Providing the strongest evidence yet that humans are still evolving, researchers have detected some 700 regions of the human genome where genes appear to have been reshaped by natural selection, a principal force of evolution, within the last 5,000 to 15,000 years. The genes that show this evolutionary change include some responsible for the senses of taste and smell, digestion, bone structure, skin color and brain function. Many of these instances of selection may reflect the pressures that came to bear as people abandoned their hunting and gathering way of life for settlement and agriculture, a transition well under way in Europe and East Asia some 5,000 years ago. Under natural selection, beneficial genes become more common in a population as their owners have more progeny. Three populations were studied, Africans, East Asians and Europeans. In each, a mostly different set of genes had been favored by natural selection. The selected genes, which affect skin color, hair texture and bone structure, may underlie the present-day differences in racial appearance. The study of selected genes may help reconstruct many crucial events in the human past. It may also help physical anthropologists explain why people over the […]