Actually, as was pointed out to me very recently by a scientist studying another genetic illness, for a recessive gene illness to survive evolution, all that is necessary is for the carriers to survive long enough to reproduce.  Many genetic illnesses don't present until after reproductive age.
   
  (Genetic illness is also common in veterinary medicine).
   
  PCOS begs the question because it does cause infertility - in fact is the leading cause of infertility in females in the US and possibly present in as many as one in fifteen women in the US.  But now researchers are looking at the second trimester as the time of development for this particular disease.  This would imply that a dietary hypothesis for the individual woman suffering from the illness is false - although it does not eliminate a dietary hypothesis for the mother of the PCOS patient.
   
  gale
  

Ashley Moran <[log in to unmask]> wrote:
  On Feb 22, 2008, at 7:04 pm, Gale wrote:

> There is no question that PCOS (poly-cystic ovarian syndrome) has a 
> genetic cause and probably only a minute (if any) environmental 
> factor link

If this was true, a significant number of women during the paleolithic 
would have suffered from PCOS. This I just don't believe. Loren 
Cordain thinks it is a side effect of insulin resistance. Just 
because it can't be fully corrected by an improved diet doesn't mean 
it wasn't caused by the faulty diet in the beginning.

Remember: ALL non-infectious diseases are ultimately genetic. 
Something in the organism has to respond to the environment. Either 
the organism responds in a way that is beneficial for its survival, or 
in a way that makes it fall ill. The organism's genes have no concept 
of either outcome - either the animal survives to produce offspring or 
it doesn't.

Common sense says that the number of purely genetic illnesses must be 
pretty insignificant, or individuals carrying the disadvantageous 
genes would have been weeded out long ago. The only reason I can 
think that humans may be more susceptible to genetic disease than 
other species is that we went through a population bottle neck in the 
relatively recent past. But maybe other similar species have too - I 
have no idea. That's something I'd like to know more about, but I'm 
no biologist.

Ashley



       
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