5500-year-old horse teeth, like this one, found at Botai settlements show distinct parallel wear lines typical of bridled horses (Image: courtesy of AAAS)

High up in the steppes of Kazakhstan is where it may have first happened: a human decided to climb atop a horse instead of killing it for meat. The act seems trivial today, but nearly 5500 years ago it would have been revolutionary.

“Horse domestication was a landmark moment, a bit like the invention of the wheel,” says Alan Outram of the University of Exeter, UK.

By domesticating horses, humans created the first form of land transportation, vastly expanded the region within which goods could be traded and wars waged, and spread culture over huge swathes of land.


Outram and colleagues have now found the world’s first “horse farms”, in Kasakhstan’s ancient Botai settlements. The sites date back to 3500 BC, pushing back the domestication of horses by 1000 years.

The researchers studied horse remains from four settlements in the steppes of north-central Kazakhstan. Before the Botai built villages dug out of the ground, the region was home to nomadic hunter gatherers that followed and killed wild herds of horses. What made them suddenly settle in villages, the largest of which comprises some 100 houses, is something of a mystery.

Dental wear and tear

More than 90% of bones in Botai settlements are horse bones, far outnumbering human remains. The researchers found their structure closely related to domesticated Bronze Age horses.

Outram recruited the help of Robin Bendrey, of France’s Museum of Natural History. After years spent poring over horse teeth, Bendrey had found that bits and bridles leave distinct deep, parallel wear lines on the animals’ teeth. The wearing can take away the enamel and dig into the dentine, and appears only on the pre-molars, in places where wild horses show no sign of wear and tear.

Bendrey found bit wear marks on the horse teeth collected from Botai settlements, and concluded that the animals must have been domesticated.

There is no way of saying for sure whether or not the Botai rode their horses, says Outram, but he believes it is very likely. For starters, stone tools found at the settlements are not made from locally-sourced stone, so it’s likely the people travelled great distances.

The Botai, whose ancestors hunted wild horses, probably also kept the animals for food. Cattle cannot graze under snow and would not have survived the steppe’s harsh winters. There is also no archaeological evidence of agriculture, making it unlikely that the horses were used to till fields.

It seems they did milk them, though. Modern day Kazakhs drink a fermented milk drink called “koumiss” and Outram and his colleagues found traces of horse milk fat on Botai pottery vessels.

Shifted world view

“Domestication is a major shift in mentality and world view,” says Outram. “Before, people go out into world to collect things, and their only interest in animals is to kill them. After, they move into a production mode, and are interested in taking care of animals and their progeny.”

The shift is also accompanied by new social power. “Hunter-gatherer societies tend to be egalitarian. But as soon as you domesticate animals, the question becomes ‘who owns them?'” Answering that – establishing people who own more or less – creates a social hierarchy.

Outram now wants to look deeper into the site – literally. He has recently completed a geophysical survey to detect building structures beneath the steppe’s surface, and will analyse these in an attempt to understand more about Botai society.

In the meantime, one mystery may have just been solved. Anthropologists have long wondered what made the Botai settle down. Learning to domesticate horses, possibly from distant groups that had domesticated cows, may have meant they no longer had to chase after their food all the year round.

Journal reference: Science (DOI: 10.1126/science.1168594, in press)