Population genomic studies have studied into the origin and formation of modern East Asians. Ancestors of East Asians split from other human populations between 70,000 to 50,000 years ago. Possible routes into East Asia by the ancestors of East Asian-related populations include a northern route model from Central Asia, and a southern route model from Southeast Asia. A third route into Northern Siberia was used by a distinct population, represented by the Ancient North Eurasians (古北歐亞人, see below post), which however did not contribute ancestry to modern East Asians. These Ancient North Eurasians however received significant geneflow of an early East Asian-related population, contributing about 22% ancestry towards the ANE, samplified by Mal'ta–Buret' 1 sample.
Fig. (1): Possible route(s) of modern human migrations towards East Asia according to different hypotheses proposed by geneticists (“pincer” or “overlapping” model: both the northern and the southern routes; “southern origin” model: only the southern route), along with representative archaeological sites during the critical period (100,000– 20,000 BP), knowing that the shallow parts of the sea (light gray/blue on the map) were postulated as land area with the lower sea level of last ice age (Sun et al. 2000). References for the archaeological sites: Mal’ta: Vasil’ev (1993); Upper Cave: Chen et al. (1989); Tianyuan Cave: Shang et al. (2007); Huanglong Cave: Wu et al. (2006); Liujiang: Shen et al. (2002); Callao Cave: Mijares et al. (2010).
Figure (2): 人類白細胞抗原基因的計算 Computer simulation of human leukocyte antigen genes supports two main routes of colonization by human populations in East Asia (2015): Topographic map of East Asia showing hypothesized modern human migration routes and suggested barriers. Triangles indicate representative Upper Paleolithic archeological sites with human remains: a. Mal’ta; b. Afontova Gora-2; c. Upper Cave; d. Tianyuan Cave; e. Liujiang; f. Chochen; g. Minatogawa; h. Niah Cave and points indicate modern populations samples for HLA−A, −B, −DRB1 loci: 1. Tuvinians; 2. Oold; 3. Khalkha; 4. Mongolians; 5. Liaoning Han; 6. Shanxi Han; 7. Shandong Han; 8. Xi’an Han; 9. Henan Han; 10. Anhui Han; 11. Hubei Han; 12. Zhejiang Han; 13. Hunan Han; 14. Jiangxi Han; 15. Fujian Han; 16. Maonan; 17. Guangdong Han; 18. Zhuang; 19. Muong.
Modern Northeast Asians consist mostly of the "Northern East Asian" component which has a continuity in Northeast Asia since at least 44,000 BC, and expanded massively with millet cultivation. Modern Southeast Asians consist mostly of the "Southern East Asian" component, which is associated with the spread of rice cultivation. Modern East Asians are positioned in between these two distinct, but closely related lineages.
Figure (3): Proposed migration routes of East-Eurasian paternal haplogroups (C, D, N, O, and Q), during the peopling of East Asia according to the "Northern Route Model". For "Southern Route Model" see earlier post: 早期人類沿海遷徙 Early Human Coastal Migrations.
