How do others think of species?
I do not think that species are any more "real" than subspecies, genera, and families. I believe all of these things are abstract notions representing aggregate sets of individual organisms, defined and labelled by humans in a way that allows us to communicate with each other with some degree of efficiency (though certainly not perfect efficiency).
Having said that, I think it is highly practical in many cases to treat units of "species" as though they were cohesive, singular, "real" entities that exist in nature (within a given slice of geologic time) independantly of human interpretations, because doing so also facilitates communication. This is particularly true in cases characterized by realtively broad periods/populations of phenetic and/or genetic stasis, homogeneity and consistency, punctuated by relatively small periods/populations of phenetic and/or genetic divergence, heterogeneity and spectral forms. I think the dangers and problems (nomenclatural instability, poorly supported hypotheses, confusing and conflicting lines of evidence) are most evident when people attempt to apply assumptions based on the "reality" of species to cases that are not so characterized.
Thus, I do not believe that species are "real", but I believe there are contexts in which is it useful to think of them as such.
I think the practice of identifying individual organisms to species concepts is mostly independent of whether those concepts represent human-defined constructs, or "natural" units that exist in nature independantly of human interpretations. Analagous to my view of species, I think that morphological and genetic characters are properties of organisms, but in many cases it is highly practical to treat them as though they are properties of "species", given the same caveats described above.
Aloha, Rich
Richard L. Pyle, PhD Database Coordinator for Natural Sciences and Associate Zoologist in Ichthyology Department of Natural Sciences, Bishop Museum 1525 Bernice St., Honolulu, HI 96817 Ph: (808)848-4115, Fax: (808)847-8252 email: deepreef@bishopmuseum.org http://hbs.bishopmuseum.org/staff/pylerichard.html