Ancient human fossils link First Americans to Europe and Western Asia

Although it's generally accepted that First Americans migrated from Siberia, roughly 14-15 thousands of years ago, it's still not exactly clear to which 'Old World' population they can trace their genetic roots. Now, new DNA evidence from two ancient skeletons found in Siberia suggest that they may be closely linked to western Eurasia.

Studies have found that modern day Native Americans have genetic ties to both East Asia and western Eurasia (collectively Europe and Western Asia), however it's commonly thought that the western Eurasian ties came from fairly recently — after European expeditions crossed the Atlantic and 'discovered' the New World. A study of DNA samples from two skeletons unearthed in south-central Siberia, one dated at 24,000 years old and another at 17,000 years ago, have questioned those assumptions, though. The researchers found that both have very similar genetic lineage to each other, and both show genetic links to both modern day Eurasians and to Native Americans, but no close link to East Asians. They also estimate that modern day Native Americans have between 14 and 38 percent of their genetic ancestry from these ancient people.

Until now, there's been a common assumption that ancient peoples trekked from Eurasia into East Asia, and then migrated north from there into Siberia and across the Beringia land bridge to Alaska. However, with no close genetic link to East Asia, according to the researchers, this suggests "that populations related to contemporary western Eurasians had a more north-easterly distribution 24,000 years ago than commonly thought."

Dr. Kelly Graf, who is one of the co-authors of the study, talks about the findings in this video from Texas A&M University:

[ More Geekquinox: Dinosaur fossil damaged in Second World War recreated with 3D printer ]

Since there are only two individual genetic samples contributing to this study, more research is obviously needed before any conclusive arguments can be made.

"Though our results cannot speak directly to this debate, they do indicate Native American ancestors could have been in Beringia — extreme northeastern Russia and Alaska — any time after 24,000 years ago and therefore could have colonized Alaska and the Americas much earlier than 14,500 years ago, the age suggested by the archaeological record," Dr. Graf said in a statement.

"What we need to do is continue searching for earlier sites and additional clues to piece together this very big puzzle," she added.

(Image courtesy: State Hermitage Museum in Russia)

Geek out with the latest in science and weather.
Follow @ygeekquinox on Twitter!