Researchers rewrote Japanese history after discovering a third, previously unknown group of ancestors of the modern Japanese population who migrated to Japan about 2,000 years ago.
Ancient Japan can be divided into three major eras. During the Jomon period (13,000 BC to 300 BC), a small number of hunter-gatherers who were proficient in pottery lived only on the island. During the overlapping Yayoi period (900 BC to 300 AD), farmers emigrated from East Asia to Japan and developed agriculture. And the Kofun period (300-700 AD) when modern Japan began to take shape.
Previous studies have suggested that the two major genetic origins of the modern Japanese are the first hunter-gatherers who lived in the Jomon period and the peasants who migrated to Japan during the Yayoi period.Well, analysis of DNA The third genetic origin of the Kofun period found in ancient bones was revealed when a previously unknown group of ancestors migrated to Japan, researchers report in a new study. Did.
“I am very excited about the findings of the tripartite. [three-part] Shigeki Nakagoshi, an assistant professor at Trinity College Dublin’s School of Medicine in Ireland, told Live Science: It can’t be seen from modern data alone. “
The Jomon hunter-gatherers appeared in Japan as early as 20,000 years ago and may have maintained a small population of about 1,000 for thousands of years, Nakago said. There is evidence of people who lived in Japan until 38,000 years ago in the Upper Paleolithic. Said in a statementBut little is known about these people.
“The long-standing hypothesis is that they were Jomon ancestors,” Nakagome said. This means that the Upper Paleolithic people may have transitioned to the Jomon people about 16,000 years ago, he added.
Another possible explanation is that the Jomon people were born in East Asia and crossed the Tsushima Strait when they were covered with ice during the last glacial maximum (the latest of the last glacial period, when the ice sheet was widest). is. About 28,000 years ago. , According to the statement.
“But whether these hypotheses are correct remains unclear due to the lack of Paleolithic genomes from Japan,” Nakagome said.
At the beginning of the Yayoi period, there was an influx of people from China Or South Korea with agricultural experience. These people introduced agriculture to Japan, which led to the development of the first social class and the concept of land ownership.
The Yayoi period moved to the Kofun period, when the first political leaders emerged and a single country was formed, which later became modern Japan. However, until now, it was unclear whether the burial mound migration was the result of the third mass migration or the natural continuation of the Yayoi period.
“Cultural transitions may have occurred without genetic changes,” Nakagome said. “Even if the culture looks very different between the two periods, it does not mean that the process involved gene flow.”
Previous studies have suggested a third genetic input from immigrants at the time, but until now it has not been possible to sequence and examine DNA from individuals in burial mounds.
In a new study, Nakagome and his team analyzed the genomes of 12 individuals from all over the country. Nine in the Jomon period and three in the Kofun period were “the first studies to generate whole-genome sequence data from individual tumuli.”
As a result, as others predicted, it became clear that during the Kofun period, a third genetically distinct Japanese ancestor migrated to the country. Nakagome said these ancestors came from East Asia and were probably the Han Chinese of ancient China.
“The Han Chinese are genetically close not only to the ancient Chinese of the Yellow and Xiliao rivers, but also to modern people such as the Tujia, her, and Miao,” Nakagome said. “I think these immigrants came from somewhere in these areas.”
The team’s findings are not surprising to other historians who suspected that this third group of Japanese ancestors existed.
“Archaeological evidence has long suggested three stages of migration, but the last stage has been largely ignored.” Michael Adolphson, a professor of Japanese history at the University of Cambridge who was not involved in the study. He told Live Science. “This new discovery confirms what many of us knew, but now we’re happy to get evidence from the medical field as well.”
The findings also showed that the majority of the genes in the modern Japanese population originated in East Asia over the three major periods of genetic mixing.
According to the team’s analysis, “about 13%, 16%, and 71% of the ancestors of Jomon, Northeast Asia, and East Asia, respectively,” said Mr. Nakagomi. “So East Asian ancestors dominate the modern population.”
However, this study does not reveal whether the migration of East Asians contributed to the transition from Kofun period agriculture to an imperial state.
“The sequenced burial mound individuals were not buried in a keyway-shaped mound. [reserved for high-ranking individuals]”To see if this East Asian ancestor played an important role in the transition, we need to put the top people in order,” Nakagome said.
Nakagome and his team are thrilled to have helped identify new parts of Japanese history and hope that their discoveries will open the door to further discoveries. It’s important to know “where we came from, and the unique history of our own ancestors,” he said.
This study was published online in the journal on September 17th. Science Advances..
Originally published in Live Science.
Ancient bones reveal previously unknown Japanese ancestors
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