tag:blogger.com,1999:blog-7785493.post1377816548176472280..comments2024-01-04T04:11:55.717+02:00Comments on Dienekes’ Anthropology Blog: Population-specific SNPs and archaic admixture in Homo sapiensDienekeshttp://www.blogger.com/profile/02082684850093948970noreply@blogger.comBlogger9125tag:blogger.com,1999:blog-7785493.post-58851567022416667202012-09-05T06:40:29.162+03:002012-09-05T06:40:29.162+03:00"The admix pattern seems to be unique to the ..."The admix pattern seems to be unique to the Americas, so something 'peculiar' must have been going on in Siberia at the time". <br /><br />Not necessarily 'at the time'. We have had a huge expansion of Y-DNA NO in the east, as well as continued expansion of M-derived mt-DNAs. This series of expansions from a small region in East Asia would easily explain the limited evidence for Denisovan admixture through Central Asia today while leaving open its survival in America. terrythttps://www.blogger.com/profile/17327062321100035888noreply@blogger.comtag:blogger.com,1999:blog-7785493.post-17541800751700589162012-09-04T18:32:10.974+03:002012-09-04T18:32:10.974+03:00So modern humans evolved into existence in Eurasia...So modern humans evolved into existence in Eurasia through new mutations and natural selection and modern genes later spread into Africa through admixture and selection? Modern humans didnt come "out" of Africa but human modernity spread into there? Which Africans would be least effected by genetic modernity, pygmies?<br /><br />Rather than "we are all Africans", it might be better to say "we are all modern Eurasians but some more so than others"?apostateimpressionshttps://www.blogger.com/profile/08992369104954433139noreply@blogger.comtag:blogger.com,1999:blog-7785493.post-60840001183702500792012-09-04T03:13:10.388+03:002012-09-04T03:13:10.388+03:00"That view came about because of the Victoria..."That view came about because of the Victorian idea of 'survival of the fittest', originally an economic justification that became more widely applied. From that it was next assumed that new species arose from the expansion of suddenly 'superior' groups, completely ignoring the concept of inbreeding depression."<br /><br />Nothing has really changed other than the amount of time our ancestors could evolve away from each other.princenuadhahttps://www.blogger.com/profile/02165977957244158593noreply@blogger.comtag:blogger.com,1999:blog-7785493.post-26433042589414495922012-09-03T22:56:34.172+03:002012-09-03T22:56:34.172+03:00"What can you say about archaic admixture in ..."What can you say about archaic admixture in Amerindians?"<br /><br />I also believe that's a crucial issue (with wide implications for the peopling of Eurasia) that unfortunately few people have considered so far. Amerinds are an important part of the admix evidence, because they've been isolated for so long and so might have preserved things that were lost elsewhere.<br /><br />---------------------<br /><br />The admix signal there is quite high for both Denisova and Neander, specially in (more isolated) South America, IIRC. <br />Is this a refugium effect or what? <br />The admix pattern seems to be unique to the Americas, so something "peculiar" must have been going on in Siberia at the time.<br /><br />BUT, the alternative, of course, is that nothing much happened at all, and the high "archaic admixture" signal in the Americas and Australasia is in fact a lack of later African admixture. <br /><br />More likely, both hypotheses have some truth to them, and "which one is right" will be a matter of degree rather than an absolute answer.aramthttps://www.blogger.com/profile/04486006044411081900noreply@blogger.comtag:blogger.com,1999:blog-7785493.post-58414897876984491292012-09-03T18:04:54.534+03:002012-09-03T18:04:54.534+03:00What can you say about archaic admixture in Amerin...What can you say about archaic admixture in Amerindians?<br />Horatiohttps://www.blogger.com/profile/00891591053238760399noreply@blogger.comtag:blogger.com,1999:blog-7785493.post-58083214052291713212012-09-03T17:06:05.217+03:002012-09-03T17:06:05.217+03:00among Eurasians
Here I should have written "...<i>among Eurasians</i><br /><br />Here I should have written "among non-Africans".Onur Dincerhttps://www.blogger.com/profile/05041378853428912894noreply@blogger.comtag:blogger.com,1999:blog-7785493.post-84942869965508225232012-09-03T13:55:15.728+03:002012-09-03T13:55:15.728+03:00The easy part is understood. What about the harder...The easy part is understood. What about the harder part, i.e., the differences in the amount of Neanderthal admixture among Eurasians and also among Africans?Onur Dincerhttps://www.blogger.com/profile/05041378853428912894noreply@blogger.comtag:blogger.com,1999:blog-7785493.post-70347114047338708102012-09-03T06:10:12.838+03:002012-09-03T06:10:12.838+03:00Great Job.Great Job.Nirjhar007https://www.blogger.com/profile/12880827026479135118noreply@blogger.comtag:blogger.com,1999:blog-7785493.post-50462606238683819552012-09-03T05:55:53.259+03:002012-09-03T05:55:53.259+03:00"The implication is direct: regional-specific..."The implication is direct: regional-specific variation in humans is in part the heritage of regional continuity in both Africa and Eurasia. However it was that H. sapiens came to dominate our planet, it was not by extinction of archaic humans". <br /><br />Nice one. The 'regional continuity' people were correct, at least to some extent. <br /><br />"Until quite recently, it was near-universally thought that modern humans are the descendants of a single recent African population. Differences between human groups were ascribed to the operation of genetic drift, natural selection, and new mutation, as modern humans left their primordial Eden and expanded to populate the rest of the globe. According to this model: humans became more different from each other over time". <br /><br />That view came about because of the Victorian idea of 'survival of the fittest', originally an economic justification that became more widely applied. From that it was next assumed that new species arose from the expansion of suddenly 'superior' groups, completely ignoring the concept of inbreeding depression. <br /><br />"Low genetic diversity of Denisova hominin, consistent with a model in which human diversity is generated by admixture between populations with low intra-group (as in Denisova), but high inter-group diversity (see point #2)". <br /><br />I think everything is related to your 'point 3' with the proviso that point 3 is similar to point 2. <br /><br />"Higher genetic divergence between Denisova and Vindija (across ~6Mm of distance) than between any two living humans from the entire globe". <br /><br />Makes sense. Ancient humans are likely to have been far more geographically diverse that are modern humans because they are likely to have been less mobile.terrythttps://www.blogger.com/profile/17327062321100035888noreply@blogger.com