Razib Khan offers his conclusion about a new interpretation of southern Korean population genetics and phylogeography: not only do northern Koreans display some features of many neighboring countries, but Japanese samples in certain regions share a great deal of material with southern Koreans.

In the paper itself they’re testing a few historical hypotheses. So I’ll leave it to them for the interpretation:

The gene flow events of the three selected models for SW, MW and SE Korea can be assessed using the genome map. The populations in Model I (SW Korea) are closer to Mongolians than are the other two regions in the genome map (Fig. 2B). Historically, some of the loyal families and their subjects in the Goguryeo Empire moved to this region and formed the BaekJae Empire in BC18-22.

This region also showed connections with populations in Tokyo (JPT), as illustrated in Fig. 4. Certain outliers in Model II (SE Korea) display some similarity to the people of Kobe, a port city near Osaka, indicating that there may have been links between the two regions. In addition, considering that the SE Korea region has some connections with Siberian lineages, with respect to grave patterns and culture, it is possible that the outliers in the GU and Kobe (KB) populations could be of Siberian lineage. On the other hand, the GR and US populations showed average signals in the Korean Peninsula. Historically, the Kaya Empire, with its southern lineages, was formed in the GR region and then the Shilla and Kaya Empires became united around AD532. Very recently, the US region became one of the rapidly developing regions, and people from other provinces moved to this region. This might explain why it shows an average signal in South Korea. Model III (MW Korea): the Middle West area formed a melting pot in the Korean Peninsula because populations moving from South to North, North to South, and from Eastern China, including the SanDung peninsula, to the Middle West in Korea all came together in this region. In the genome map, the signals for MW Korea are also close to those for Peking (CHB) in China. The overall result for the Korea-Japan-China genome map indicates that some signals for Mongolia and Siberia remain in SW Korea and SE Korea, respectively, while MW Korea displays an average signal for South Korea.

The connections between coastal southern Korea and the western islands of Japan are well known. It seems like that the Yayoi people, who probably contributed the preponderance of the ancestry of modern Japanese, arrived in Kyushu approximate ~2,500 years ago. And were originally a group within the Korean peninsula. Over the past 2,000 years Korea has gone through a process of ethnic-linguistic homogenization during the ethnogenesis of the modern Korean nation, but it seems possible that the original group(s) which gave rise to the Yayoi existed in southern Korea to facilitate contact between the islands and the peninsula into the historical era.

Citation: Jung J0, Kang H, Cho YS, Oh JH, & Ryu MH (2010). Gene Flow between the Korean Peninsula and Its Neighboring Countries PLoS ONE : 10.1371/journal.pone.0011855

Filed under: Academia, East Asia, Korea, Population, Science Tagged: china, gene flow, genomics, japan, Korea, phylogeography, population genetics