Science: Botai Culture Was Probably First to Domesticate Horses

A Botai stallion's lower second premolar (mesial edge), displaying a clear parallel-sided band of bit wear that penetrates through the cementum and enamel. This morphology and depth of wear occur only in bridled animals.

[Image © of Science/AAAS]

Three new pieces of evidence solidify the Botai culture, located in what is now Northern Kazakhstan from 5700 to 5100 years ago, as one of the first in the world to domesticate wild horses, researchers say.

The domestication of wild horses changed the course of human history, and revolutionized the way human beings traveled, communicated, and waged war with each other. But, despite the significance of this accomplishment, scientists have found it extremely difficult to pinpoint specific historical events or processes to mark the occasion.

The new evidence bolstering the Botai culture as the world's first horse tamers is published in the 6 March 2009 issue of the journal Science.

Lead author Alan Outram from the Department of Archaeology at the University of Exeter, along with colleagues, first studied the bone structures of ancient Botai horses and compared them to other horse fossils from the same region and time period. They found that the bones of the Botai horses, particularly those in the horses' feet, resembled the bones of other Bronze Age domestic horses that appeared later on. The bones of the Botai horses did not resemble those of the Paleolithic wild horses from the same region. This presents one line of evidence suggesting that the Botai domesticated their horses before anyone else.

Looking at the skulls of the Botai horses, the researchers noticed another indication that the horses were tamed. Careful observation of the ancient animals' teeth revealed physical markings that could only have been made from human-made bits and bridles. These marking on the horses' teeth had worn away the enamel, exposing the underlying dentine, and such severe wear only occurs in bitted or bridled animals. This means that at least some Botai horses were harnessed and ridden. Outram and his colleagues report that five out of 15 Botai horse skulls they studied were scarred with the markings.

Finally, the researchers used isotope data from Botai pottery fragments to identify fat from horse milk that was stored in those ancient containers. The specific deuterium isotope that they used in their analysis would vary from season to season in an area like the Eurasian Steppe where the Botai culture dwelled, so Outram and his team were even able to specify that the horses were milked during the summer months.

A mare being milked in a traditional village in northern Kazakhstan.

[Image courtesy of Alan K. Outram]

This finding in particular seemed to excite the researchers most. The evidence that the Botai stored horse milk pottery essentially confirms that some Botai horses were domesticated. But it also raises many questions about how the strategy of milking animals for nourishment came about, evolutionarily.

In the authors' conclusion, they write: "The fact that horse milking existed in a region remote from... the 'Fertile Crescent' and in an area seemingly devoid of domestic ruminants indicates that the evolution of strategies for exploiting animals for their milk was not contingent on the adoption of the conventional 'agricultural package,' as it appears to have developed independently in the Botai region."

All of these archaeological puzzle pieces provide evidence of the earliest domestication event on record so far. Continued research will reveal more about the ancient Botai people, and eventually, it may also reveal even earlier evidence of horse domestication somewhere else in the world.

Brandon Bryn

6 March 2009