On Feb 22, 2008, at 7:32 pm, Robert Kesterson wrote:
> Not necessarily.  A genetic disease that strikes in middle age  
> doesn't prevent procreation before it strikes.

I've heard this argument but I'm still unconvinced.  Humans live in  
family groups, so something that kills off people in their middle age  
will disadvantage their children.  The impact wouldn't be as great but  
would still be a bias against that gene line.

Someone must have done some statistical modelling of this surely.

Ashley