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Thursday 5 March 2009

March 6, 2009

Archaeologists find earliest known domestic horses

An international team of archaeologists has uncovered the earliest known evidence of horses being domesticated by humans. The discovery suggests that horses were both ridden and milked. The findings could point to the very beginnings of horse domestication and the origins of the horse breeds we know today. Led by the Universities of Exeter and Bristol (UK), as well as Carnegie Museum of Natural History (USA), the research is published today, March 6, in leading academic journal Science.

The researchers have traced the origins of horse domestication back to the Botai Culture of Kazakhstan circa 5,500 years ago. This is about 1,000 years earlier than thought and about 2,000 years earlier than domestic horses are known to have been in Europe. Their findings strongly suggest that horses were originally domesticated, not just for riding, but also to provide food, including milk.

Through extensive archaeological fieldwork, led by Carnegie Museum of Natural History curator, Dr. Sandra Olsen, and University of Exeter lecturer, Dr. Bruce Bradley, and subsequent analysis using new techniques, the team developed three independent lines of evidence for early horse domestication. Their findings show that in the fourth millennium BC horses in Kazakhstan were being selectively bred for domestic use. They also show horses were being harnessed, possibly for riding, and that people were consuming horse milk. This work builds on previous research by Olsen conducted since 1993 on early horse domestication at Botai sites.

Analysis of ancient bone remains by Dr. Alan Outram and others on the team showed that the horses were similar in shape and size to Bronze Age domestic horses and different from wild horses from the same region. This suggests that people were selecting wild horses for their physical attributes, which were then exaggerated through breeding.

One member of the team, Dr. Robin Bendrey, used a new technique to search for “bit damage” caused by horses being harnessed or bridled. The results showed that horses had indeed been harnessed, suggesting they could have been ridden.

Using a novel method of lipid residue analysis, the researchers at Bristol, Dr. Richard Evershed, Natalie Stear, and David Chivall also analyzed Botai pottery and found traces of fats from horse milk. Mare’s milk is still drunk in Kazakhstan, a country in which horse traditions run deep, and is usually fermented into a slightly alcoholic drink called “koumiss.” While it was known that koumiss had been produced for centuries, this study shows the practice dates back to the very earliest horse herders.

Lead author Dr Alan Outram of the University of Exeter said: “The domestication of horses is known to have had immense social and economic significance, advancing communications, transport, food production and warfare. Our findings indicate that horses were being domesticated about 1,000 years earlier than previously thought. This is significant because it changes our understanding of how these early societies developed.”

Director of the Botai fieldwork, Sandra Olsen, said: “After decades of research by numerous scholars, we have finally identified concrete evidence for the earliest horse domestication. The finding of residues of ancient mare’s milk residues in Botai pottery, in particular, is solid proof that the animal remains from our sites were not derived from wild individuals. This adds to earlier indications of domestication found by our team, including a corral, a preponderance of butchered horse bones, tools for making rawhide thongs for horse tack, manure used for insulation in building materials, and horse sacrifices.”

The steppe zones, east of the Ural Mountains in Northern Kazakhstan, are known to have been a prime habitat for wild horses thousands of years ago. They were a commonly hunted animal. This may have set the stage for horse domestication by providing indigenous cultures with access to plentiful wild herds and the opportunity to gain an intimate knowledge of equine behavior. Horses appear to have been domesticated in this region before adopting a herding economy based upon domestic cattle, sheep and goats. Horses have the advantage of being adapted to severe winters and they are able to graze year round, even through snow. Cattle, sheep and goats need to be to be provided with winter fodder, and were a later addition to the prehistoric economies of the region.

This study was carried out by the Universities of Exeter, Bristol and Winchester (UK), Carnegie Museum of Natural History (Pittsburgh, USA), and Kokshetau University (Kazakhstan) and was supported by the Natural Environment Research Council, British Academy and the United States of America National Science Foundation Grants BCS 0415441 and BCS 9816476.

Carnegie Museum of Natural History, one of the four Carnegie Museums of Pittsburgh, is ranked as one of the top five natural history museums in the country. It maintains, preserves, and interprets an extraordinary collection of 21 million objects and scientific specimens used to broaden understanding of evolution, conservation, and biodiversity. More information is available by calling 412.622.3131 or from the Web site, www.carnegiemnh.org.

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