Horses originated in America and reached Europe through China, fossil DNA reveals

Everyone knows the story: when Spanish conquistadors rode into the New World, Native Americans were stunned by a towering, four-legged creature they had never seen before. Horses, the theory goes, were a European import to the Americas.

But a new fossil DNA study indicates that horses actually originated in North America millions of years ago and only reached Europe thanks to an unexpected genetic middleman in China.

An extinct lineage called the Dalian horse, once dismissed as a local oddity in northeastern China, had a distinctive American ancestry and passed it on to ancient horse populations in Siberia, the researchers say.

That gene flow means the bloodlines that later gave rise to modern European horses picked up their American roots via this Chinese crossroads.

“Dalian horses likely served as one route through which North American-related genetic ancestry entered Northeast Eurasian horse populations,” the researchers wrote.

“[The] findings position the Dalian horse as a key lineage for elucidating late Pleistocene equid evolution in Northeast Asia and the dynamics of trans-Beringian genetic exchange.”