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:
Jomon are basically proto-Austronesian
The Kusunda language is the language of a Nepalese tribe with the same name. In their language, they are called Myahq, which means tigers. That is because they live in the forests, mainly hunting. Actually, they don't have a word for green colour because of that.
http://kusunda.linguistics.anu.edu.au/
This language is nearly extinct and is unrelated to other languages. That is, it may be one of the languages spoken in the Himalayas before being supplanted by the Sino-Tibetan languages. There was a number of attempts to connect the Kusunda language to another language family but with no result. When the language became better known, it was understood that is an isolate. The personal pronouns however yield a significant resemblance to the personal pronouns of the Andamanese languages. Its grammar is strikingly different to neighbouring languages.
It is especially important because it could have a relationship with y-dna D. Possibly, the y-dna D-M15 and D-P47 had their own languages which could be related to the Kusunda language, since they show some linguistic similarity to Andamanese languages, whose speakers are also carriers of y-dna D. The Sino-Tibetan language were obviously dispersed by members of y-dna O and that is known because there are Sino-Tibetan speaking tribes who are 100% y-dna O.
There a number of classification schemes for the Sino-Tibetan languages, especially regarding the Tibeto-Burman branch. It is a huge language family and that is self-explanatory, but now we could speak about a certain peculiarity: that there could have been a language family in Tibet unrelated to Sino-Tibetan and connected to the Kusunda and y-dna D-M15 and D-P47, which could bear a unique classification scheme, with its language having special traits which complicate the resolving of the classification of the Sino-Tibetan languages, since there could indeed exist two classification schemes, one powered by superstratum and one by substratum.
In the meantime, the phylogeny of y-dna D has improved. Specifically, we know now that Andamanese belong to D1b-Y34637, forming one cluster with pre-Jomon D1b-M64. Then, both of them form another cluster with Tibetan D1a-Y15407, while all of them together, form their own cluster with the Philippine Negrito D2-L1378. The Andamanese languages connection to D1b-Y34637 and the Ainu languages connection to D1b-M64 is almost certain.
The Mongols also have a special y-dna D subclade, which is D-M533, found with low frequency <3% equally distributed among all Mongols. We know that because it is found in Southern Altai, which had strong Mongolian influence, but not in Northern Altai, which had more Turkic influence. Also, it is found in Eastern Yugurs, who are Mongolic-speaking with a frequency of 12%, but it is absent from Western Yugurs, who are Turkic-speaking. There are also some cases in Eastern Europe.
Some persons were luckily discovered who knew the language but some of them passed away. Till late, they helped Nepalese linguists with the recording of Kusunda.
This is the last family who is known to possess knowledge of the language. Who knows, maybe there are still some more speakers of Kusunda dwelling in the forests of Himalayans.