Tamed or farmed?: Prehistoric cave paintings, such as this example from France's Lascaux Cave, show a long relationship between humans and horses.
So perhaps, Levine suggests, it was used for a few animals kept almost like pets. "It's very easy to capture foals once the mother's been killed." That's a lot different from true domestication, she says, which involves the more difficult task of breeding animals and
raising them from birth.
Still, the manure isn't the only indication that all of those thousands of bones came from domestic animals. Also revealing are the ages of the slaughtered animals, although the conclusions drawn from this information differ wildly, depending on whom you speak to.
"Between 30 and 50 per cent were killed young, which indicates culling," Olsen says. "That's standard in horse domestication."
According to Levine, however: "If you're raising them for meat, you kill them around age three or four." Instead, from her perspective, the Botai excavations reveal an age structure similar to that seen in wild horse herds, suggesting that the Botai engaged in hunting techniques in which entire bands of horses were killed at once.
But Olsen has several strong counters. First of all, she says, some of the horses, particularly stallions, would have been spared from early slaughter and used as steeds. Since they would have lived to much older ages, that skews the age distribution of the bones.
More importantly, Olsen says, the very size of the Botai villages indicates that they were raising horses, rather than hunting them. With at least 160 families living in a small area, subsisting largely on horses, hunting would quickly have depleted the nearby herds. And if the Botai were a hunting culture, she adds, why on Earth didn't they hunt other animals, in addition to horses?
Still more clues come from the manner in which the Botai made their stone tools. Without beasts of burden, it would have been far more convenient to make tools at the flint quarry, rather than lugging hunks of rock back home.
"But they brought in big chunks and made tools," Olsen says. "That indicates pack horses."
Still, none of this, even the presence of phosphates, constitutes proof. "We're talking about lots of different types of indirect evidence," Levine says. "It doesn't prove domestication; it's just interesting and possibly points in that direction."
The ancient animal pen, however, may contain additional secrets. In another unpublished find, Olsen has learned that its soil is 10 times saltier than the surrounding soil. The probable source: urine, presumably from horses. Chemists are also analysing pottery fragments in the hope of finding fat traces from mare's milk. "That will really be the smoking gun," she says. "You don't want to milk a wild mare."
Meanwhile the quest for the earliest site of horse domestication continues. Ancient as their activities were, Olsen doesn't believe the Botai were the first to domesticate horses – they are merely the earliest we can crudely detect with archaeology. "What is the chance that you find the first [example] of anything?" she says.
Read the timeline of domestication that goes with this feature here.
Richard A. Lovett is a contributing editor of Cosmos, based in Portland, Oregon.
