Bayesian phylogenetic analysis supports an agricultural origin of Japonic languages.

In agreement with the scenario, our results indicate that Japonic languages descended from a common ancestor approximately 2182 years ago. Together with archaeological and biological evidence, our results suggest that the first farmers of Japan had a profound impact on the origins of both people and languages. On a broader level, our results are consistent with a theory that agricultural expansion is the principal factor for shaping global linguistic diversity.

Researchers studying the various dialects of Japanese have concluded that all are descended from a founding language taken to the Japanese islands about 2,200 years ago. The finding sheds new light on the origin of the Japanese people, suggesting that their language is descended from that of the rice-growing farmers who arrived in Japan from the Korean Peninsula, and not from the hunter-gatherers who first inhabited the islands some 30,000 years ago.