[Dragaera] Breaking the Cycle - Genetic Purity

[Philip Hart]

On Mon, 28 Aug 2006 Gaertk at aol.com wrote:

> "Maximilian Wilson" <wilson.max at gmail.com> writes:
>
> >[Cochran's idea is that if you take evolution seriously, not many
> >diseases can be genetic in origin because they'd quickly get bred out
> >of the gene pool;

Hard to say what "not many" means, but there are diseases like sickle cell
anaemia or CF or Tay-Sachs which are (may be?) the result of heterozygous
advantage in an adverse environment (malaria, cholera, TB) - having one
incompletely recessive allele may be helpful (or mostly helpful), but some
get two.


Also, we haven't been under normal natural selection pressure for a
while...