( ne of the last places on Earth where Pl...)New evidence of early horse domestication

Because they were domesticated, the horses supplied meat year-round and vitamin-rich mare's milk from spring through fall. "No one in their right mind would try to milk a wild mare," said Olsen.

There is also evidence that the Botai were carrying a lot of heavy material, like rocks and large skulls, over long distances. That is a lot more practical and explicable if they used pack horses.

Later people of the same region adopted shepherding and cattle raising, said Olsen. That created a more nomadic culture, since sheep and cattle are not well suited for sub-zero climates and therefore needed to be taken south in winter. The tradeoff, she says, was that cows and sheep give far fattier milk year round, which can be made into yogurt and cheese. Sheep also provide wool.

Kazakh people today still eat horsemeat. They were forced to abandon their nomadic lifestyle during the Soviet era and have returned to small village pastoralism, Olsen says.