Not really, there are also some other groups. Additionally, the Jomon period people were very diverse and not one singe population. Here are the results of autosomal genome studies:
- Ainu are the direct descendants of the Tohoku and Hokkaido Jomon people.
- Ryukyuans have about 27% southern Jomon ancestry.
- Native Taiwanese were found to have also some Jomon-like ancestry. Some samples from the Amis and Atayal tribes have up to 41% Jomon-like ancestry while most other have generally 0%.
- Modern Japanese (Yamato) have between 0% to 40% Jomon ancestry. A recent study found about 17% Jomon ancestry in modern Japanese.
- Nivkhs and Ulchi are estimated to have up to 25% Hokkaido Jomon ancestry.
The ancient Jōmon people generally had mostly East Asian-related ancestry, not really different from other East Asian lineages. Genetically speaking, the Jōmon were closest to Himalayan populations, such as the Kusunda people, an critically endangered ethno-linguistic group of Nepal, and other East Asian hunter-gatherers. But they also had some geneflow from Upper-Paleolithic groups of Northern Eurasia (ANE), with a North to South cline within the Japanese archipelago.
Kusunda, next to Jōmon samples, such as IK002. (Gakuhari et al. 2020).
We can imagine, that Ainu samples would be positioned in between Jomon/East Asian and ANE clusters. This means, genetically, the Ainu are indeed largely East Asian-related, as many previous studies concluded. Now we also have an explanation why the Ainu frequently have European/Middle Eastern appearance and how these gene alleles arrived into the Ancestral Ainu population!
The Kusunda people, like the proper Jomon people are closer to Basal-East Asians.
Forensic reconstruction of a Jōmon individual:
The Kusunda probably resemble the ancient Jomon the best:
Here a reconstruction of a Hokkaido Jōmon women:
Probably a direct ancestor of living Ainu individuals.
Ainu: