DNA from ancient population suggests East Asian roots of Native Americans

For the first time, researchers have successfully sequenced the genome of ancient human fossils from the Late Pleistocene in southern China. The data, published in the review Current biologysuggests that the mysterious hominid belonged to an extinct maternal branch of modern humans that may have contributed to the origin of Native Americans.

“The ancient DNA technique is a really powerful tool,” says Bing Su. “This tells us quite definitively that the inhabitants of Red Deer Cave were modern humans instead of an archaic species, like Neanderthals or Denisovans, despite their unusual morphological characteristics,” he says.

The researchers compared the genome of these fossils to that of people around the world. They discovered that the bones belonged to an individual with deep ties to Native American East Asian ancestry. Combined with previous research data, this discovery led the team to propose that some of the inhabitants of southern East Asia had traveled north along the coast of present-day eastern China to across Japan and had reached Siberia tens of thousands of years ago. They then crossed the Bering Strait between the continents of Asia and North America and became the first people to arrive in the New World.

The journey to this discovery began more than three decades ago, when a group of archaeologists in China discovered a large set of bones in the Maludong, or Red Deer Cave, in Yunnan Province, South China. southern China. Carbon dating showed the fossils came from the Late Pleistocene around 14,000 years ago, a time when modern humans had migrated to many parts of the world.

From the cave, researchers recovered a hominid skull cap with features of both modern and archaic humans. For example, the shape of the skull resembled that of Neanderthals and its brain appeared to be smaller than that of modern humans. As a result, some anthropologists had thought that the skull probably belonged to an unknown archaic human species that lived until fairly recently or to a hybrid population of archaic and modern humans.

In 2018, together with Xueping Ji, an archaeologist at the Yunnan Institute of Cultural Relics and Archeology, Su at the Kunming Institute of Zoology, Chinese Academy of Sciences, and his colleagues successfully extracted the ancient DNA of the skull. Genomic sequencing shows that hominin belonged to an extinct maternal line of a group of modern humans whose deceased survivors are now found in East Asia, the Indochinese Peninsula and the islands of Southeast Asia. East.

The discovery also shows that during the Late Pleistocene, hominids living in southern East Asia had a rich genetic and morphological diversity, the degree of which is greater than that of northern East Asia. Is during the same period. This suggests that early humans who first arrived in East Asia had first settled in the south before some of them moved north, Su said.

“This is an important piece of evidence for understanding early human migration,” he says.

Next, the team plans to sequence older human DNA using fossils from southern East Asia, specifically those that predated the Red Deer Cave people.

“These data will not only help us paint a more complete picture of how our ancestors migrated, but will also contain important information about how humans change their physical appearance by adapting to local environments over time, such as variations in skin color in response to changes in sun exposure,” says Su.

– This press release was provided by Cell Press

Nohemi M. Moore