Horses have lived in Siberia since the Late Pleistocene age, so the region’s modern equine populations should have evolved over thousands of years to easily withstand that Arctic climate, right? Actually, no.

An international group of scientists has learned that today’s local Yakutian horse, known for its ability to withstand temperatures dropping below -70°C (-94°F), only arrived in far-east Siberia between the 13th and 15th centuries. That means that in only 800 years, the species showed one of the fastest evolutionary adaptations known in large mammals.

The original Yakutian horse was still alive about 5,000 years ago, approximately the same time as mammoths died out, said Ludovic Orlando, PhD, head of Paleomix Group and curator of cryobank at the Natural History Museum of Denmark’s Centre for GeoGenetics, part of the University of Copenhagen.

The current Yakutian horse was imported within the last millennia from Mongolia and has no genetic links to the ancient original breed, which was likely extinct by the time the new one entered the region, Orlando said. As such, the new Yakutian could not have benefited from 30,000 years of adaptive evolution, as previously suspected. Rather, it became resistant to extremely cold temperatures in record time