45,000-Year-Old Man’s Genome is Sequenced, Reveals Clues About Our Origins
A 45,000 leg bone discovered near Ust’-Ishim in Siberia has yielded the oldest genome sequence for Homo sapiens to date and reveals a population that may have once spread throughout northern Asia while offering clues about the journey of modern humans from Africa and encounters with Neanderthals.
Researchers found that a group of the Ust’-Ishim man’s ancestors colonized Asia prior to 45,000 years ago. The man is believed to have lived during a time of expansion of modern humans in Europe.
Researchers compared the man’s genome to 50 different modern populations of humans and found that the individual was more closely related to non-Africans, meaning he was an early representative of the population that exited Africa.
When the man’s genomes were compared to those of modern-day people in East Asia and Europe, it was discovered that he had longer segments of Neanderthal DNA which indicates interbreeding with Neanderthals took place between 50,000 and 60,000 years ago, the BBC reported.
[quote text_size=”small” author=”– Svante Paabo” author_title=”Professor at Max Planck Institute in Leipzig”]
Our analysis shows that modern humans had already interbred with Neanderthals then and we can determine when that first happened much more precisely than we could have before.
All present-day people outside of Africa have some amount of Neanderthal DNA, we know due to a study published in 2010. This genetic material has been broken into smaller chunks over generations. By extrapolating the size of the DNA chunks backward, the researchers were able to calculate when interbreeding with Neanderthals first occurred with greater accuracy.
According to the study’s first author, Qiaomei Fu, the ancient man was equally related to West European hunter-gatherers, North Asian hunter gatherers, East Asians, and the indigenous people of the Andaman Islands, the University Herald reported.
The discoveries from the thigh bone were made possible by a team of scientists led by Svante Paabo. Over the last thirty years, the team has developed tools for extracting DNA fragments from fossils and reading the sequences. In the past, scientists were only able to retrieve small snippets of ancient genes, but they have developed methods to join overlapping fragments together to assemble larger pieces of DNA, the New York Times reported.