> As far as a statistical > watershed with respect to gene exchange, do
you mean some threshold level at > which gene flow is essentially nill -
thus defining a population?

> > Dan Stephens (509) 662-7443 > Dept. of
Biology fax: (509) 664-2538 > Wenatchee Valley College e-mail:
dstephen at ctc.edu > 1300 Fifth Street > Wenatchee, WA 98801
>
>
Yes. It's analogous to the distinction between a sociocentric kinship
group such as a clan or lineage and an egocentric group such as a
kindred. In the latter case, the boundaries of the kindred can be
defined only with respect to the individual whose kindred it is (i.e.,
all those who that person recognizes as kin). The kindreds of each
individual will be different but may overlap broadly... for example, your
kindred and that of your maternal uncle. It seems that breeding
populations are sometimes discrete... isolated by geographical barriers,
for example... but more often are a series of overlapping circles
focussed on individuals, with the likelihood of interbreeding declining
more or less continuously with distance. In such a case there may be no
"gap" or "clumping" that would allow an observer to define populations
over broad area.

Gene Hunn.