[extropy-chat] magic johnson, aids, longevity ...

[Alejandro Dubrovsky]

On Mon, 2006-04-17 at 05:28 -0500, Robert Bradbury wrote:

>         
>         Because creating stronger selection pressures increases the
>         rate of
>         evolution, in this case, of resistant strains.
> 
> A nice succinct answer.
> 

And wrong, I think, in this case.  If you want to train a GA to do
something very tricky, a standard thing to do is to split the problem
into easier problems and you feed it to the population one by one, so
that at each step you get a large-sized population having a crack at the
next not-so-large problem.  Giving bacteria one anti-biotic problem at a
time seems like helping them to me.

If you've got a population m of bacteria trying to solve anti-biotics J
and K, which need a mutation with probability 1/j and 1/k respectively
of arising, where j and k on the order of the product of m * average
mutations per bacteria, then the probability of one of the bacteria 
having a mutation for either drug is quite high, but the probability for
any of the bacteria having both is almost zero (as long as bacterial
mutations look anything like normal/binomial distributions).

(please do supply references to studies showing otherwise if you know of
them so that it will clarify why doctors continue this strange practice)