Page "Jōmon period" Paragraph 12

By the end of the Incipient Jōmon phase, around 8, 000 BC, this semi-sedentary culture led to important population increases, so that the Initial Jōmon exhibit some of the highest densities known for foraging populations.

Genetic mapping studies by Cavalli-Sforza have shown a pattern of genetic expansion from the area of the Sea of Japan towards the rest of eastern Asia.

This appears as the third principal component of genetic variation in Eurasia ( after the " Great expansion " from the African continent, and a second expansion from the area of Northern Siberia ), which suggests geographical expansion during the early Jōmon period.

These studies also suggest that the Jōmon demographic expansion may have reached America along a path following the Pacific coast.