It is in response to recent environmental changes, several human genes evolved! The recently evolved ones are those involved in metabolism, skin pigmentation, brain function and reproduction. This is what a new study of natural selection in the human genome claims.
The researchers identified 700 genes. It is during the divergence of humans and chimpanzees millions of years ago, many of these, especially those involved in smelling, fertility, and reproduction are also suspected of having undergone natural selection.
Via: New Scientist