Anthropologists have long believed that there was a protracted lag between when humans started domesticating cattle for food—about 9,000 years ago—and when they managed to harness the animals to plows and collect their milk. “It’s one thing to keep an animal in a corral and quite another thing to get near enough to milk it,” says University of Bristol chemist Richard Evershed. To get a fix on when the second stage occurred, Evershed pulverized tiny pieces of 2,200 pottery fragments from sites in the Near East to see if they contained traces of dairy fats.
His results, published in August in Nature, hint not only that people made the dairy leap just as soon as they began domesticating herd animals, but that these early “ranchers” were even processing milk and storing it. The study may also help geneticists solve the mystery of where and when people evolved the ability to digest the milk sugar lactose.
To this day, most adults around the world can’t easily digest milk, but those who can may be the progeny of populations in the Near East and southeastern Europe, where Evershed finds the earliest evidence of stored milk. “It’s a very interesting study. Put the two maps on top of each other and you get a coherent pattern,” says geneticist Anders Götherström of Uppsala University in Sweden.