Let's avoid the religious debate and assume Evolution is real
The prime drivers of evolution are
1) Random gene mutations
2) Survival of the Fittest/Natural Selection
The issue I see is that humans actively fight against natural selection/survival of the fittest...
We have hospitals where we treat down's syndrome, cancer, epilepsy, and all forms of mental and physical retardation
Without intervention, these "bad genes" would die and leave the gene pool... but, we keep these people alive, to pass on "bad genes" to the next generation
I know it sounds callous, etc., but it seems like a stupid idea to fill the gene pool with "bad genes", rather than let nature take it's course and kill off the poor bastards who drew the short straw
If a dog breeder had a dog with an obvious deformity, it would not use the dog for breeding purposes... that would be stupid to contaminate the breed's gene pool
Nazis agree with you.
But who decide what genes are bad or good? In Third Reich only nazis decide it! May be mankind with 2 head can be more succesful in future? Or people with stone skin? We can't know it. So I prefer that mother-nature decide it then some fanatics...