The origins of China’s biggest ethnic group can be traced back to three river valleys, deposing the Yellow River as the sole cradle of Chinese civilisation, according to a new study.
The river has long been hailed as the mother river of Han Chinese, who make up nearly 92 per cent of the country’s population today.
But research published in the online journal Molecular Biology and Evolution on Wednesday said the lower reaches of the Yangtze and Pearl rivers – as well as the Yellow River – gave rise to genetically separate groups about 10,000 years ago. Those ancestors then mingled to become the largest ethnic group in the world today, it said.
“The history of Han Chinese is more sophisticated than thought,” said Professor Kong Qingdong, a researcher with the Kunming Institute of Zoology at the Chinese Academy of Sciences and lead scientist in the study. “Many details need investigation.”
After analysing DNA samples from more than 20,000 unrelated Han Chinese, examining their dialects and family geography and comparing those to archaeological DNA records, scientists concluded that the Yangtze and Pearl rivers had equal claim to Han origins as the Yellow River.
The rivers may have changed course significantly over time, which means that the exact locations of populations millennia ago are unclear.
Progenitors from the three river valleys evolved independently, the Kunming team said, and distinctions found in the mitochondrial DNA – that is, the mother’s line – of the study volunteers added weight to their assertion.
About 0.07 per cent of the DNA examined in the Han Chinese study differed according to river valley origin. By comparison, the difference was much lower – 0.02 per cent – when the study volunteer data was assessed by dialect, the researchers said.
Earlier studies of genetic markers and microsatellite data that mapped the prevalence of DNA revealed that Han Chinese can be generally divided into two groups: North and South. The latest study found that the genetic variation between North and South Han Chinese is 0.03 per cent, considerably less significant than the distinction by rivers.
Dr Li Yuchun, lead author of the paper, said the findings helped trace the history of Han to the dawn of civilisation, the emergence of agriculture and the sustainable growth of population.
The earliest migrants from Africa to China arrived in what is now the southwest between 60,000 and 100,000 years ago, studies said. The genes of this group of hunter-gatherers were largely unchanged for tens of thousands of years.
About 10,000 years ago, agricultural practices began to emerge in the valleys of the three rivers. Archaeologists found evidence of millet cultivation around the Yellow River, rice in the Yangtze, and roots and tubers in the Pearl.
“Increasing food led to a population boom in these areas. We can see it in the separate path of gene evolution,” Li said.
The research also found that women were able to preserve their genetic story better than men as they stayed at home to tend the fields, while men went to explore, trade or wage war.
“Females are resilient to invasion,” she said.
The research team planned to examine the Y-chromosome, which is passed from father to son, to study the expansion of the Han civilisation, Li said.
“It will be interesting to hear the story from a male perspective,” she said.
As the Han empires expanded, many ancient ethnic groups such as Huns, Siberians, Khitan in northern China and the Thai-Khadai speaking peoples in the south vanished from history.
Some researchers think these minorities became extinct, but others believe they were absorbed into the Han Chinese population.
More from South China Morning Post:
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This article Beyond the Yellow River: DNA tells new story of the origins of Han Chinese first appeared on South China Morning Post