tag:blogger.com,1999:blog-7785493.post5502921461316364966..comments2024-01-04T04:11:55.717+02:00Comments on Dienekes’ Anthropology Blog: Campbell & Tishkoff review paper on African genetic diversityDienekeshttp://www.blogger.com/profile/02082684850093948970noreply@blogger.comBlogger5125tag:blogger.com,1999:blog-7785493.post-84552777527834049662008-07-11T08:12:00.000+03:002008-07-11T08:12:00.000+03:00Autosomal studies seem to yield a too recent pictu...Autosomal studies seem to yield a too recent picture of groupings. They are complementary certainly, at least when they yield sufficiently deep bayesian K-means analysis, but they can't replace halpid genetics at all. <BR/><BR/>Overall one of the main problems I've seen in autosomal genetic studies is most visible in PC analysis, where locally important components are just ecclipsed by the overall most sampled ones. This also happens in low depth K-means structure, and maybe even in middle depth one. <BR/><BR/>In other words, if you are studying a region like West Eurasia and there is, say an specifical Saami component that makes up like 80% of their autosomal structure it's very likely that it won't show up in the continental/subcontinental structure at all, except at pretty deep structure. But very few autosomal studies do that. I have only read one of those that reched K=16 and was about Native Americans. Normally they tend to remain at the surface, what obviously only yields very shallow results. <BR/><BR/>The structure also varies a lot with samples and recently it's been strongly recommended (this month's PLOS Genetics) to expand samples for better results when possible.Majuhttps://www.blogger.com/profile/12369840391933337204noreply@blogger.comtag:blogger.com,1999:blog-7785493.post-29225661394974292482008-07-11T07:24:00.000+03:002008-07-11T07:24:00.000+03:00I've been trying to get through to you for ages th...I've been trying to get through to you for ages that mtDNA (or Y-chromosome) on its own is totally inadequate to draw conclusions from. Autosomal studies are a necessary consideration too.terrythttps://www.blogger.com/profile/17327062321100035888noreply@blogger.comtag:blogger.com,1999:blog-7785493.post-13661527432668757382008-07-10T22:36:00.000+03:002008-07-10T22:36:00.000+03:00I am not implying anything: I haven't read the pap...I am not implying anything: I haven't read the paper. <BR/><BR/>Are you implying that autsomal studies are some sort of holy grail? I don't think that certainly, much less without reading the study.Majuhttps://www.blogger.com/profile/12369840391933337204noreply@blogger.comtag:blogger.com,1999:blog-7785493.post-88972435596531480682008-07-10T12:17:00.000+03:002008-07-10T12:17:00.000+03:00"more than could be infered from mtDNA". Maju. A..."more than could be infered from mtDNA". Maju. Are you implying that mtDNA might not be the perfect measure of population origin and diversity?terrythttps://www.blogger.com/profile/17327062321100035888noreply@blogger.comtag:blogger.com,1999:blog-7785493.post-83038584311363692632008-07-10T10:58:00.000+03:002008-07-10T10:58:00.000+03:00Looks like a very interesting paper, pity it's beh...Looks like a very interesting paper, pity it's behind a paywall. <BR/><BR/>13 ancestral populations is quite a good number of them, more than could be infered from mtDNA, for instance. It's no surprise, I'll add, that NE Africans (Horners, I assume) are more closely related to Eurasians than any other group.Majuhttps://www.blogger.com/profile/12369840391933337204noreply@blogger.com