Evrim Yazgin
Cosmos science journalist
Genomes from Yunnan in southwestern China, dating from 7,100 to 1,400 years ago, have been sequenced for the first time, revealing new insights about the links between different cultural groups from Tibet to South and Southeast Asia.
The findings, published in the journal Science, come from the genomes of 127 ancient humans.
Yunnan province today borders Tibet in the northwest, Myanmar in the west, and Laos and Vietnam in the south.
The genome of the 7,100-year-old individual threw up one of the biggest surprises. It was as genetically different to most present-day people living in East Asia as the genome of a 40,000-year-old individual found in Beijing, suggesting a previously unknown Asian ancestry.
The authors of the new study refer to the newly observed Asian culture as Xingyi ancestry.
The Xingyi individual shared traits with today’s indigenous populations of the Qinghai-Tibet Plateau, distinct from other populations.
An early Asian population separated at least 40,000 years ago, persisting in what is today southwestern China, before mingling with other human groups which were migrating westward toward Tibet, according to the study’s findings.
An 11,000-year-old individual’s genome which was sampled in an earlier study also shows Xingyi ancestry, according to the new research. This individual was found in the Guangxi province which borders Yunnan to the east. Modern Guangxi people have lost any evidence of Xingyi ancestry.
Further Yunnan genomes sampled from 5,100 to 1,400 years ago show this population split from northern and southern groups in East Asia about 19,000 years ago.
As well as being linked to other East Asian populations, the ancient samples from Yunnan also showed close genetic relationship to people who speak languages in the Austroasiatic group.
Austroasiatic is a family of languages spoken in the mainland of Southeast and South Asia.
More than 100 million people speak more than 150 Austroasiatic languages and dialects today in regions like Vietnam, Cambodia, Thailand, Laos, Myanmar, India, Bangladesh, Nepal, and southern China. Major languages include Vietnamese, Khmer, Mon and Munda languages.
Previously, scientists thought the spread of Austroasiatic speakers was linked to the growth of agriculture, but the presence of Austroasiatic-related people in central Yunnan, revealed in the new study, predates farming. It is the oldest evidence of Austroasiatic populations and could help explain the origin of this group.
The study highlights the genetic divergence in East Asia which is among the most diverse human populations in the world.
