Peter Borst wrote:
>...  I don't see how a benign host/pest relationship would *ever* develop
in a fatal disease.

I don't have enough experience as a beekeeper to agree or disagree with you
about the transmission of mites between beehives, but there are many
examples of fatal diseases developing into more benign relationships with
the host.  Human pathologies are the best studied so the best examples I
know of are the childhood diseases - chickenpox, measles, mumps, etc.  They
are excellent examples of pathogens that the archeological record shows
were far more virulent than they are today.  (Steven J Gould had some very
good essays on this topic.  I think they were in "The Panda's Thumb".)

>... Evolution is an exceedingly slow process and can hardly be depended
upon for our purposes.

Actually, the current understanding of evolution is not that slow at all.
The argument goes that species tend to stay stable for relatively long
periods until something in the environment changes enough to bring the
accumulated random mutations to the fore.  Once a beneficial adaptation
really takes hold, it propogates across the species very quickly.  The
concept is called Punctuated Equilibrium and was very well described in
another Scientific American article several years ago.  (Sorry, I'm not
able to look up the exact issue right now.)

I do believe that new pathogens would qualify as a significant and
comparatively sudden new environmental pressure.

>...  But that is not evolution -- it is selective breeding,

Here, I think you are making a distinction without a difference.  Selective
breeding is evolution.  Humans are part of the environment for bees.  We
can pressure them toward resistance mutations or we can counter-balance
other environmental factors and pressure them away from those same
mutations.

>... which can bring about good as well as negative effects.

Evolution also has both positive and negative effects.  Evolution and
selective breeding are both about trade-offs.  I was reading an article in
the paper just this morning that scientists discovered a single gene in
mice that prevents cancer but apparently causes many of the debilitating
effects of aging.

Okay, I'll get off my soap box now.  But the original article that adony
melathopoulos cited was very good.  I recommend it.

Mike Rossander



______________________________________________________________________
This message contains information that may be privileged or confidential
and is the property of the Cap Gemini Ernst & Young Group.  It is intended
only for the person to whom it is addressed.  If you are not the intended
recipient, you are not authorized to read, print, retain, copy,
disseminate, distribute, or use this message or any part thereof. If you
receive this message in error, please notify the sender immediately and
delete all copies of this message