So has war
The strongest are sent off to die, while those not fit for service stay behind, couple this with modern medicine, and the effects are very grave. Now we have the chance to begin to undue the damage that we've been inflicting upon ourselves for centuries.
I think that the movie Gattica was a great movie, and that it shows the way things could be in another several decades. Anyone will be able to have kids, but with genetic screening and therapy, they'll be the best that they can be. After several generations of this "weed and seed" approach, our descendants will be the inheritors of a much stronger and healthier genome.