concept 4

[Michael Gochfeld]

warrena at bcc.orst.edu wrote:

> Quoting Ron Gatrelle <gatrelle at tils-ttr.org>:
>
> Thanks Ron!  All I can say is that I would not
> know "biological truth," "functional truth," "absolute
> truth," or the "actual pattern of evolution" if it came
> up to me and hit me in the face :)
>
> I have yet to see an objective definition of a
> subspecies anywhere in print.  Please direct me to the
> source if anyone knows of such a definition.
>
> Andy

Many many years ago, Dean Amadon of the AMNH published the 75% rule for
avian subspecies, indicating that
if measurements (beak or wing or tail or leg or toe) of two populations
showed 75% non-overlap, it was fair to designate the two as subspecies
(assuming of course that they did or could interbreed where the
populations came into contact.  Part of this theme is that much of the
variation in bird species (particularly in the eastern United States was
clinal (continuous) and that there were although New England and Florida
birds might differ in size (or in pigmentation) there was no breakpoint
(or stepped cline) that would allow designation of subspecies.

This may not apply to butterflies, but it is an "objective definition of
a subspecies" in print (AMNH Bulletin circa 1950s).

Mike Gochfeld


 
 ------------------------------------------------------------ 

   For subscription and related information about LEPS-L visit:

   http://www.peabody.yale.edu/other/lepsl