new, probably brief subject

[Doug Yanega]

Les wrote:

>We all have to deal with hierarchical population structures, in which the
>point at which we designate species versus semispecies, subspecies, or
>races is somewhat arbitrary.  I just wondered, however, how the group
>feels about allopatric (though often adjacent) sister taxa that exhibit
>clear character separation (slightly different male breeding colors, in
>the case of the fishes I work on), but no really remarkable differences.
>Due to their incarceration in peripheral or disjunct habitat patches,
>however, they are probably experiencing independent evolution.  I suspect
>that this is an anthropological issue more than an evolutionary one, but
>it has a big impact on conservation priorities, estimates of regional
>alpha diversity, and so forth.

At least for those entomologists who do not work on butterflies, this seems
to be the criterion by which the decision to designate a subspecies is made
- assuming the person does not mind designating subspecies. There are
taxonomists who will refuse to recognize such differences as meaningful,
and others who will argue that if they are different in any way, then they
should be called species. Which of the three alternatives is chosen in any
given case seems to depend entirely upon the personal philosophy of the
taxonomist. I don't think there is any rule or consensus, nor likely to be,
though one can only suspect that when molecular analyses are done, we'll
find that virtually every "subspecies" is genetically distinguishable and
thus (at least to an adherent of the Phylogenetic Species Concept) a valid
species. If one views the error of failing to recognize a *valid* species
as more devastating than recognizing one that is NOT valid (as would
certainly be the case as far as conservation ethics goes), then a case such
as this should always be classified as a species-level break, and leave it
to someone else to convincingly *disprove* that hypothesis.

My two cents,


Doug Yanega        Dept. of Entomology         Entomology Research Museum
Univ. of California - Riverside, Riverside, CA 92521
phone: (909) 787-4315 (standard disclaimer: opinions are mine, not UCR's)
                http://insects.ucr.edu/staff/yanega.html
  "There are some enterprises in which a careful disorderliness
        is the true method" - Herman Melville, Moby Dick, Chap. 82