Throughout their history, horses have been interbred, traded between populations of people, and moved across continents. All of this makes their genetic history hard to follow. Moreover, the wild ancestor of horses, Equus ferus, is extinct, complicating researchers’ efforts to compare the genetics of domestic animals with wild ones. Previous research nailed down a broad area—the Eurasian Steppe, which stretches from Hungary and Romania through Mongolia—as the region where horses originated and were domesticated. But earlier genetic studies relied mostly on mitochondrial DNA, which is inherited only from a mother, to try to understand horses’ evolutionary history.
“The problem was that there was a lot of diversity in the mitochondrial DNA,” says biologist Vera Warmuth of the University of Cambridge in the United Kingdom, the first author of the new study. And the diversity didn’t group the horses into their breed or place of origin. “Every horse breed has almost all the mitochondrial lineages represented,” she says.
Story: Sarah C. P. Williams, Science Now | Photo: Vera Warmuth