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"Basal Eurasian" may be ~80 ky old
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[QUOTE]Originally posted by the lioness,: [QB] [QUOTE]Originally posted by Oshun: but M and N are being dated at 55k. Yet according to this, Basal [/QUOTE] [QUOTE] Pleistocene Mitochondrial Genomes Suggest a Single Major Dispersal of Non-Africans and a Late Glacial Population Turnover in Europe Posth 2016 Dating the most recent common ancestor of each of the modern non-African mtDNA clades reveals their single, late, and rapid dispersal less than 55,000 years ago. Genetic studies of human mitochondrial DNA (mtDNA) show that all present-day non-Africans belong to two basal mtDNA hap- logroups (hgs), M and N [10]. The time to the most recent common ancestor (TMRCA) of each of these two clades has been estimated independently at around 50,000 years ago (50 ka) (95% confidence interval [CI], 53–46 ka) Surprisingly, three hunt- er-gatherers from Belgium and France dating to between 35 and 28 ka carried mtDNA hg M, today found predominantly in Asia, Australasia, and the Americas, although it is almost absent in extant populations with European ancestry Excluding a $40,000-year-old Romanian individual known not to have contributed notably to the modern European gene pool [28], our BEAST analyses give a TMRCA for clades M and N from 44 to 55 ka, respectively. Our estimated dates, together with the oldest accepted archeological evidence for the pres- ence of early modern humans in Australia and Europe (both dated to at least 45 ka [13, 29]), are consistent with a model of a single, late, and therefore rapid dispersal of a source popula- tion containing both M and N hgs, which contributed all the mito- chondrial diversity of present-day non-Africans (cf. [7]). Human individuals whose ancestries trace back to potential earlier ex- pansion(s) outside Africa [30, 31] are thus unlikely to have left any surviving mtDNA descendants. The reconstructed phylogeny (Figure 2) with both basal N and M lineages in Late Pleistocene Europe possibly mirrors the inferred back migration into Africa, which has been suggested by the existence of hgs U6 and M1 in modern-day North Africans [33]. Therefore, the major modern human dispersal described here after 55 ka might have affected not only non-Africans, but also African populations to some extent. Hg assignment of the authenticated mtDNAs confirmed that the vast majority of Late Pleistocene and Early Holocene individ- uals belonged to the U lineage, which is a subgroup of the N clade [20] (Figures 2 and S1). We also found a basal U lineage that had no derived position leading to known sub-hgs in a 33,000-year-old Romanian individual. Surprisingly, three hunt- er-gatherers from Belgium and France dating to between 35 and 28 ka carried mtDNA hg M, today found predominantly in Asia, Australasia, and the Americas, although it is almost absent in extant populations with European ancestry [/QUOTE] [QUOTE] Informally, the topology and branch lengths of genealogies are affected by a demographic history in two ways: [b]1. Two lineages may not coalesce into a common ancestor until they reside in the same population, and the time until this occurs is affected by migration patterns and population split times. 2. At any particular point in time, two members within the same population are more likely to have a common parent if the population size is small; so, for example, residents of a small village will typically be more closely related than residents of a large city.[/b] The split time of the [b]ghost Basal Eurasian[/b] lineage from other Eurasians was inferred at 79.8 kya (95% CI of 67.4-101 kya). Other parameters were broadly in line with previous estimates, such as a Mbuti-Eurasian split of 96 kya, a Han-European split of 50 kya, a Neanderthal split of 696 kya, and Eurasians deriving 0.03 of their ancestry from Neanderthal (Terhorst et al., 2017; Green et al., 2010; Meyer et al., 2016). [/QUOTE] [/QB][/QUOTE]
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