1. Accueil
  2. Pages cachées
  3. When and where the three major populations of Africa, Europe and East Asians diverged and suggests why the Ainu look like Europeans

When and where the three major populations of Africa, Europe and East Asians diverged and suggests why the Ainu look like Europeans

Part.2

What are the implications for Japanese settlement and migrational history theory:

To recap, this is what we can glean from this study with respect to the populating of Japan.

- East Asians diverged from their African ancestors ∼55,000 years ago –>

Earliest East Asian grouping

YAP-A   which is made up of C, D and YAP+ hgs. This group comprises mainly of Khalkh Mongolians and predominantly Japanese (all arching Japanese grouping, note: ancestral lineages Jomon, Ainu showed highest frequencies of YAP+, but a significant component of the lineages of the modern Japanese population today still carry a strong signal of the ancient YAP+ gene. YAP+ is an ancient Out-of-Africa marker – borne only by group), Koreans and Europeans in somewhat more miniscule numbers. (This is presumably is the oldest Out-of-Africa grouping, because it includes YAP+ genes.)

The study proposes that Ainu arose out of hybrid individuals were born before the divergence of Europeans from East Asians ∼41,000 years ago, and some of whom looked more like the Europeans while possessing a generally East Asian genotype may have diverged. The ancestor of the Ainu originated in northern Eurasia and took a route through Siberia and north China before settling in northern regions of Japan and nearby places.

The study also proposes that the people in Okinawa islands being closest to the Ainu people in the East Asians (Jinam et al. 2012),were likely descendants from of mixing of East Asian and European lineages.

According to the study, the Y-STR tree (focusing on male lineages comprising Japanese, Korean, Mongolian (Khalkh), American, and European people only), revealed that the male ancestral lineage contained two clades (Yap-A and Yap-B). While Yap-A clade includes the East Asian individuals only, Yap-B clade contains the East Asian and European individuals together.

- East Asian and European groups diverge at around 41,000 ya

in the East Asian-only group – Yap-B1 in figure 1 belonged to either haplogroup C or D [Other studies have proposed that C and D lineages are the earliest or among the earliest groups to settle East Asia.  Hg C is thought to have come from a southerly possibly coastal origin, while D from a either a southerly or southwesterly direction]  However, since Yap-B1 includes mainly Japanese and Korean males, in which 91% individuals share haplotype O2b, the Korean and Japanese males are definitely closest to one another within East Asian humans (a high frequency of the O2b haplotype also found in Manchu (Northern China) and Korean-Chinese samples).

- The branching of NO – and the branching of Y-DNA O into subclades on the continent is a highly complex picture and the roots of the tree only beginning to be understood.  According to the study the majority of Yap- B2 belonged to haplogroup O.  The European males never formed an independent clade. Instead, they formed separate clades within Yap-B.

A few points I wish to make here:

Given that the study’s groupings of Yap A and YAP B1 and B2 groups involve the haplogroups C, D and O, it is surprising that the paper does not cite or try to reconcile the results of important studies that have proposed the origins and migrational paths for these groups.  For example,

Abstract: “…our detailed analysis of hg N suggests that its high frequency in east Europe is due to its more recent expansion westward on a counter-clock northern route from inner Asia/southern Siberia, approximately 12–14 ky ago. The widespread presence of hg N in Siberia, together with its absence in Native Americans, implies its spread happened after the founder event for the Americas. The most frequent subclade N3, arose probably in the region of present day China, and subsequently experienced serial bottlenecks in Siberia and secondary expansions in eastern Europe. Another branch, N2, forms two distinctive subclusters of STR haplotypes, Asian (N2-A) and European (N2-E), the latter now mostly distributed in Finno-Ugric and related populations. These phylogeographic patterns provide evidence consistent with male-mediated counter-clockwise late Pleistocene–Holocene migratory trajectories toward Northwestern Europefrom an ancestral East Asian source of Paleolithic heritage.”

Excerpts from the body of the paper:

” … the spatial distributions for ancestral paragroup NO-M214*, paragroup N-M231* and the prevalent hg O-M175 (Figure 2a, c, d) are generally congruent and highlight Southeast Asia as the most parsimonious source region of these clades. The spread pattern of paragroup NO*approximates the same regions of Southeast Asia as paragroup N*, although being present at an even lower frequency compared with N*18, 19 (data from Kayser et al19 updated in present study). More notable, however, is the fact that the spatial dynamics of the whole N and O haplogroups greatly differ from each other. The split between N* and O is dated to 34.6plusminus4.7 thousand years (ky). The age of STR variation of hg O in Southeast Asia probably exceeds 26 ky,10 and its numerous subclades currently predominate in southern and southeastern Asia extending into northern China, Manchuria and some Siberian populations,7, 9, 11,20,21 as well as westward to the eastern sector of the Indian subcontinent10 and eastward to Oceania.

The phylogeography of the NO* and N* lineages (Figure 2a, d) and the presence of N* chromosomes in southern East Asia (South China and Cambodia, see Supplementary Table 1) suggests that this region could be the source of the initial spread of hg N. In this scenario, the Altay/Sayan/southern Siberia region might have been a place of transition of hg N westward as all major subclades of hg N are still to be found there. …

In summary, Y chromosome haplogroup N presents a case of gene flow to eastern Europe that has its likely ultimate source in east Asia.”

See also the other paper by SHi H, et al, “Genetic Evidence of an East Asian Origin and Paleolithic Northward Migration of Y-chromosome Haplogroup N” and also  Austro-Asiatic Tribes of Northeast India Provide Hitherto Missing Genetic Link between South and Southeast Asia Mohan Reddy et al., PLoS ONE. 2007; 2(11): e1141. 2007 (alternative theory for the origin of O-M95 in the Austro-Asiatic tribes of N-E India.

***

The 2014 paper in ignoring the aforementioned research papers leaves hanging other fundamental questions: Before East Asia, what was the route taken out of Africa of all these founding haplogroups – a southern one or northern one, single migration route or multiple (See Single, Rapid Coastal Settlement of Asia Revealed by Analysis of Complete Mitochondrial Genomes, Vincent Macaulay et al.,  Science 13 May 2005: Vol. 308 no. 5724 pp. 1034-1036DOI:10.1126/science.1109792; ; Extended Y chromosome investigation suggests postglacial migrations of modern humans into East Asia via the northern route. Zhong H, et al. Mol Biol Evol. 2011 Jan;28(1):717-27.

Finally, the Japanese samples are classified broadly as Japanese samples (but Ainu and Okinawan and ancient Jomon DNA, are usually differentiated from modern Honshu Japanese samples, here it is all lumped here into one great grouping). Would the study’s results have showed a vastly different picture had they tested against specific samples of Ainu, ancient Jomon (different locations in Japan), as well as against against different continental populations of Altai-Buryat Mongols, Tibetans, Tungusic-Amur or Nikhs peoples, Yakuts, Evenkhs, Kazakhs???