[Taxacom] Metapopulation lineage species concept

[Dr. David Campbell]

> > two groups of connected populations are evolving separately is
sufficient for them to be considered separate species, 
 
>  If they are connected how can they be evolving separately?

If there is even a relatively small level of reproductive preference 
for breeding within the groups rather than between them, it is possible 
for genetic differences to accumulate.  That's the objective part of 
the answer.  I vaguely recall a study a few years back (probably a 
mention in Science or Nature) on a bird with forest and open habitat 
populations that was showing some genetic difference along with a 
relatively low level of preference for breeding within the group, which 
I think made some effort at quantifying the level of interbreeding 
allowable.  

The subjective question, as always, is how much of a difference or 
separation is enough to qualify.  

-- 
Dr. David Campbell
425 Scientific Collections Building
Department of Biological Sciences
Biodiversity and Systematics
University of Alabama, Box 870345
Tuscaloosa AL 35487-0345  USA