[Dragaera] Breaking the Cycle - Genetic Purity

[Maximilian Wilson]

On 8/29/06, Philip Hart <philiph at slac.stanford.edu> wrote:
>
> 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.

Yes, of course. Cochran has also looked at certain neurological,
genetically-recessive, diseases which are prevalent among the
Ashkenzai Jews and found links between heterozygosity and increased
IQ. There's even a *dominant* disease (torsion dystonia) which appears
to increase IQ by most of a standard devation, which is maybe what
you'd expect if you're paying the price to have a dominant genetic
disease.

-M.

-- 
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Be witty if you can,
But be cheerful if it kills you.