This is the first evidence that I’m aware of for genetic adaptation in a subgroup of modern humans.

The Bajau people of Southeast Asia, known as Sea Nomads, spend their whole lives at sea, working eight-hour diving shifts with traditional equipment and short breaks to catch fish and shellfish for their families. In a study published April 19 in the journal Cell, researchers report that the extraordinary diving abilities of the Bajau may be thanks in part to their unusually large spleens. The adaptation, the researchers say, is a rare example of natural selection in modern humans — and one that could provide medically relevant insight into how humans manage acute hypoxia.

https://www.sciencedaily.com/releases/2018/04/180419131128.htm