From: Robert Bradbury (bradbury@genebee.msu.su)
Date: Tue Jan 25 2000 - 20:53:56 MST
On Tue, 25 Jan 2000, Dana Hedberg wrote:
> I wonder if our own genetic "defenses" are the reason behind the
> phenotypic response of infection. DNA provides for the showing of
> infection by nastiness so that the species as a whole is alerted to a
> less than healthful state.
Not usually. Most of the responses you see during disease are your
body directly trying to rid itself of the pest. Temperature (change
environment, speed up metabolism), inflamation (attract more
white blood cells to the infected areas), coughing (trying to get rid of
debris resulting from engulfed and immobilized invaders), etc.
The aspect of our genetics that is designed to minimize transmission
is our pheromones. You get attracted to people with different
pheromones to allow immune system differences to prevent the spread
of "immune-type" adapted diseases. [Side note to Damien -- perhaps
the problem is that all the Aussies have similar pheromones and so
it is difficult for those inter-personal passions to take control?
I'd suggest a move to Singapore or Hong Kong for some gene pool
mixing...]
>
> Re: HIV, Herpes, etc.
>
It is generally considered true in microbiology that a very virulent
(rapidly spreading, causing high rates of death) organism is a new
entry and highly maladapted. The best organisms, esp. viruses are
those that evolve a stealth strategy. Over time they evolve decreased
pathology which promotes extended transmission. Thus, disease
producing organisms "attenuate" so as to become relatively unnoticed
guests rather than annoyances to be thrown out of your house.
Robert
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