Horses domesticated 1,000 years earlier than previously thought

6 March 2009 by Tamera Jones

The earliest known evidence of horse domestication has been unearthed in Kazakhstan in central Asia. New research suggests the Botai Culture have been riding horses and using their milk for the last 5,500 years.

Wild horses

Wild horses on the plains of Kazakhstan

This is around 2,000 years before horses were domesticated in Europe and 1,000 years earlier than previously thought for Kazakhstan.

The findings could point to the beginnings of horse domestication and the origins of the horse breeds we know today. Archaeologists argue that it was the domestication of horses that opened the way to trade, warfare, transportation, agriculture and many other aspects of human civilisation.

Horses were soon being harnessed to chariots and then later carried archers into battle. Horses played a major role in the expansion of the Roman Empire, helped secure the 13th century conquest of China by the Mongols and were used in the First World War to move artillery.

Three lines of evidence

Previous research traced horse domestication back to around 4,500 years ago. But the new analysis - published today in the American journal Science - used three independent lines of evidence to show that humans and horses lived in close association earlier than this. The study, led by Dr Alan Outram from the University of Exeter and Professor Richard Evershed at the University of Bristol, found that horses were not just used for riding. They were also used for food, including milk.

This is significant because it changes our understanding of how these early societies developed. The domestication of horses is known to have had immense social and economic significance, advancing communications, transport, food production and warfare.

- Dr Alan Outram, University of Exeter

Outram's team - including researchers from the University of Winchester, the Carnegie Museum of Natural History in Pittsburgh, USA and Kokshetau University in Kazakhstan - studied material from the Eneolithic site of Botai in Northern Kazakhstan.

The researchers looked for a strip of wear on horses' front teeth for evidence of 'bit damage' - caused by horses being harnessed or bridled. They also wanted to see if the lower jaw bone has changed as a result of being harnessed. Their results showed the horses had been harnessed, which raises the possibility they were also ridden.

Using a new method of fat residue analysis that exploits differences in carbon and hydrogen isotopes, they found traces of fat from horses' milk on Botai pottery. Mares' milk is still drunk in Kazakhstan, a country in which horse traditions run deep. The milk is usually fermented into an alcoholic drink called 'koumiss'. While it was known that koumiss has been produced for centuries, the study shows it dates back to the earliest horse herders. "This is the first time anybody has been able to show such early horse milking," says Outram.

Horses selected for breeding

The team, funded by the Natural Environment Research Council, also looked at the shape of the lower leg bones in the horses found at Botai. They discovered slender bones that are similar to bones from horses living in the Bronze Age - a time when horses were widely used by people. Bones from wild horses from the same region from the Pleistocene era are much stockier. This may mean people selected wild horses for their physical attributes, which were then exaggerated through breeding.

Outram's results show clearly that people in Kazakhstan were using horses much earlier than originally thought. "The three different techniques all tell the same story. They really seal it," says Outram. "This is significant because it changes our understanding of how these early societies developed. The domestication of horses is known to have had immense social and economic significance, advancing communications, transport, food production and warfare," he adds.

The steppe zones, east of the Ural Mountains of northern Kazakhstan, were a prime habitat for wild horses thousands of years ago. Indigenous cultures hunted wild horses for generations. They fashioned tools from horse bones and turned horse hides into thongs. Horses were used to haul goods.

Throughout most of their history, the Kazakh people lived nomadic lives. But at some point they started settling down. The reason for this could be horse domestication.

Outram and his team's research suggests that horses were domesticated in preference to cattle, sheep and goats, which were a later addition to the prehistoric economies of the region. "Horses can live in a wide variety of grasslands and are used to very cold winters. They can graze, whereas cattle need fodder," he adds. "These people didn't have other domestic animals at this time."