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Genetic Closeness of the East/West African SNP population clusters (blog source)
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[QUOTE]Originally posted by Gor: [QB] [QUOTE]Originally posted by the lioness,: [qb] [QUOTE]Originally posted by Gor: There are virtually no genetic clusters. They most commonly appear by error if you polarize genetic data by excluding 'intermediate' populations (note the plot and tree diagrams above exclude many): "[T]he inclusion of such [intermediate] samples demonstrates geographic continuity in the distribution of genetic variation and thus undermines traditional concepts of race." - Bamshad, Michael J., Wooding, Stephen, Salisbury, Benjamin A., & Stephens, J. Claiborne. 2004. "Deconstructing the relationship between genetics and race". Nature Reviews Genetics, 5,. 598–609 [/QUOTE]However, somebody who makes this continuity argument would subscribe to the OOA theory but you on the other hand are a multiregionalist Therefore clustering under such a scenario would be even more pronounced, there would be no ancestral connections between the regions, no overlap between these populations, no continuity [/qb][/QUOTE]No connections, or continuity between regions? You appear to misunderstand Multiregional evolution, which is based on inter-regional gene flow via a global isolation by distance model (IBD) within a single polytypic species: "It would therefore appear that an isolation-by-distance model is one possible resolution of the different sources of data addressing human origins. It should be noted that such a model is not merely consistent with multiregional evolution, [i]it is multiregional evolution[/i] (Wolpoff et al., 1984; Relethford, 1998; Templeton, 1998, emphasis in original)." ( [URL=http://repositriodeficheiros.yolasite.com/resources/Texto%2027.pdf]Hawks & Wolpoff[/URL], 2001) According to IBD, genetic similarity between populations decreases as the geographic distance between them increases. However the measure of 'similarity' is relative to population size, i.e. if you have a much larger population, more genes are going to spread out from there. The population in Africa was far larger throughout the Pleistocene than any other continent, so Multiregionalism only discusses those very few traits that show a spatial or geographical frequency distribution by drift, or selection: [QUOTE]My findings may seem contradictory to the prediction of regional continuity under a multiregional model, which is that the greatest similarity over time will be within regions. However, this prediction would be contradictory only if we expect all traits to show a pattern of regional continuity. However, proponents of the multiregional model do not suggest that all traits will show continuity. [b]In reality, regional continuity is expected only for some traits as the result of genetic drift and selection acting to maintain high frequencies of a trait within a region[/b].[/QUOTE]- [URL=http://content.csbs.utah.edu/~rogers/ant6299/readings/Relethford-EA-8-7.pdf]Relethford[/URL] (1998) And this is why Multiregionalism chooses to only focus on the world perhiperies or what it calls "edges" e.g. Europe, North-East Asia and Indonesia or Australia. Here populations were the smallest throughout the Pleistocene, and regional continuity is easier to detect in the fossil record. Most palaeo-anthropologists however now agree there is far less regional continuity than was first proposed by Wolpoff, Wu and Thorne. Instead of 10+ skeletal traits, it is now looking only 2-4 per each region. This is why Stringer recently wrote Multiregionalism has "shifted close to that of the Assimilation Model". [/QB][/QUOTE]
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