Indo-European languages are native to populations from Ireland to Afghanistan and India and, in historical times, to the Tarim Basin in China. This spread occurred within a few thousand years carried by people who were mostly horse pastoralists and who carried a mutant regulator of the lactase gene so that they could as adults digest milk sugar. Henry Harpending, University of Utah, discusses how individuals with such lactase persistence are able to extract 40% more calories from milk, while others usually ferment away the milk sugar lactose by making cheese or yogurt. While superior technology of invaders can be adapted by indigenous people, such a biological advantage cannot be copied. Series: "CARTA - Center for Academic Research and Training in Anthropogeny" [Science] [Show ID: 24112]