I think there IS still natural selection in humans, and it is relatively new: birth control.
I suspect that those with religious/conservative beliefs who will not take morning-after or birth control pills AND those irresponsible people who theoretically might – but didn’t think about it until too late – will be two groups that increase their numbers while more responsible/fore-thinking people and those without moral objection to the pill (or perhaps WITH moral objection to overpopulating the planet) will be more likely to cap their number of offspring. Yes, this was kinda covered in the movie Idiocracy, but I don’t think it was that far off.