who form a cluster in regional comparisons, along with various Tungusic groups. East Asians, including Northeast Asian groups (Mongolic, Turkic, Uralic, Koreanic, Ainuic, Tungusic, Paleosiberian, Amerindian and Japonic) and Southeast Asian ones (Mainland Southeast Asians, Insular Southeast Asians) are closer related to another than other population groups and can trace themselves to a common ancestry from several tens of thousands of years ago. Studies of polymorphisms in the human Y-chromosome have so far produced evidence to suggest that the Korean people have a long history as a distinct, mostly endogamous ethnic group, with successive prehistoric waves of people moving to the peninsula and two major Y-chromosome haplogroups. Koreans show a close genetic relationship with other modern East Asians such as the Yamato Japanese, Southern Tungusic groups and some northern Han Chinese subgroups from Hebei and Manchuria. and with Neolithic specimens recovered from Chertovy Vorota Cave in Primorsky Krai, who themselves are the closest genetic relatives to the Udege and the Hezhen. The reference population for Koreans used in Geno 2.0 Next Generation is 94% Eastern Asia and 5% Southeast Asia & Oceania. According to a genetic distance measurements from a large scale genetic study from 2021 titled 'Genomic insights into the formation of human populations in East Asia', Koreans are genetically closest to Japanese, followed by a larger margin by Northern Han on FST genetic distance measurements. Genealogy Korea Foundation Associate Professor of History, Eugene Y. Park said that many Koreans seem to have a genealogical memory blackout before the twentieth century. According to him the vast majority Koreans do not know their actual genealogical history. Through "inventing tradition" in the seventeenth and eighteenth centuries, families devised a kind of master narrative story that purports to explain a surname-ancestral seat combination's history to the extent where it is next to impossible to look beyond these master narrative stories. He gave an example of what "inventing tradition" was like from his own family's genealogy where a document from 1873 recorded three children in a particular family and a later 1920 document recorded an extra son in that same family. Park said that these master narratives connect the same surname and ancestral seat to a single, common ancestor. This trend became universal in the nineteenth century, but genealogies which were published in the seventeenth century actually admit that they did not know how the different lines of the same surname or ancestral