Researchers at China’s top forensic academy in Beijing say they have found genetic differences between three ethnic groups in East Asia – northern Chinese, Korean and Japanese. These differences are coded in less than 50 variations across the sequence of the human genome, and the scientists said these genetic codes could be used by police to trace someone’s origin as a way to help identify a body. The team from the Ministry of Public Security’s Institute of Forensic Science said this could be done with more than 99 per cent accuracy, even if a tissue sample was badly damaged or degraded. “In recent years, with the frequent social and economic exchanges between China, Japan and South Korea, a large number of people have left their birthplaces to live in other countries and integrate into the local society,” the team led by forensic scientist Li Caixia said in a paper published in the journal Hereditas (Beijing) on Thursday. “The use of genetic markers to infer the ethnic origin of samples plays a key role in forensic practice.” Genetic variations among people from different ethnic groups have generally been found to be negligible, although they may look different. And people from northern China, Japan and the Korean peninsula have a close genetic link. “The genetic relationship between the Han Chinese and Koreans or Japanese is closer than the relationship between the Han and ethnic minorities in China,” Li said in the paper. But after analysing hundreds of samples in their own and other research databases, the scientists found more than 400 possible variations in the genetic codes of people in these three ethnic groups. Eventually those differences were reduced to 49, and with fewer variations to check it was easier and faster to get laboratory results, they said. This unique panel of variations was then tested against real-life genetic sequences collected from northern China, the Korean peninsula and Japan. The team said that with the exception of one error, the results all matched, and their database could be used by forensic experts in the field. 4 genes that shape a Han Chinese face are identified in Shanghai study However, a life scientist with the China National Centre for Bioinformation in Beijing, who was not involved in the study, said the findings should be treated with caution. The scientist, who did not want to be named because of the sensitivity of the issue, said the test database should be expanded to reduce the risk of bias, and that “interpretation and application of these results should be kept strictly within the field of forensic science”. “These tiny differences must not be used for discrimination, nationalism, as biological weapons or for other purposes, to sow more divide or conflict in this region,” he added. Li and her team said their discovery suggested that northern Han Chinese, Japanese and Koreans likely had common ancestors but evolved independently in recent millennia. About 60,000 years ago, modern humans from Africa are believed to have arrived in Southeast Asia, moving north and spreading across China. They may have run into other early human species – including one recently discovered in northeast China with an exceptionally large brain – then likely replaced them all, according to previous studies. More than 3,000 years ago, tribes in the lower Yangtze River area migrated to the Korean peninsula, bringing rice-growing techniques with them. And from South Korea these people migrated to Japan, wiped out the native hunter-gatherer societies on the Japanese islands and established a culture known as Yayoi, according to the paper.