First is the question of where the MRCA of N-M231 and O-M175 has lived. This is a question of purely theoretical (via what route have anatomically modern humans spread across the globe? type) interest IMHO, and does not bear much relevance upon the genomic affinities among modern populations who carry these Y-DNA lineages vis-a-vis one another or vis-a-vis modern populations who do not contain any N-M231 or O-M175 lineages because the branch length between the K2 node and the NO node is short (approx. 4,000 years), and the MRCA of N and O should have lived only about 3,500 years after the Ust-Ishim specimen or the MRCA of that Telugu "X" person's lineage and NO-M214. I would say this is one of the shortest branch lengths between any pair of well-known nodes of the phylogenetic tree, and it illustrates how ephemeral the connection between haplogroups N and O actually is. I think it would almost be better for the general understanding if the M214 SNP had not been discovered so early and people only knew of haplogroups N and O as individual subclades of K-M9 (or even F-M89). The M214 SNP ranks up there with the likes of F929 (HIJK) and M523 (IJK) among the most delusive SNPs. This is qualitatively different from the likes of QR-M45, which indicates a quite significant exclusive relationship between haplogroups Q and R (approx. three times as significant as the relationship between N and O, or roughly 12,000 years of shared ancestry subsequent to the MRCA of K2a and K2b). In fact, the branch length between GHIJK and NO is only about 8,000 years (or roughly somewhere between 2,000 and 14,000 years considering the 95% confidence intervals), so the closeness of the relationship between N and O vis-a-vis haplogroup G is probably less than the closeness of the relationship between Q and R vis-a-vis haplogroup N or haplogroup O.
If two haplogroups related to the degree to which Q and R are related to each other may have expanded mainly among the ancestors of populations as different as modern Native Americans and modern Europeans, then N and O could have expanded among the ancestors of populations even more different than modern Native Americans and modern Europeans.
This leads us to the second issue: from where and from what sort of population has N-M231 spread since its emergence from a bottleneck approximately 22,000 to 23,500 YBP? If modern representatives of haplogroup N were mostly found only in one sort of population (e.g. Uralics), then it would be relatively uncontroversial to infer that haplogroup N has spread from a proto-Uralic sort of people living in whatever region proto-Uralic-type people are supposed to have originated. However, Haplogroup N is in fact much more common among modern East Asians than haplogroup Q is common among modern Europeans. So, although it is theoretically plausible that haplogroup N and haplogroup O might have developed and expanded from populations more different from each other than modern Europeans are different from modern Native Americans, the actual distribution shows both haplogroups, N and O, to be quite common among modern East Asians. What does this mean? Are modern East Asians hybrids between some sort of Uralic-type population and a different East Asian-type population? That might be an unpopular idea, but perhaps it should be considered.
If the presence of both N and O among modern East Asians were ascribable solely to long-term (on the order of 40,000 years!) maintenance of a large effective population size of a single East Asian meta-population, then I think we should not expect to observe such a great difference between the MRCA of O-M175 on the one hand (approx. 34,000 to 38,000 YBP) and the MRCA of N-M231 on the other (approx. 22,000 to 23,500 YBP). Perhaps there were at least two distinct populations in Palaeolithic East Asia, with the haplogroup O population being more successful than the haplogroup N population. Alternatively, perhaps only haplogroup O (or only haplogroup N) is really native to East Asia, and the other haplogroup has spread over the region relatively recently (probably from Siberia if haplogroup N is invasive or from Southeast Asia if haplogroup O is invasive).
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Originally Posted by alfieb
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