard Pyle]

> It is often a non-trivial task to distinguish between two
> subspecies separated by a morphocline, on the one hand, and two species
> separated by an area of introgressive hybridization, on the other, but
> genetic tools can often be brought to bear to sort out these issues.

How would you distinguish the two separate patterns (morphocline of
subspecies vs. introgressive hybridization) -- even with the best of genetic
tools?  Indeed, is there anything fundamentally different between the two
patterns, other than our artificial imposition of the rank "species" in one
case, and "subspecies" in another?

This gets right to the heart of my original question to you, about defining
the terms "real" and "artificial" in an evolution/species context, and in
supporting one perspective over the other.  This thread has taken a
different direction than what I had hoped it would, but the above quote from
Curtis brings it back to what I'm most interested in understanding.

Aloha,
Rich

=======================================================
Richard L. Pyle, PhD
Ichthyology, Bishop Museum
1525 Bernice St., Honolulu, HI 96817
Ph: (808)848-4115, Fax: (808)847-8252
email: deepreef at bishopmuseum.org
http://www.bishopmuseum.org/bishop/HBS/pylerichard.html