40,000-Year-Old Chinese Man's Genome Points To Diverse Genetic Landscape Between Europeans, Asians

Advanced genome analysis of a man that died in the Tianyuan Cave near Beijing 40,000 years ago has shed more light on the early Asian population.

According to a study published in Current Biology, a team of researchers from the Molecular Paleontology Lab at the Chinese Academy of Sciences Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) led by Professor FU Qiaomei use advanced ancient DNA sequencing techniques to retrieve DNA from Tianyuan man that spans the human genome.

Archaeological findings from Europe and Siberia have been sequenced for genome analysis but research on samples from Asia was not so widely done.

According to a report published in EurekAlert, “this new study on the Tianyuan man marks the earliest ancient DNA from East Asia, and the first ancient genome-wide data from China.”

The Tianyuan man was studied in 2013 by the same lab, said the report. Back then, “they found that he showed a closer relationship to present-day Asians than present-day Europeans, suggesting present-day Asian history in the region extends as far back as 40,000 years ago.”

But new molecular analysis tools since then enabled the team to do a much more comprehensive study. Professor FU and the team, with experts at the Max Planck Institute of Evolutionary Anthropology and UC Berkeley, sequenced and analyzed parts of the genome, particularly at positions also sequenced in other ancient humans.

While there was nothing surprising about the finding of the study that the closest relationship the Tianyuan man shared was with present-day Asians, parallels between his genome and a 35,000-year-old individual from Belgium named GoyetQ116-1 revealed some unexpected shared genetic similarity.

Though the researchers ruled out direct interactions between the two populations represented by the Tianyuan and GoyetQ116-1 individuals, they suggested that they derived some of their ancestry from the same sub-population prior to the European-Asian separation.

The genetic relationship observed between these two ancient individuals is direct evidence that European and Asian populations have a complex history, the study concluded.

The research also confirmed a 2015 study that compared present-day populations in Asia, the Pacific and the Americas. It proposed that some Native American populations from South America had an unusual connection to some populations south of mainland Asia, most notably the Melanesian Papuan and the Andamanese Onge.

The 2015 study proposed the population that crossed into the Americas around 20,000 years was not a single unit, but one or more related but distinct populations, one of which had additional ties to an Asian population that also contributed to the present-day Papuan and Onge.

The Tianyuan man possesses genetic similarities to the same South Americans, in a pattern similar to that found for the Papuan and Onge, the new study found, conforming that the multiple ancestries represented in Native Americans were all from populations in mainland Asia.

What makes this finding intriguing is that migration to the Americas occurred approximately 20,000 years ago, but the Tianyuan individual hails from a time double that period.

Thus, the diversity represented in the Americas must have persisted in mainland Asia in two or more distinct populations since 40,000 years ago, the study said.

The deeper sequencing of the Tianyuan man's genome reveals a complicated separation for ancient Europeans and Asians and hints at a diverse genetic landscape for humans in East Asia.

Though he derives from a population that is related to present-day East Asians, he is not directly ancestral to these populations, suggesting that various genetically distinct populations were present in Asia from 40,000 years ago until the present.