The terms Yayoi and Wajin can be used interchangeably, though "Wajin" refers to the people of Wa and "Wajin" is another name for the modern Yamato people. There are several hypotheses about the origin of the Yayoi people:
Another view is that they are from the northern part of the Korean peninsula. This is because the human bones of the :ja:土井ヶ浜遺跡|Doigahama ruins resemble the ancient human bones of the northern part of the Korean peninsula, and pottery is similar to the ":ja:刻目突帯文土器|Engraved band sentence pottery", that is widely used during the Yayoi period and was also discovered in the :ja:シニガイ文化|Sini-Gai culture in the southwestern coastal province of Primorskaya Oblast.
The theory that Yayoi people have multiple origins has also been suggested and is influential.
The historian Ann Kumar presented genetic and linguistic evidence that some of the Yayoi people were of Austronesian origin.
According to several Japanese historians, the Yayoi and their ancestors, the Wajin, originated in the today Yunnan province in southern China. Suwa Haruo considered Wa-zoku to be part of the Baiyue.
The Yayoi were present on large parts of the Korean Peninsula before they were displaced and assimilated by arriving proto-Koreans. Similarly Whitman suggests that the Yayoi are not related to the proto-Koreans but that they were present on the Korean peninsula during the Mumun pottery period. According to him, Japonic arrived in the Korean peninsula around 1500 BCE and was brought to the Japanese archipelago by the Yayoi at around 950 BCE. The language family associated with both Mumun and Yayoi culture is Japonic. Koreanic arrived later from Manchuria to the Korean peninsula at around 300 BCE and coexist with the descendants of the Japonic Mumun cultivators. Both had influence on each other and a later founder effect diminished the internal variety of both language families.
Genetics
It is estimated that Yayoi people mainly belonged to Haplogroup O-M176 , Haplogroup O-M122 and Haplogroup O-M119 , which are typical for East- and Southeast-Asians. :ja:崎谷満|Mitsuru Sakitani suggests that haplogroup O1b2, which is common in today Koreans, Japanese and some Manchu, and O1 are one of the carriers of Yangtze civilization. As the Yangtze civilization declined several tribes crossed westward and northerly, to the Shandong peninsula, the Korean Peninsula and the Japanese archipelago. One study calls haplogroup O1b1 as a major Austroasiatic paternal lineage and the haplogroup O1b2 as a "para-Austroasiatic" paternal lineage. The modern Yamato people are predominantly descendants of the Yayoi people and closely related to other modern East Asians, particularly Koreans and Han Chinese. It is estimated that the majority of Japanese people around Tokyo have about 12% Jōmon ancestry or less. A genome research confirmed that modern Japanese descend mostly from the Yayoi people. Mitochondrial DNA analysis of Jōmon and modern Japanese samples show that there is a discontinuity between the mtDNAs of people from the Jōmon period and people from the Kofun and Heian periods. This finding implies that the genetic conversion of the Japanese people may have occurred during or before the Kofun era, at least at the Shomyoji site.Another genetic study estimated that modern Japanese share more than 90% of their genome with the Yayoi people and less than 10% with the Jomon. A more recent study by Gakihari et al. 2019 estimates that modern Japanese people have on average about 92% Yayoi ancestry and cluster closely with other East Asians but are clearly distinct from the Ainu people. A geneflow estimation by Gakuhari et al. suggests only 3,3% Jōmon ancestry in modern Japanese.
