Tamed or farmed?: Prehistoric cave paintings, such as this example from France's Lascaux Cave, show a long relationship between humans and horses.
ANCIENT CAVE DRAWINGS show people have long been captivated by wild horses. But at some stage, thousands of years ago, someone realised that these powerful, majestic creatures needn't always be wild.
Perhaps this brainstorm struck only once, or perhaps in several different places. Genetic studies have found that while modern horses appear to originate from a large number of mares, they are descended from a much more limited number of stallions.
It's possible that horses were domesticated by a single clever tribe, and later on others captured additional wild mares to mate with their stallions.
Sandra Olsen, an archaeologist at the Carnegie Museum of Natural History in Pittsburgh, USA, believes this process began somewhere on the Eurasian steppes.
For more than a decade, she's been excavating villages from the Botai culture of northern Kazakhstan, looking for evidence that 5,600 years ago, they were already using horses for meat, tools, and transportation.
In one village, her team has recovered more than 300,000 bone fragments – more than 99 per cent from horses. Marks on the bones indicate the horses were butchered for meat.
But were they domestic animals raised for slaughter, or wild ones, hunted? It's hard to prove either way, because primitive horse tack – a sure-fire sign of domestication – was likely made of leather that rotted away long ago.
But tack and bones aren't the only things archaeologists have discovered. At the Botai village of Krasnyi Yar, Olsen's team has found an array of holes made by ancient posts that looks suspiciously like the remains of a corral.
And in an as yet unpublished find, her team thinks they've discovered traces of horse manure in the soil of the circular enclosure. These traces take the form of high concentrations of phosphates – a nutrient contained in animal manure.
By comparison, levels of nitrate, another nutrient found in manure, were not elevated within the paddock. This makes sense, because nitrates easily leach out of soil in rainstorms, or are decomposed by bacteria.
So the lack of nitrates indicates that the phosphates aren't recent contaminants from a later corral built on the site. "It suggests we've got old stuff," says team member Rosemary Capo, a professor at the University of Pittsburgh.
But Marsha Levine of the University of Cambridge, U.K., thinks the circular structure was a holding pen for wild animals, corralled for subsequent slaughter. "American Indians used to chase [wild] horses into a corral," she says. Chasing wild horses into a corral in the middle of a village, however, might have been risky.
Read the timeline of domestication that goes with this feature here.
