>Really, I think it's pretty well established that "such reproductive
isolation" is impossible to achieve. And what good would it do, anyway?

 Pete, I feel that you're taking the term "reproductive isolation' to the
extreme (a straw man argument).  It is only through reproductive isolation
that various races of Apis mellifera ever evolved. Yet there has always
been some degree of gene flow between contiguous races.  So when I say
"reproductive isolation" I mean to the extent that strong selective
pressure can be put onto the gene pool OF THE BREEDING POPULATION.  Such
isolation need not be absolute.

 >Reproductive isolation leads to reduction in diversity, which is not the
direction the honey bee species has been going for millions of years.
I don't know if you can actually support that statement.  The amount of
genetic diversity over the entire race of Apis mellifera is far greater
than that of any single race.  This fact suggests that reproductively
isolated populations of a species leads to greater diversity within the
species overall.

 >Geographic isolation produces locally adapted bees over time, but the
more locally adapted they are, the more vulnerable they are to climate
change and pathogen invasion, so we are between a rock and a hard place
there.

Cannot agree.  The process of evolution and dispersal are continuous.  Just
look at what happened as the ice sheet retreated from Europe and allowed
previously African-only races to disperse to new territories.  Rather than
being "vulnerable" to climate change, Apis mellifera took advantage of it.

 >I think Brother Adam pretty well showed that a better bee was a
combination of diverse strains; I think the hybrid breeding programs in the
1950s showed the same thing.

 Again, cannot agree. Didn't he actually show that most hybrids were
undesirable?  And that only a few hybrids were "improvements"?  And in
nature, once a hybrid genome is "fixed," it is no longer a hybrid.  Take
the Africanized bee for example.  Over time, it "purified" the original
hybrid, decreasing its overall genetic diversity.

>Everything about HB biology conspires to avoid inbreeding

 I'm completely in agreement with the above statement : )

 >so I don't think reproductive isolation is anything we want. What is
wanted is a way to increase vigor by combining traits rather than isolating
them.

I'm in complete disagreement with the above statement.  Take, for instance,
my own breeding program.  I started with a hybrid mongrel population, of
which 95% of the colonies would, if not treated, collapse from the
varroa/virus complex within a year.  This is despite my having brought a
wide selection of genes into my founding population over the
years--allowing for the combining of traits.  That strategy turned out to
be a dead end.

 Now what I want to do is to intentionally bottleneck that genetic pool to
ELIMINATE those traits that allow for successful varroa reproduction.  If I
can do so without eliminating desirable traits (so far there is no evidence
of that occurring), I hope to end up with a somewhat bottlenecked
population that is free of the nonadaptive traits that promote varroa.

-- 
Randy Oliver
Grass Valley, CA
www.ScientificBeekeeping.com

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