Species as "Hypotheses"

Richard Pyle deepreef at BISHOPMUSEUM.ORG
Sat Jul 10 20:21:09 CDT 2004


> * the hypothesis is that the species delimited by nomenclatoral
> circumscription and described/diagnostic characteristics of individuals
> corresponds to a species under the species concept explicitly or
> implicitly endorsed by the revisor -

O.K., that I can understand.  As I said towards the end of my post, species
can be thought of as hypotheses given an objective set of criteria to
distinguish whether two organisms belong to the same species, or a different
species.  The problem, of course, is that among the available species
concepts that attempt to establish such objective criteria, none achieve the
goal of being both *truely* objective, AND even remotely practical or useful
(let alone broadly accepted).  So, lacking such a species concept, isn't it
wiser to think of (and represent) species as defined, rather than as
testable hypotheses?

> "the individuals with these
> characterisitcs collectively represent a
> biological/phylogenetic/whatever species." The hypothesis is falsified
> by finding evidence that lumps or splits the delimited taxon under the
> designated species concept.

Again, if a species is discussed within the context of an objective
definition, it is indeed falsifiable.  But as far as I can tell, this is
almost never done in the real world. And when it is, close scrutiny of the
chosen species concept often reveals it to be either: a) not actually
objective after all; or b) essentially impossible to apply to actual living
organisms. Or both.

> The name is an accident (the oldest available within the delimited
> specimens) - the species limits and the conspecificity of the indivduals
> within those limits are the hypothesis.
>
> eh?

Well...I agree that the name is an accident, but I don't agree that, in
practice (or even in any reasonable theory), the species limits and the
conspecificity of the indivduals within those limits constitute a
falsifiable hypothesis.  I still see the notion of a species (or any ranked
taxon) as something that is defined, rather than tested, in almost all
references to taxa in scientific literature today.  I know there have been
extremely well-worded articles and books discussing these sorts of things in
great detail (I've read many of them).  But I don't see that high-minded
discussion (which, as far as I can see, never has, nor likely ever will,
achieve universal or even majority consensus) applied to most scientific
literature that makes reference to taxa.

If, like Fred, everyone who sees species as hypotheses does so only in the
context of a species concept that offers a set of purely objective criteria
for determining species boundaries, then I understand where you're coming
from.  What I don't understand is what that perspective has to do with how
taxonomy is actually practiced by taxonomists.

Aloha,
Rich

Richard L. Pyle, PhD
Natural Sciences Database Coordinator, 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




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