Chinese researchers reported on Friday that an analysis of sequenced ancient genomes revealed a major episode of admixture of ancient humans in East Asia, suggesting that population movement played a profound role in the early genetic history of East Asians.

Researchers from the Institute of Vertebrate Paleontology and Paleoanthropology of the Chinese Academy of Sciences reported in the latest issue of the journal Science online that they retrieved ancient DNA from 25 ancient human remains dating back 9,500 to 4,200 years and one dating back 300 years from sites across China.

They found that Early Neolithic East Asians were more genetically differentiated from each other than present-day East Asians are.

In early Neolithic East Asia since 9,500 years ago, a northern ancestry existed along the Yellow River and up into the eastern steppes of Siberia, while a southern ancestry existed along the coast of the southern Chinese mainland and islands in the Taiwan Strait since 8,400 years ago.

But present-day Chinese from both the north and south share a closer genetic relationship to northern Neolithic East Asians along the Yellow River.

Further analyses showed northern ancestry played a larger role in the genetic admixture. Population movement, particularly from the north along the Yellow River southward, was a prominent part of East Asian prehistory after the Neolithic.

They added that unlike in Europe, influences from Central Asia had no role in the formation of East Asian ancestry, with mixing largely occurring regionally between northern and southern populations in East Asia.

Meanwhile, southern ancestry is found to have extensive influence on other regions. Present-day Austronesian speakers, who live across a wide swath of islands in Southeast Asia and the Southwest Pacific, show a remarkably close genetic relationship to Neolithic populations from the southern coast of China.

The researchers noted this provides evidence that Austronesian speakers today originated from a population derived from southern China at least 8,400 years ago.

Austronesian refers to a family of languages spoken in the area extending from Madagascar eastward through the Malay Peninsula and Archipelago to Hawaii and Easter Island and including almost all the native languages of the Pacific islands.

The researchers said their study highlights the profound impact that population movement and mixture had on human history.