Jōmon period

In Japanese history, the Jōmon period (Japanese: 縄文時代, Hepburn: Jōmon jidai) is the time between c. 14,000 and 300 BCE, during which Japan was inhabited by the Jōmon people, a diverse hunter-gatherer and early agriculturalist population united by a common culture, which reached a considerable degree of sedentism and cultural complexity. Their ancestors migrated from Northeast Asia, Korean Peninsula, China, and Southeast Asia. Their civilization is divided into six distinct phases. They eventually admixed with the Yayoi people.

The Jōmon period was rich in tools and jewelry made from bone, stone, shell and antler; pottery figurines and vessels; and lacquerware. Jōmon pottery is noted for being decorated by having cords pressed into the wet outside of the pottery. Similar cultures developed in pre-Columbian cultures of the North American Pacific Northwest and especially the Valdivia culture in Ecuador because in these settings cultural complexity developed within a primarily hunting-gathering context with limited use of horticulture.

The approximately 14,000-year Jōmon period is conventionally divided into several phases, progressively shorter: Incipient (13,750–8,500 BCE), Initial (8,500–5,000 BCE), Early (5,000–3,520 BCE), Middle (3,520–2,470 BCE), Late (2,470–1,250 BCE), and Final (1,250–500 BCE). The fact that this entire period is given the same name by archaeologists should not be taken to mean that there was not considerable regional and temporal diversity. The time between the earliest Jōmon pottery and that of the more well-known Middle Jōmon period is about twice as long as the span separating the building of the Great Pyramid of Giza from the 21st century. Dating of the Jōmon sub-phases is based primarily upon ceramic typology, and to a lesser extent radiocarbon dating.

Recent findings have refined the final phase of the Jōmon period to 300 BCE. The Yayoi period started between 500 and 300 BCE according to radio-carbon evidence, while Yayoi styled pottery was found in a Jōmon site in northern Kyushu in 800 BC.

The Japanese archipelago can be divided into 3 regions for which the chronology of the Jōmon period or its subsequent period are applied differently: Honshu and Kyushu, Okinawa and the Ryukyu Isles, and Hokkaido and Northern Tohōku. In Okinawa and the Ryukyu Isles, the Jōmon period does not apply as the Jōmon people were mostly absent from these places. Instead, common chronology for the area uses the Shellmidden Period, or the Sakishima Prehistoric Period specifically for the island. As for Hokkaido and Northern Tohoku, the Jōmon people were replaced not by the Yayoi people like in most of Japan, such as central and southern Honshu, but by the related people of the Zoku-Jomon which ushered in the Zoku-Jōmon Period unique to the North.

The relationship of Jōmon people to the modern Japanese (Yamato people), Ryukyuans, and Ainu is not clear. Morphological studies of dental variation and genetic studies suggest that the Jōmon people were rather diverse, and mitochondrial DNA studies indicate the Jōmon people were closely related to modern-day East Asians. Some of the Jōmon ancestors came from Southeast Asia. The contemporary Japanese people descended from a mixture of the various ancient hunter-gatherer tribes of the Jōmon period and the Yayoi rice-agriculturalists, and these two major ancestral groups came to Japan over different routes at different times.

The modern-day Japanese population carries approximately 30% paternal ancestry from the Jōmon. This is far higher than the maternal Jōmon contribution of around 15%, and autosomal contribution of 10% to the Japanese population. This imbalanced inheritance has been referred to as the "admixture paradox", and is thought to hold clues as to how the admixture between the Jōmon and Yayoi cultures took place. According to Mitsuru Sakiya [ja] the Jōmon people are an admixture of several Paleolithic populations. He suggests that Y-chromosome haplogroups C1a1 and D-M55 are two of the Jōmon lineages. Recent studies suggest that D-M55 became dominant during the late Jōmon period, shortly before the arrival of the Yayoi, suggesting a population boom and bust. The maternal haplogroups M7a, N9b, and G1b have been identified from ancient Jōmon specimens.

The Jōmon period population of Hokkaido consisted of two distinctive populations which later merged to form the proto-Ainu in northern Hokkaido. The Ainu language can be connected to an "Okhotsk component" which spread southwards. They further concluded that the "dual structure theory" regarding the population history of Japan must be revised and that the Jōmon people had more diversity than originally suggested.