Ancient milk teeth unearthed from Siberia has led to the discovery of a previously unknown population who lived in the region during the last Ice Age.
The DNA from the teeth are dated to more than 31,000 years ago, making it the oldest genetic material ever found in Siberia.
As part of the same wider study, researchers also revealed that another site in Siberia yielded 10,000-year-old human remains found to be genetically related to the Native Americans.
It's the first time close genetic associations to Native Americans have been found outside of the United States.
Ancient North Siberians
Even in modern times, winters in Siberia is a perilous experience. Ancient Siberia is infinitely more treacherous, especially in the middle of an Ice Age.
To fill the gaps on the population that was able to live through the harsh conditions, researchers analyzed the milk teeth from Yana Rhinoceros Horn Site where over 2,500 artifacts have been recovered.
Mobile and highly adaptive, the Ancient North Siberians survived in the region's extreme conditions by hunting woolly mammoths, woolly rhinoceroses, and bison, according to the new research published in the journal Nature.
The study authors estimated that there would have been 40 individuals at the site with a wider population of about 500. There were no evidence found of inbreeding in the DNA, which were quite common at the time when Neanderthal populations were dropping.
"These people were a significant part of human history, they diversified almost at the same time as the ancestors of modern day Asians and Europeans and it's likely that at one point they occupied large regions of the northern hemisphere," study author Eske Willerslev of St John's College, University of Cambridge said in a statement.
Tracing The 'Missing Link' Of Native American Ancestry
Many experts accept that humans traveled from Siberia to Alaska in the Americas via a land bridge across the Bering Strait. In the second paper published in same Nature edition, scientists suggest that some of the humans who made it to the Americas are Asian people mixed with Ancient North Siberians.
These first humans would have been the ancestors of Americas' indigenous people.
Researchers reached this conclusion after analyzing the DNA of a 10,000-year-old male fossil near the Kolyma River in Siberia. Their analysis reveals genetic ancestry that's a mixture of Ancient North Siberian and East Asian, which closely resembles the genetic makeup of Native Americans.
Until now, no human remains have been found outside the United States that are this closely related to Native American populations.
"It is an important piece in the puzzle of understanding the ancestry of Native Americans as you can see the Kolyma signature in the Native Americans and Paleo-Siberians," Willerslev explained. "This individual is the missing link of Native American ancestry."