>
> >It's because when the trait is distributed in the real world, it swiftly
> evaporates. It is not a dominant trait, like aggression in African bees,
> which tends to move into the population and take hold.


In the "real world" the trait would only evaporate under the absence of
selective pressure by brood pathogens (I'd like to see results for the
Hawaiian feral population, which naturally evolved resistance to AFB after
it decimated the population).

In California operations, which supply much of the bee stock for the rest
of the country, the trait is continually selected for by those
participating in the program.  I was under the impression that a similar
situation would exist in Australia.   Aussie beekeepers tend purchase
selected stock, due to their desire to avoid F1's and F2's hybridized with
the dark feral stock.  Thus my query.  Perhaps Peter, Trevor, or another
Aussie can better explain.

Re traits for "aggression" (actually defensiveness) taking hold, Brother
Adam pointed out that some African races of A. mellifera are quite docile.
Similarly, most European races (apparently originating also in Africa) are
docile.  For some reason, the traits for defensiveness appeared to be
nonadaptive in these races, and not only did not "take hold," but were
apparently bred out by natural selection (suggesting that there is a
fitness cost to maintaining such defensiveness).

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

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