Africans are more genetically diverse than the rest of the world combined.
Modern humans evolved in Africa about 200,000 years ago, and began moving out of the continent into Eurasia and beyond about 60,000 years ago.
It explains why the further away from Africa you go, the less genetically diverse populations are; it means that two Africans might have less in common – genetically – than an African and a European.
Although the word “mutation” conjures up the image of a freakish, perhaps even grotesque abnormality, the word is neutral in science-speak, simply denoting a permanent change in the genetic sequence of an individual.
Sometimes, mutations prove to be advantageous. For example, athletes of primarily West African descent have excelled notably in short-distance running events.
Jon Entine, in his book “Taboo: Why Black Athletes Dominate Sports and Why We’re Afraid to Talk About It” says that athletes of primarily West African descent—which includes the majority of U.S. blacks—hold all but six of the 500 best times in the 100-metre race, “the purest measure of running speed,” says Entine, whose book set off a fiery debate on the subject.
Sprinters, as opposed to marathoners, have mostly type II “fast-twitch” muscle fibers, which hold lots of sugar as well as enzymes that burn fuel in the absence of oxygen, meaning they can perform anaerobically at very high power output. But the jury is still out on Africans’ evolutionary advantages for sport, and for good reason.