Where the Yoshinogari people came from is not a settled question today.
When the site was first discovered, some archaeologists felt that the moated settlement resembled the circular castle wall settlements of China.
Other experts were certain that Yoshinogari had its origins in the Mumun culture, and that the settlers were Mumun farmers from Korea. These experts believe Yoshinogari had connections with the Mumun period settlements of Korea. Yoshinogari shared the same features such as Igeum-dong site’s large raised floor buildings; the multiple-ditch and palisade settlements of Daepyeong and Geomdan-ni (that appeared 850-550 BC during the Middle Mumun Pottery period), and the large cemeteries of Yulha-ri’s (that appeared 550 – 300 B.C during the Late Mumun period).
Because the Mumun period settlements went into decline just as the Yayoi period settlements in Kyushu began, some archaeologists believe that Mumun farmers migrated to Japan and began the Yayoi culture.
Others thought of the Yayoi people as indigenous Japanese inhabitants who had strong economic, trade and cultural associations with the Mumun peoples.
However, DNA testing of the rice and silk excavated in the deepest layer of the soil unexpectedly found a perfect match in the DNA of the ones found in the archaeological sites that were dug out along the Yangtze River in southern China. The rice of the Chinese and Yoshinogari sites were all of the tropical Japonica type. By contrast, none of the DNA tests matched the ones found in northern China or the Korean Peninsula.
It was concluded from the DNA tests, that people from southern China 江南、the Long River Civilization had brought with them the rice and silk to Japan.
Supporting this conclusion, is the theory that although seagoing craft and technology were primitive at the time, the sea currents possibly helped voyages from Jiangsu and Zhejiang across the East China Sea to Kyushu, making a reasonable sea route between ancient Japan. It is thought that these sea voyages may have begun in the Hemudu periods bringing to Japan, the Hemudu neolithic culture
and other cultural factors popular in the lower Yangtze basin such as the making of jiatanheitao
(a kind of pottery containing fibers), woodware and the habit of tooth extraction. This allows us to conclude jue
and lacquerware were not the only elements exported, and that ties of Hemudu culture
and later cultural periods continued. Thus, it is thought that jade jue
and lacquerware arrived in Japan as early as 4000-5000 BC; rice cultivation was taken to Korea and Japan ca. 1000 BC; and balustrade construction was introduced to Japan before Han Dynasty.
These results are similar to tests of DNA of rice samples from the Karako-Kagi site which also matched those from the sites of the Long River area, southern China.
Testing of DNA samples from Yoshinogari and Karako-kagi sites, however, contrast with those of DNA sequences found in ancient human remains excavated from the Tottori prefecture, the results showed that the Yayoi settlers in the site belonged to the same group as those of present-day South Koreans and Japanese living on the island of Honshu.
However, DNA tests of Yoshinogari artefacts from the later period however showed that these settlers of southern Chinese origin also interacted with people from the Korean peninsula.
It appears that a picture of mixed origins is emerging in the search for origins of the Yayoi people.
Excavations of Large-scale Megalithic Burials at Yulha-ri, Gimhae-si, Gyeongsang Nam-do by Martin T. Bale, University of Toronto, Canada
Origin of rice paddy cultivation at the Hemudu site by Shao Jinhua, Hemudu Site Museum, Zhejiang Province, China
The Hemudu site
Ancient culture of the Lower Yangtze River and Ancient Japan by An, Jimin
See also Yayoi linked Yangtze area: DNA tests reveal similarities to early wet-rice farmers