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Informed Discussion of Beekeeping Issues and Bee Biology

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From:
randy oliver <[log in to unmask]>
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Informed Discussion of Beekeeping Issues and Bee Biology <[log in to unmask]>
Date:
Tue, 2 Sep 2014 08:14:18 -0700
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 >complex behaviors that can be adapted through epigenetic changes over
time to local environmental triggers.  And you won't necessarily find any
changes in the genes themselves. ..  It shows us how wonderfully equipped
the bees are to adjust to changes in their environment without necessarily
having to wait for a mutation to come along.

Again, Christina, Dick, and I are in complete agreement.  The beautiful
thing about genetic and epigenetic *regulation* is that a species (or
individual) need not change a whole slew of genes to adapt to an
environmental cue--rather the upregulation of a critical regulatory gene
can change all sorts of traits simultaneously.

An example: the default for any fertilized bee egg is to become a drone.
It is only if that egg possesses a different allele of the sex determinant
gene on each of its two chromosomes that it will become a female.  But the
sex determinant gene does not code for any feminine property--it simply
upregulates the expression of the Feminize gene, which in turn upregulates
an entire suite of genes responsible for the differences between a male or
female bee.

But the story does not stop there.  That feminized egg then can (still
without any genetic change whatsoever) develop either into a queen (the
default) or a worker.  The many physiological,, morphological,  and
behavioral differences between a queen and a worker are entirely due to
epigenetic differences in expression of the genes of that individual (now
female) larva.

My point is that from a discreet single set of genes, a single egg could
develop in any of three different directions--into a drone, queen, or
worker.  No genetic change was necessary for that developing worker to
adapt by expressing a different phenotype from essentially the same
genotype.  And I'm not even discussing the possibility of further
differentiation of an individual worker into either a diuntinus bee or a
"normal" worker (which then physiologically and behaviorally changes over
its life from cleaner to nurse to mid age behavior to forager physiology
and behavior).

I hope that the above example helps to explain the enormous adaptive
capacity of the honey bee.  If a single bee has such plasticity, imagine
the plasticity of a population of bees!

  >However it also shows us that bees and their genomes are not so
conveniently manipulated as some would like us to believe.  Also a good
thing, IMO, because we humans are like bulls in a china shop where genetics
and environmental management are concerned....acting first, then "oops"
later.

We are currently experiencing the "oops."

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

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