17 August 2008
Stone Age milk use began 2,000 years earlier
Prehistoric humans consumed milk at least 8,500 years ago—up to 2,000 years earlier than previously thought — new discoveries of the the earliest known milk containers suggest. The find shows that the culinary breakthrough of using animal milk was first developed by cow herders in northwest Turkey. The first milk users, though, are not thought to have been milk drinkers—but butter, yogurt, or cheese eaters.
"It's the earliest direct evidence for milk use anywhere," said lead study author Richard Evershed, professor of biogeochemistry at the University of Bristol, United Kingdom. Evershed and his team analyzed more than 2,200 ceramic vessels from late Stone Age sites across Turkey, southeastern Europe, and the Middle East. Evidence for milk fats—as opposed to meat fats—showed up clearly on unglazed pots dating back to 6500 BCE from the Sea of Marmara region. Ancient animal bones at the site also revealed the dairy livestock used there were cattle, rather than goats or sheep. "It's where you start to see milk really being used," Evershed said. "As you go to other locations, the cattle evidence is much weaker, and the milk residues also show up much more weakly." The traces of milk fats can survive on the pottery, even after being buried for thousands of years, because the fats are hydrophobic, so they don't dissolve in water, and they are produced in large amounts.
Previously, experts argued that sheep and goats kick-started dairy production, Evershed said. "This [study] shows that if you get into serious milk consumption, where you're using pottery and preparing your milk, it's really related to cattle suddenly coming onstream," he said. Northwest Turkey probably provided the right environmental conditions for cattle herding, having 'higher rainfall and greener grazing' than other regions where farming began, the study team wrote. The development of pottery and dairy products such as butter, yogurt, and cheese seem to go hand in hand, Evershed said.
While other recent research based on bone remains of slaughtered livestock suggests even earlier use of cows for dairy products, the new evidence is less open to doubt, Joachim Burger of the Institute of Archaeology at Johannes Gutenberg University Mainz (Germany) said. Burger's own research indicates that raw milk wasn't part of the late Stone Age diet, since adults were uniformly lactose intolerant as recently as 7,000 years ago. However an inability to drink milk wasn't necessarily a barrier to earlier dairy consumption, as lactose breaks down during processing, Burger said. Even so, raw milk probably wasn't consumed until some 1,000 to 2,000 years later, he said. By then dairy farming had spread into Europe, where it met a genetic mutation that allowed humans to digest lactose into adulthood, he added.
Lead study author Evershed said dairy production would have been a key driver in human civilization: It provided a reliable, year-round source of nourishment and allowed a key staple to be produced on a large scale. In lactose-tolerant central and northern Europe, dairy farming became "the basis of our culture," according to Burger of Mainz. Dairy products gave lactose-tolerant people, he said, a major advantage over fellow Europeans.
Sources: National Geographic News, Live Science (6 August 2008)