Actually humans are still evolving. However, the way it happens is politically incorrect. Raising the issue will often yield with a bunch of misogynist accusation, etc. Often opinions about this tend to be censored, etc.

Naturally, as in many species, certain individuals have higher probability to reproduce.

1. Some males have more resources and can afford more children.
2. More attractive women can aim for such males and produce more grandchildren.
3. Some males can simply attract more women. Women in humans prefer the rich.

In all countries, including, if not specially, western civilization this advantage is “balanced out”