tag:blogger.com,1999:blog-7785493.post4003052014148977633..comments2024-01-04T04:11:55.717+02:00Comments on Dienekes’ Anthropology Blog: Toba eruption did not cause volcanic winter in Africa ~75kaDienekeshttp://www.blogger.com/profile/02082684850093948970noreply@blogger.comBlogger6125tag:blogger.com,1999:blog-7785493.post-54748973050013817492013-05-22T05:46:04.883+03:002013-05-22T05:46:04.883+03:00Exactly, Wil. The evidence appears to rule out a b...Exactly, Wil. The evidence appears to rule out a bottleneck in Africa, but says nothing about a bottleneck centered in South Asia, as posited by Stephen Oppenheimer -- and suggested (though not confirmed) by Petraglia's research.DocGhttps://www.blogger.com/profile/17359004200002936544noreply@blogger.comtag:blogger.com,1999:blog-7785493.post-84755064512772446722013-05-21T01:43:12.405+03:002013-05-21T01:43:12.405+03:00"The YTT in Lake Malawi is not accompanied by..."The YTT in Lake Malawi is not accompanied by a major change in sediment composition or evidence for substantial temperature change, implying that the eruption did not significantly impact the climate of East Africa"... okay fine.<br />..."and was not the cause of a human genetic bottleneck at that time." Does not follow.Wilhttps://www.blogger.com/profile/03139893226825865757noreply@blogger.comtag:blogger.com,1999:blog-7785493.post-60279067310913422042013-05-19T22:44:27.940+03:002013-05-19T22:44:27.940+03:00As far as the "Hobbits" are concerned, i...As far as the "Hobbits" are concerned, it's important to remember that the prevailing winds were in a northwesterly direction. Relatively little Toba tuff has been found east or south of Sumatra.DocGhttps://www.blogger.com/profile/17359004200002936544noreply@blogger.comtag:blogger.com,1999:blog-7785493.post-33257703009605369852013-05-19T22:40:48.669+03:002013-05-19T22:40:48.669+03:00From Chapter Ten of my (online) book, Sounding the...From Chapter Ten of my (online) book, Sounding the Depths (http://soundingthedepths.blogspot.com/2011/03/chapter-ten-bottleneck.html):<br /><br />[Stanley] Ambrose was . . . the first to suggest that Toba could have been responsible for human differentiation, producing the various “races” and other signs of major biological and cultural diversity. However, if all humans were confined to Africa when Toba hit, as Ambrose assumes, it's impossible to see how any differences produced by that event could have evolved into the worldwide distinctions so evident today, of which Africa is a relatively homogeneous part. Toba can explain the large-scale differentiation patterns we now see only if humans had already left Africa and had occupied most or all of the south Asiatic coast by the time it erupted. However, Ambrose, for reasons that continue to puzzle me, insists that this is not possible and that all the archaeological evidence points to an African exodus after the Toba eruption, not before (personal communication).DocGhttps://www.blogger.com/profile/17359004200002936544noreply@blogger.comtag:blogger.com,1999:blog-7785493.post-26875922580047923212013-05-18T09:33:24.552+03:002013-05-18T09:33:24.552+03:00Well, -1.5 C may not be significant in East Africa...Well, -1.5 C may not be significant in East Africa, but it <i>can</i> be in climates that are already marginal (and where the cooling might have been more extreme).<br /><br />But, more importantly, this does not change the fact that climate ooA deteriorated during and after this time, and soon also became much dryer - making the time period ~70,000 - 55,000 ya one of the worst possible for a successful ooA or out of Arabia movement.eurologisthttps://www.blogger.com/profile/03440019181278830033noreply@blogger.comtag:blogger.com,1999:blog-7785493.post-24327135193244260252013-05-17T02:47:19.233+03:002013-05-17T02:47:19.233+03:00"The YTT in Lake Malawi is not accompanied by..."The YTT in Lake Malawi is not accompanied by a major change in sediment composition or evidence for substantial temperature change, implying that the eruption did not significantly impact the climate of East Africa and was not the cause of a human genetic bottleneck at that time". <br /><br />And the survival of the 'Hobbits' in Flores suggests it had a minor influence even near the eruption centre. I think people just like the idea of natural disasters. A hangover from 'end of the world' religious beliefs? terrythttps://www.blogger.com/profile/17327062321100035888noreply@blogger.com