is the generic name of the hunter-gatherer population that lived in the Japanese archipelago during the Jōmon period (). The Jōmon people constituted a coherent population but displayed geographically defined regional subgroups.
Multiple studies on the Jōmon population have analyzed the genetic contribution to modern Japanese. Jōmon samples, represented by a specimen obtained from the Funadomari archaeological site on Rebun Island and two specimens obtained from Honshu, show that mainstream Japanese people have inherited an average of 10-20% of Jōmon ancestry in their genome. The results of a study from 2021 inferred gene flow from the Jōmon population to the modern Japanese across all migration models tested, with genetic contributions ranging from 8.9 to 11.5%. In the same study, the mean Jōmon component of the modern Japanese individual estimated using the admixture analysis was 9.31%.
Population genomic data from various Jōmon period samples show that they diverged from other East Asian people 30,000 to 20,000 years ago. After their migration into the Japanese archipelago in 15,000 to 20,000 BC, they became largely isolated from outside geneflow. A tie between Jomon and Yana was detected but was only marginally significant. Further validation studies using better-quality ancient samples would be necessary. Future studies, particularly additional samples of Paleo-Siberians and ancient Central Asians, would help to elucidate the reason for the potential genetic connection between Yana and Jomon people.
Morphological characteristics
Several studies of numerous Jōmon skeletal remains that were excavated from various locations in the Japanese archipelago allowed researchers to learn more about the Jōmon period population of Japan. The Jōmon people were relatively close to other East Asians, however shared more similarities with Native American samples. Within Japan, regional variance among different Jōmon remains was detected. Historically, the Jōmon people were classified as Mongoloid.
Dental morphology suggests that the Jōmon had Sundadont dental structure which is more common among modern Southeast Asians and Indigenous Taiwanese, and is ancestral to the Sinodont dental structure commonly found among modern Northeast Asians, suggesting that the Jōmon split from the common "Ancestral East Asians" prior to the formation of modern Northeast Asians.
According to the article "Jōmon culture and the peopling of the Japanese archipelago" by Schmidt and Seguchi (2014), the prehistoric Jōmon people descended from various paleolithic populations, which migrated into the Japanese archipelago, using different routes at different times. They concluded: "In this respect, the biological identity of the Jomon is heterogeneous, and it may be indicative of diverse peoples who possibly belonged to a common culture, known as the Jomon. ... These results suggest a level of inter-regional heterogeneity not expected among Jomon groups. This observation is further substantiated by the studies of Kanzawa-Kiriyama et al. (2013) and Adachi et al. (2013). Kanzawa-Kiriyama et al. (2013) analysed craniometrics and extracted aDNA from museum samples that came from the Sanganji shell mound site in Fukushima Prefecture dated to the Final Jomon Period. They tested for regional differences and found the Tokoku Jomon (northern Honshu) were more similar to Hokkaido Jomon than to geographically adjacent Kanto Jomon (central Honshu). Adachi et al. (2013) described the craniometrics and aDNA sequence from a Jomon individual from Nagano (Yugora cave site) dated to the middle of the initial Jomon Period (7920–7795 cal BP). This individual carried ancestry, which is widely distributed among modern East Asians (Nohira et al. 2010; Umetsu et al. 2005) and resembled modern East Asian comparison samples rather than the geographical close Urawa Jomon sample."
A study published in the scientific journal Nature by Jinam et al. in 2015, using genome-wide SNP data comparison, found that the Hokkaido Jōmon samples, ancestral to the Ainu people, differ from Mainland Japanese at several loci, including two genes that are known from a previous study to influence facial features in Europeans (and possibly in other populations).