Keith wrote:
>How is lowered defensiveness tied to survival?  

Lowered defensiveness in some strains could have arisen by 

1) Lack of need.  If a trait is not needed, natural selection tends to let
it die out. Obviously, a high degree of defensiveness is costly to the
organism and if there is no payoff for it, it causes that organism to be
less fit since it allocates energy to a behavior that has no payoff. So an
organism that doesn't waste energy on defensiveness could be *better fit*. 

2) Reallocation. If hoarding is more important for survival, a successful
colony might allocate more bees to foraging than to defense. In an area
where the chief obstacle to survival is a six month dearth and very low
temperatures, excellent hoarding and the ability to generate heat from the
calories would give an edge to survive. But they might have fewer guards on
duty as a result a higher percentage of bees being out foraging.

You have to view these factors as all *interconnected*. Like, what makes a
good car? Is it fuel efficiency, handling, safety, etc.? They are all
interconnected and one can't be improved without some sacrifice of another.
So, the colony must balance factors like foraging efficiency, ability to
select a proper nest, defensiveness, ability to return from long distances,
mating attractiveness, swarming, hygienic behavior, the list goes on. 

It simply isn't good enough to be very good in only one thing: the hive has
to be really good in the things that matter for the environment in which
they are trying to survive. Different conditions will require different
coping mechanisms. If there are flowers year round, hoarding is not so
important. If the bees are well protected then defensiveness is not so
important. They may not lose a trait altogether, but they may become much
better at other things. 

People have bred bees that were better at pollinating.  Now we are trying to
get bees that can handle a predator against which they don't have a good
defense. This may or may not even be possible. You can't breed pigs to fly,
for example. As we have said, perhaps the colony selection process is
actually selecting less virulent mites. One has to establish attainable
goals in breeding. 

When you talk about leaving bees alone and letting nature takes its course,
you might remember that WE are a product of evolution, that evolution is
still going on and we are a major force in it. Of course, with that
realization comes responsibility for the the many species that are now under
our care. We have certainly proved our ability to muck things up. 

Warning: some of my ideas are sheer speculation, so if anyone has a problem
with what I am saying, it's just Sci Fi, OK?

pb

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