Why does natural selection no longer apply to humans?

Because wealth is what ensures survival: they say wealth is attained by those who are the smartest, with the most intelligence, and so intelligence would be the trait that ensures survival; those who do not have intelligence will soon become extinct for they will not be able to survive: but with connections anyone can make money. Can connections be the desired trait that in ensuring wealth ensures survival? Nietzsche says that we send the strong off to war and so only the weak are left, it is they who survive. But in a world where morality is operative at all times, the pity that resentiment demands, the care of the strong for the weak, the poor, in the name of Christianity ensures everyone's survival: and affirmative action! We help those who have fallen down back to their feet: then anyone can try and thats all it takes to make money, to survive. Effort, intelligence and connections are those dominant traits that ensure survival, those without them will be left behind, unless we keep picking them up. Selection becomes artificial back rubbing, who'll work the hardest and who's the brightest are the ones who'll succeed. But do you need money to have children?