[Tcs-lc] concepts of Higher taxa

[Richard Pyle]

Martin wrote:

> To my understanding at the moment it is not necessary to identify
> the specific concept of the genus one is using when publishing a
> new species. Therefore when there exist mulitple concepts of a
> genus it is not possible to determine which genus concept is being
> expanded by the publication of the new species.

And Paul responded:

> The first sentence here is what prompted my question (perhaps off
> list) last week which was how do nomenclators decide which parent
> (genus) a species belongs to when generic homonym are involved;
> the protologue of the species may contain this information but I
> suspect that it has not always been captured.

I agree that in many/most cases, when a new species is described, the genus
to which it is assigned by the new-species author is not anchored to a
specific concept of that genus name.  However, can we not safely assume that
the new-species author had in mind her/her own concept of the genus when
describing the new species.  Whether or not it is possible to map that genus
concept to previous concepts of the genus depends on how much information
the new-species author provides along with the new species description.  But
the point is, a genus "concept" existed, into which the new spcies was
included, regardless of how poorly that genus concept circumscription was
explicitly defined.  In most new species descriptions, a reference to a
family is also indicated, so the same applies at that rank as well.

As for homonyms, rarely is the case (in fishes, at least), where it is not
clear from the original description which of several hononym genera a new
species was placed.  Is this a common problem in botany?

> This could be a case for requesting a change in the codes such
> that the specific concept being used must be identified when
> publishing a new name.

I don't think that would be a good course of action for the codes, for a
couple of reasons -- mostly because the codes deal with nomenclature, not
concept circumscriptions.

> However, as it stands at the moment, the publication of a species
> within a genus is a purely nomenclatural exercise required to
> satisfy the demands of the binomial naming system and has no
> influence whatsoever on any existing concepts of the genus.

Certainly the publication of a new species has no impact on any
previously-defined concepts, because once a concept is defined, it cannot be
changed by future events.  What does matter, however, is what the implied
genus-rank concept that the new-species author intended to include the new
species within.  If it is identical to a previous genus concept, then no
need to create a new genus concept -- simply map to the existing one.  If it
is expressly different from previous concepts, then a new genus concept is
implicated.  If the answer is not known, then from a TCS perspective, the
new species is placed (by default) within the Nominal-type TaxonConcept
instance for the genus name.

At the very least, we can be confident that the circumscriptional scope of
the implied genus concept of the new-species author included at least the
type specimen of the new species, and the type specimen of the type species
of the genus.

> In order for a new species to be incorporated into a generic
> concept a specific act of inclusion must be performed at which
> point a new generic concept is created.

Wouldn't you regard the placement of a new species within a genus as a
specific act of inclusion?

Aloha,
Rich