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. The result provides support for a wider picture, controversial among linguists, that the distribution of many language families today reflects the spread of agriculture in the distant past when farming populations, carrying their languages with them, grew in numbers and expanded at the expense of hunter-gatherers. Under this theory, the Indo-European family of languages, which includes English, was spread by the first farmers who expanded into Europe from the Middle East some 8,000 years ago, largely replacing the existing population of hunter-gatherers.
In the case of Japan, archaeologists have found evidence for two waves of migrants, a hunter-gatherer people who created the Jomon culture and wet rice farmers who left remains known as the Yayoi culture. The Jomon people arrived in Japan before the end of the last ice age, via land bridges that joined Japan to Asia’s mainland. They fended off invaders until about 2,400 years ago when the wet rice agriculture developed in southern China was adapted to Korea’s colder climate.
Several languages seem to have been spoken on the Korean Peninsula at this time, and that of the Yayoi people is unknown. The work of two researchers at the University of Tokyo, Sean Lee and Toshikazu Hasegawa, now suggests that the origin of Japonic — the language family that includes Japanese and Ryukyuan, spoken in the Ryukyu island chain south of Japan — coincides with the arrival of the Yayoi. The finding, if confirmed, indicates that the Yayoi people took Japonic to Japan, but leaves unresolved the question of where in Asia the Yayoi culture or Japonic language originated before arriving in the Korean Peninsula.