They found evidence of a varied diet, with signs found for plant oils and animal fat. The most common fats were of animal origin, Dunne said, with some deriving from flesh and others from milk. The most dairy-fat rich pottery shards came from the same time periods when more cattle bones are found in the cave layers, the researchers reported today (June 20) in the journal Nature.
By looking at variations in the carbon molecules in these preserved fats, the researchers were able to get an idea of what kind of plants the cattle were eating. They found their diets varied between so-called C3, or woody plants, and C4 plants, which include grasses grains and dry-weather plants. (C3 and C4 refer to the type of photosynthesis these plants use.)
That fits with the archaeological understanding of this early herding civilization as moving between seasonal camps, Dunne said. [Album: Faces of a Threatened Tribe]
"It suggests that they were moving between summer and winter camps and eating different plants at one place than another, so this all ties together very nicely," she said.
No one has ever before looked for evidence of dairy farming in these herding tribes, Dunne said, but the new findings help explain how humans got their taste for milk. People first settled down to an agricultural lifestyle in the Near East about 8,000 or 9,000 years ago, she said. Soon after, they took up dairy farming. The milk habit then spread across Europe in fits and starts.
At the same time, though, people were also migrating from the Near East into what is now Egypt and other parts of Africa, Dunne said. This movement spread dairying to north Africans, who were previously settled hunter-gatherers and fishermen. As new immigrants moved in with cattle, these native people would have quickly seen the benefits of "marvelous big hunks of food on the hoof," Dunne said.