Re: Species [arbitrary to a degree]

[Graydon <graydon@dsl.ca>]

On Fri, Oct 19, 2001 at 04:04:50AM +0000, Ken Kinman scripsit:
>      Asexual reproduction is certainly a problem for species concepts.  
> However, I think it is even more of a mistake to so quickly dismiss the 
> important implications of "ring species" where populations (e.g., 
> subspecies) can interbreed with adjacent populations just fine, until the 
> species circles around (circumpolar, around a mountain range or whatever), 
> and the populations at the end of the ring can no longer interbreed at all.
>     I've always regarded the ring species as a prime example of the 
> "fuzziness" of the boundaries between species "in space".  Throw in the 
> fourth dimension and the fuzziness gets even worse (which makes 
> paleontological species all the more controversial and difficult).

The circumpolar gulls are only a problem because of trying to use
'species' in a way that relates directly to morphology.  If you think of
them as a population of genes, you can recognize that the mobility of
the genes within the population is unimpaired for having directional
constraints.

-- 
                           graydon@dsl.ca
               To maintain the end is to uphold the means.