I think it might be useful to think of the species concept as separate from associated phylogenetic hypotheses.

Human's assert that a given species has a particular phylogeny - it does not define the species concept.

The species concept should be defined by a collection of individuals, specific characters and perhaps a database of DNA sequences that help characterize the variation within the individual's that are instances of the species concept.

The species concept should be documented with open, web accessible descriptions that allow humans and machines to determine what species concept is the best match for a particular specimen.

Since the current scientific name entails a particular phylogenetic hypothesis, a resolvable taxon concept identifier is needed to help clarify what the human specimen identifier actually meant when they identified a particular specimen.

The species concept documents should be "testable".

These species concept documents include the names that have been associated with a particular concept, but the names themselves do not define the species concept. This means that a new phylogenetic hypothesis will usually
not change the species concept identifier.

Without some open resolvable species concept document, various attempts to map name usage will still leave considerable ambiguity as to what particular species concept is most appropriate for a particular specimen.

The current problems are the result of the co-mingling of phylogeny and species definition in the form of the genus and specific epithet, the fact that current species descriptions are often interpreted by different people in different ways, and inaccessibility of many species descriptions.

I think that something along the lines of what I have proposed would solve many of these problems.

Respectfully,

- Pete



On Wed, Jul 7, 2010 at 9:28 AM, Richard Pyle <deepreef@bishopmuseum.org> wrote:

Hi Mark,

I agree with everything you say (which is why I think that essentially
everything related to "taxa" should be represented through Usage Instances).
I also agree that taxonomists do not often articulate the scope of their
taxon concepts by enumerating the included organisms. However, I would argue
that when most (all?) taxonomists conceive of a taxon concept, the "essence"
of the concept is the set of organisms implied to be circumscribed by it.
Thus, there is an historical disconnect between what a taxonomist means by a
taxon concept, and how a taxonomist articulates the scope of that concept.
And therein lies what I think is the biggest biodiversity informatics
challenge.  That is, one of the most fundamental units of biology has a
history of being very imprecisely defined by the practitioners who establish
those units.

Aloha,
Rich

> -----Original Message-----
> From: Mark Wilden [mailto:mark@mwilden.com]
> Sent: Tuesday, July 06, 2010 5:46 AM
> To: Richard Pyle
> Subject: Re: [tdwg-content] Taxon Concept dilemma
>
> On Tue, Jul 6, 2010 at 6:10 AM, Richard Pyle
> <deepreef@bishopmuseum.org> wrote:
>
> > This is why the only way we're going to be able to establish
> > RelationshipAssertions (sensu TCS) is via third-party
> assertions.  In
> > other words, someone is going to have to assert an opinion over
> > whether the implied members of Smith's Aus bus would have
> included the
> > population in Hawaii, and whether the implied set of Jones' Aus cus
> > would have included the population in the Marshall Islands.
>
> I think that a "someone" is always asserting such an opinion
> - Smith and Jones included. There is no Platonic ideal of a particular
> species. Every single classification is a matter of educated opinion.
> Smith has one opinion and Jones has another opinion. Brown may step in
> and decide that Smith's opinion is the correct one - but that's just
> another opinion. Consumers of the classification choose whose opinions
> are the most useful.
>
> A taxon is always related to a taxon-assigner. In this sense,
> "circumscription" is perhaps not the best way to think about it,
> because very few assigners actually determine taxa by enumerating
> organisms.
>
> The idea of researchers creating taxa, and third parties adjudicating
> them to arrive at the "true" classification, is too limited. It's
> third parties all the way down.
>
> ///ark


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