tag:blogger.com,1999:blog-3734925856292601239.post3388320082969912322..comments2024-03-22T15:55:34.030-04:00Comments on Evo and Proud: Are we all Middle Easterners now?Peter Frosthttp://www.blogger.com/profile/04303172060029254340noreply@blogger.comBlogger5125tag:blogger.com,1999:blog-3734925856292601239.post-66009400501547755942009-11-05T10:20:48.673-05:002009-11-05T10:20:48.673-05:00What did look like these farmers ?What did look like these farmers ?Robert8noreply@blogger.comtag:blogger.com,1999:blog-3734925856292601239.post-74025571932260173822009-11-04T16:37:16.746-05:002009-11-04T16:37:16.746-05:00Ancient DNA mutations permitted humans to adapt to...<a href="http://www.scienceblog.com/cms/node/2167" rel="nofollow">Ancient DNA mutations permitted humans to adapt to colder climates</a>.<br /> End of the Ice Age would have led to a relatively swift transition to selection against cold adapted mitochdria which may lower fertility in men..<br /> <a href="http://mathildasanthropologyblog.wordpress.com/2008/11/25/otzi-the-icemans-mitochondrial-dna/" rel="nofollow">Otzi the Iceman’s mitochondrial DNA</a>.<br />Close examination of his mitochondrial DNA showed mutations associated with low sperm mobility, so it’s possible he was infertile. The more interesting thing about his mt DNA is that it is a previously unseen variant of K1, and it’s quite possibly extinct in the modern European population.<br /><br />Ice Age mtDNA may have died out over thousands of years.Todnoreply@blogger.comtag:blogger.com,1999:blog-3734925856292601239.post-15266292368769622812009-10-30T19:38:16.484-04:002009-10-30T19:38:16.484-04:00I'm wasn't suggesting a mass die off over ...I'm wasn't suggesting a mass die off over a couple of generations that left a few suvivors. Say certain mtDNA lines could produce 10% higher fitness in the new situation of high carb diet diet and epidemics of novel infectious diseases brought by incomers. Over <i>many</i> generations the adaptive mtDNA would supplant the others, gradually becoming the norm. <br /><br />Would the Kurgan hypothesis be a viable alternative explaination?Todnoreply@blogger.comtag:blogger.com,1999:blog-3734925856292601239.post-7929653753900429642009-10-30T18:06:00.258-04:002009-10-30T18:06:00.258-04:00Tod,
The Inuit have made the transition from a lo...Tod,<br /><br />The Inuit have made the transition from a low to high carbohydrate diet in two or three generations. There have been negative effects, and I don't want to minimize them, but the most serious ones seem to be due to overeating.<br /><br />There seems to have been a period of a thousand years or so when the northward movement of hunter-gatherers stalled. There may have been trade between the two groups and this may have allowed some hunter-gatherers to become habituated to cereal foods.Peter Frostnoreply@blogger.comtag:blogger.com,1999:blog-3734925856292601239.post-53587209511064817372009-10-30T12:34:47.394-04:002009-10-30T12:34:47.394-04:00Hunter gatherers in Europe would have been adapted...Hunter gatherers in Europe would have been adapted to eating a diet very low in carbohydrates<br /><br />The switch to agriculture may have significantly disadvantaged most of the European 'low-carb' hunter gatherer mtDNA lines to the extent of them disappearing over thousands of years. European mtDNA that is around today may well have been inherited from far less than 5% of the ancestral hunter gatherer women. It is not terribly surprising that a sample of 20 failed to find a match with later agriculturists.<br /><br /><b>"The ‘winners’ were semi-sedentary coastal groups with relatively high population densities. Because such groups depended more on fishing and sealing than on hunting and gathering, they could more readily integrate farming into their lifestyle, if only as a secondary subsistence activity. They were also more numerous and likelier to withstand encroachment by farming communities"</b><br /><br />Populations which were not so adapted to eating meat, ie those on on the southern periphery of the steppe-tundra hunting area, may have been the source of the mtDNA that later became predominant.<br /><br /> Alternatively, Dienkes' Middle Eastern farmers could have supplied the necessary agriculture adapted mtDNA. As the Middle Eastener's non-mitochondrial DNA was not being selected for in the same way it would never have achieved the same displacement of the hunter gatherer's non mitochondrial DNA. <br /><br /><a href="http://www.ncbi.nlm.nih.gov/pubmed/17551080" rel="nofollow">Mitochondrial DNA haplogroups and type 2 diabetes: a study of 897 cases and 1010 controls</a> "[...]it is shown that European mtDNA haplogroups are unlikely to play a major role in the risk of developing the disorder."<br /><br /><a href="http://www.ncbi.nlm.nih.gov/pubmed/17273962" rel="nofollow">Mitochondrial haplogroup N9a confers resistance against type 2 diabetes in Asians</a><br /><br /><a href="http://www.ncbi.nlm.nih.gov/pubmed/17259400" rel="nofollow">Women with mitochondrial haplogroup N9a are protected against metabolic syndrome</a><br /><br /><a href="http://johnhawks.net/weblog/reviews/neandertals/neandertal_dna/ruiz-pesini_selection_mtdna_2004.html" rel="nofollow">Mitochondrial DNA adaptations in living human populations (John Hawkes)</a>.<br /><br />"The occurrence of potentially adaptive mtDNA mutations appears to have been quite a common event throughout human prehistory, because today's haplogroups appear to be separated by many mutations that are adaptive in different contexts."Todnoreply@blogger.com