Richard you make several good points, and I should state that I see species as more "real" than
other ranks.

Perhaps this example might help show the distinction I am trying to make.

When a medical entomologist states that a species X, breeds in shallow ephemeral pools and
has a preference for human blood meals do they mean

The taxonomic hypothesis A. o. has these properties or

the "natural" unit currently called A. o. has these properties ?

I think they mean the second and would benefit if the statements made about that natural unit
could stay linked to the natural unit species concept over time. 

Unfortunately under the "species is the taxonomic hypothesis" system they don't.

Does this help clarify the distinction I am trying to make?

Thanks!

- Pete




On Sat, Jan 24, 2009 at 6:55 PM, Richard Pyle <deepreef@bishopmuseum.org> wrote:
> 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



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Pete DeVries
Department of Entomology
University of Wisconsin - Madison
445 Russell Laboratories
1630 Linden Drive
Madison, WI 53706
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