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.