Wild Horses Can't Drag Me Away Because They Don't Exist, Genetic Analysis Finds

Genomic research has dramatically re-written what we know about the history of horses. Most importantly—wild horses no longer exist.

Before a study published Thursday in the journal Science, biologists believed that Przewalski's horses were the only purely wild horses left alive in the world, the blood running through their veins untainted by a history of domestication. They also believed that the Botai horse, an ancient breed named for the Botai people of modern-day Kazakhstan, was the genetic father of all domestic horses today.

To investigate these claims, scientists at the University of Exeter and the French National Center for Scientific Research did a genomic analysis of 88 ancient and modern horses and mapped them out. They found that neither of the assumptions about Botai and Przewalski's horses were true.

Archaeologists had analyzed evidence of horsemanship at ancient Botai sites and found that Botai people rode horses, used bridles with bits, drank the milk of the horses and ate their meat. They also kept multiple horses in corrals, demonstrating that keeping, riding and eating domestic horses was an integral part of the Botai culture.

Genetic evidence shows that some Botai horses escaped or were set free, and ultimately gave rise to Przewalski's horses, also known as Takhis. The researchers also found that the earliest Przewalski's horses had spotted, Appaloosa-like coats, a trait that may have been bred into Botai horses because it looks cool. The takhis eventually became the tan, stocky animals we know today. But as they are descendants of domestic Botai horses, Przewalski's horses can no longer be considered "the last wild horses."

Instead, like the American Mustang and the French Camargue horses, takhis are technically "feral," like a feral neighborhood cat or dog. Still, some colloquially describe free-roaming horses as "wild," which sounds better than "feral," and it's common enough in the lexicon that saying "wild" isn't entirely inaccurate among non-scientists.

Przewalski's horses are endangered, and were once considered extinct in the wild because interbreeding with truly domestic horses diluted their populations. However, some zoos kept the pure animals, and in the 1960's conservationists made an effort to breed the last remaining animals and reintroduce them to nature.

"Ironically, we used to think that the endangered population of Przewalski's horses should be preserved as the last wild horses in the planet," Charleen Gaunitz, one of the Ph.D. students who carried out the experiment, said in a press release. "We now find that they must be preserved as the closest descent of the earliest domestic horses."