[badosu]

It is required some process of natural selection for mutations to be selected against, do we know how this occurs with the modern homo sapiens?

[MrVandemar]

We have plenty of modern day selection pressure. Watch the first 2 minutes of Idiocracy.

[pfdietz]

Unless you think our ancestral biology is perfectly adapted to the modern world, evolution will be acting. Indeed, evolution is probably occurring on humanity at a breakneck pace right now, because our environment has changed so radically.