Jōmon period
In Japanese history, the Jōmon period is the time between, 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 Japonic-speaking 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.
Chronology
The approximately 14,000-year Jōmon period is conventionally divided into several phases, progressively shorter: Incipient, Initial, Early, Middle, Late, and Final. 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.
Origin and ethnogenesis
The relationship of Jōmon people to the modern Japanese, 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 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.
File:140913 Sannai-Maruyama site Aomori Japan01bs6bs6.jpg|thumb|255x255px|Reconstruction of the Sannai-Maruyama Site in the Aomori Prefecture. It shares cultural similarities with settlements of Northeast Asia and the Korean Peninsula, as well as with later Japanese culture.|alt=Reconstruction of prehistoric site
The prehistoric Jōmon people descended from diverse paleolithic populations with multiple migrations into Jōmon-period Japan. They concluded: "In this respect, the biological identity of the Jōmon is heterogeneous, and it may be indicative of diverse peoples who possibly belonged to a common culture, known as the Jōmon". The modern Japanese people descended from three primary groups: hunter-gatherers who arrived in Japan 15,000 BCE in the Jōmon era, farmers starting around 900 BCEwhich introduced small-scale farming to the Jōmon and eventually leading to the Yayoi period, and 300-700 CE during the Kofun period.
A 2015 study found specific gene alleles, related to facial structure and features among some Ainu individuals, which largely descended from local Hokkaido Jōmon groups. These alleles are typically associated with Europeans but absent from other East Asians, which suggests geneflow from a currently unidentified source population into the Jōmon period population of Hokkaido. Although these specific alleles can explain the unusual physical appearance of certain Ainu individuals, compared to other Northeast Asians, the exact origin of these alleles remains unknown. Matsumura et. al, however, states that these phenotypes were shared by prehistoric South Chinese and Southeast Asian peoples. Other studies suggest relative phenotypic homogenetiy among different Jōmon specimens in Japan.
Full genome analyses in 2020 and 2021 revealed further information regarding the origin of the Jōmon peoples. The genetic results suggest early admixture between different groups in Japan already during the Paleolithic, followed by constant geneflow from coastal East Asian groups, resulting in a heterogeneous population which then homogenized until the arrival of the Yayoi people. Geneflow from Northeast Asia during the Jōmon period is associated with the C1a1 and C2 lineages, geneflow from the Tibetan Plateau and Southern China is associated with the D1a2a and D1a1 lineages. Geneflow from ancient Siberia into the northern Jōmon people of Hokkaido was also detected, with later geneflow from Hokkaido into parts of northern Honshu. The lineages K and F are suggested to have been presented during the early Jōmon period but got replaced by C and D. The analysis of a Jōmon sample and an ancient sample from the Tibetan Plateau found only partially shared ancestry, pointing towards a "positive genetic bottleneck" regarding the spread of haplogroup D from ancient "East Asian Highlanders". The genetic evidence suggests that an East Asian source population, near the Himalayan mountain range, contributed ancestry to the Jōmon period population of Japan, and less to ancient Southeast Asians. This points to an inland migration through southern or central China towards Japan during the Paleolithic. Another ancestry component seem to have arrived from Siberia into Hokkaido. Archeological and biological evidence link the southern Jōmon culture of Kyushu, Shikoku and parts of Honshu to cultures of southern China and Northeast India. A common culture, known as the "broadleafed evergreen forest culture", ranged from southwestern Japan through southern China towards Northeast India and southern Tibet, and was characterized by the cultivation of Azuki beans.
Some linguists suggest that the Japonic languages were already present within the Japanese archipelago and coastal Korea, before the Yayoi period, and can be linked to one of the Jōmon populations of southwestern Japan, rather than the later Yayoi or Kofun period rice-agriculturalists. Japonic-speakers then expanded during the Yayoi period, assimilating the newcomers, adopting rice-agriculture, and fusing mainland Asian technologies with local traditions.
Linguistics research based on specific Austronesian vocabulary loaned into the core vocabulary of Japanese indicates Austronesian peoples were in the Japanese archipelago during the Jōmon period. These Austronesian-speakers arrived in Japan during the Jōmon period and prior to the arrival of Yayoi period migrants, associated with the spread of Japonic languages. These Austronesian-speakers were subsequently assimilated into the Japanese ethnicity. Evidence for non-Ainuic, non-Austronesian, and non-Korean loanwords are found among Insular Japonic languages, and probably derived from unknown and extinct Jōmon languages.
Other studies suggest that the Jōmon form a clade with Ancient Northern and Southern East Asians. They diverged from Ancient East Asians around the same time as the Longlin specimen from Guangxi, China although other studies show an earlier divergence date for the latter. The Jōmon likewise diverged from Ancient East Asians much later than the basal Xingyi_EN lineage. According to Wang et al., the ancestors of Ancient East Asians were a mixture of Tianyuan-related and Xingyi_EN-related lineages. The Jōmon also exhibit a high degree of genetic homogeneity,which is attributed to "strong bottleneck and small effective population size". Additional admixture between the Jōmon and coastal East Asians is also present although there is no evidence of Austronesian-related input, for instance, in the Jōmon, including Ryukyuan Jōmon.