tag:blogger.com,1999:blog-7785493.post4447695495420817224..comments2024-01-04T04:11:55.717+02:00Comments on Dienekes’ Anthropology Blog: Tales of Neanderthal admixture in modern EurasiansDienekeshttp://www.blogger.com/profile/02082684850093948970noreply@blogger.comBlogger68125tag:blogger.com,1999:blog-7785493.post-46920301194780596602010-05-19T01:50:00.847+03:002010-05-19T01:50:00.847+03:00Thorstein: As of now it's known that Neanderth...Thorstein: As of now it's known that Neanderthals inhabited in West Asia and Central Asia, in addition to Europe. There's no trace of them in East or South Asia, nor of their favorite technology: Mousterian.Majuhttps://www.blogger.com/profile/12369840391933337204noreply@blogger.comtag:blogger.com,1999:blog-7785493.post-35045516979575031602010-05-18T19:33:27.210+03:002010-05-18T19:33:27.210+03:00This might be a stupid question, but with how much...This might be a stupid question, but with how much certainty do we know that Neanderthals were confined to Europe? That seems strange to me, given that the rest of Eurasia has a similar climate and ecosystem. If they could find a niche in Europe, why couldn't they find a niche in Central and East Asia as well? We also know that historically, most Paleontologists have come from Europe... <br /><br />And, to the extent that Neanderthals were not confined to Europe, then it's not strange that we find their genes roughly equally present in all non-African DNA...Doug Campbell https://www.blogger.com/profile/11028049845008665877noreply@blogger.comtag:blogger.com,1999:blog-7785493.post-20878863421402133812010-05-11T08:07:39.262+03:002010-05-11T08:07:39.262+03:00"Perhaps the mutations were selected in colde..."Perhaps the mutations were selected in colder climates and perhaps the population that migrated to Papua New Guinea experienced colder climates prior to arriving there".<br /><br />By the well attested coastal (tropical) route?!<br /><br />Perhaps... not. <br /><br />We are talking of alleles that are in the derived state in Neanderthals in comparison with modern humans and chimpanzees. It's not an archaism but an innovation: a Neanderthal-specific innovation.Majuhttps://www.blogger.com/profile/12369840391933337204noreply@blogger.comtag:blogger.com,1999:blog-7785493.post-15247644627829247282010-05-11T06:30:40.306+03:002010-05-11T06:30:40.306+03:00That would demand a selective mechanism that you h...<i>That would demand a selective mechanism that you have failed to describe. Climatically and so on, PNG is much more like Nigeria than either is like Europe.</i><br /><br />Perhaps the mutations were selected in colder climates and perhaps the population that migrated to Papua New Guinea experienced colder climates prior to arriving there.<br /><br /><i>There's a long AFRICAN history for the line leading to H. sapiens alone after such thing happened.</i><br /><br />The long African history explains why there was enough time for the mutations to decline to only 1 to 4% in the population that became Eurasians. Perhaps one can look at these mutations as a clock measuing the time when a group left Africa. Neanderthals hundreds of thousands of years ago, so they had lots of the mutations, Eurasians only 60 K ago so they had only 1 to 4%, and Africans never, so they have 0%. But I'm speculating with a limited grasp of these issues so I apologize for any logical errors.catpersonhttps://www.blogger.com/profile/00648652809818262153noreply@blogger.comtag:blogger.com,1999:blog-7785493.post-995061511525200372010-05-11T06:11:12.576+03:002010-05-11T06:11:12.576+03:00"... they would have gradually lost the mutat..."... they would have gradually lost the mutations in the last 60,000 years if it was only being selected outside Africa".<br /><br />That would demand a selective mechanism that you have failed to describe. Climatically and so on, PNG is much more like Nigeria than either is like Europe.<br /><br />"My argument is that is NOT an admixture episode since I'm arguing that it occured before the ancestors of modern humans and neanderthals diverged into separate groups".<br /><br />There's a long AFRICAN history for the line leading to H. sapiens alone after such thing happened. Longer than all the time passed since the OoA, even in the most recentist scenarios. <br /><br />It's not logical at all.Majuhttps://www.blogger.com/profile/12369840391933337204noreply@blogger.comtag:blogger.com,1999:blog-7785493.post-20861282438007919972010-05-11T05:07:13.335+03:002010-05-11T05:07:13.335+03:00I understand that the population from which the Oo...<i>I understand that the population from which the OoA group(s) splintered is best described by mtDNA haplogroup L3. This lineage expaned in Africa at that same time and is very important in all African peoples except a handful of isolated hunter-gatherer surviors, such a the Bushmen. <br /><br />That means that if there was structure in Africa prior to the OoA in that sense, Yorubas must have anywhere between 25-100% the Nenaderthal component Eurasians show.</i><br /><br />I don't think so because Yorubas stayed in Africa so they would have gradually lost the mutations in the last 60,000 years if it was only being selected outside Africa.<br /><br />My argument is that these mutations first occured in the population that is ancestral to both neanderthals and modern humans but since they were only useful outside Africa, they gradually decreased the longer folks stayed in Africa. Since neanderthals were the first descendants of the ancestral population to leave Africa, they preserved the mutations at the highest frequency. Since modern human Eurasians left Africa much later, they only carried small amount of the mutations (1 to 4%) and since Yorubas & bushmen never left Africa, they completely lost the mutation. <br /><br /><i>So this admixture episode did not happen in Africa, at least not south of the Sahara</i><br /><br />My argument is that is NOT an admixture episode since I'm arguing that it occured before the ancestors of modern humans and neanderthals diverged into separate groups. Mixing implies two different populations came together, but I'm arguing they were the same population when the mutations emerged.catpersonhttps://www.blogger.com/profile/00648652809818262153noreply@blogger.comtag:blogger.com,1999:blog-7785493.post-57541504992787875152010-05-11T03:57:46.604+03:002010-05-11T03:57:46.604+03:00"But my argument is that perhaps the mutation..."But my argument is that perhaps the mutations entered the human line right before the ancestors of neanderthals left Africa hundreds of thousands of years ago"<br /><br />That's model 4: pre-existent structure in Africa that the authors say the can't disprove but seems less likely. <br /><br />I understand that the population from which the OoA group(s) splintered is best described by mtDNA haplogroup L3. This lineage expaned in Africa at that same time and is very important in all African peoples except a handful of isolated hunter-gatherer surviors, such a the Bushmen. <br /><br />That means that if there was structure in Africa prior to the OoA in that sense, Yorubas must have anywhere between 25-100% the Nenaderthal component Eurasians show. And that is not the case at all. <br /><br />So this admixture episode did not happen in Africa, at least not south of the Sahara (there's a chance that the episodes of Palestine permeated to Egypt, where some Mousterian is also found AFAIK).Majuhttps://www.blogger.com/profile/12369840391933337204noreply@blogger.comtag:blogger.com,1999:blog-7785493.post-59798922576436249612010-05-10T21:05:03.825+03:002010-05-10T21:05:03.825+03:00That can be totally discarded, I understand. If so...<i>That can be totally discarded, I understand. If so we'd see them in Africa in differential form, with Yorubas (high in Y-DNA E and mtDNA L3, i.e. closely related to Eurasians) having them at least in some apportions and Bushmen not. This simply does not happen, so your scenario is practically impossible.</i><br /><br />But my argument is that perhaps the mutations entered the human line right before the ancestors of neanderthals left Africa hundreds of thousands of years ago (and preserved in neanderthals who needed them out of Africa), thus would have gradually decreased in Africa because they had little or no selective advantage there. By the time modern humans first left Africa about 60 thousand years ago, they may have decreased in Africa to only 1-4% and preserved at this level in non-African modern human populations because of their selective advantage in non-African environments. Meanwhile they continued to decrease (eventually to 0%) in Africans where they continued to be useless. <br /><br /><i>And why would they have no value in Africa and have it in New Guinea? Beats me!</i><br /><br />Perhaps the ancestors of those who live in New Guinea had some exposure to colder climates as they moved to New Guinea. Some probably came from East Asia.catpersonhttps://www.blogger.com/profile/00648652809818262153noreply@blogger.comtag:blogger.com,1999:blog-7785493.post-68659760928817235242010-05-10T20:48:06.790+03:002010-05-10T20:48:06.790+03:00Not sure why do you say that "stress triggers...<i>Not sure why do you say that "stress triggers mutations". I can conceive that stress emphasizes selection, destroying those less apt maybe, but why would it cause mutations as such?</i><br /><br />Wasn't there a major revision of evolutionary theory a few years back that found that mutations are not simply random but rather they are more probable in organisms that are stressed. Evolutions way of increasing the odds that an organism that is having trouble adapting will have a better chance of mutating into a form better suited to its environment. It was a big deal at the time because it suggested that Lamarkism might not have been totally wrong.catpersonhttps://www.blogger.com/profile/00648652809818262153noreply@blogger.comtag:blogger.com,1999:blog-7785493.post-52222558070685617672010-05-10T19:51:04.362+03:002010-05-10T19:51:04.362+03:00"Now I have to worry about how much Neanderth..."Now I have to worry about how much Neanderthal I have in me and what that means"<br /><br />hahahaha, I had the same reaction... its just a natural thought. seeing how it's basically just a Eurasian thing I'm not concerned.princenuadhahttps://www.blogger.com/profile/02165977957244158593noreply@blogger.comtag:blogger.com,1999:blog-7785493.post-23926279250553469462010-05-10T18:09:58.138+03:002010-05-10T18:09:58.138+03:00It's worthwhile looking at the book Reticulate...It's worthwhile looking at the book Reticulate Evolution by Arnold, in which all the reported cases of "introgression" between "archaics" and modern humans are cataloged and analyzed. Available on Google books.<br /><br />What's interesting about these studies is that the highest frequencies of those "introgressed" alleles are often reported from American Indians. I'm sure if American Indians were in Green's sample, they would have been by a tad closer to Neanderthals than the Chinese. For instance, haplogroup B of human lice DNA, which is found mostly in North and South America and which diverged from more frequent haplotype A about 1.2 MM years ago, is claimed by Reed et al. 2004 to have been introduced into modern humans through a "reproductive contact" with Asian Homo erectus. Later the same haplogroup B was detected in Europeans and Australian aborigines (these are our Eurasian humans from Green et al. 2010) but not in Africa. See Light et al. 2008; Raoult et al. 2008.German Dziebelhttps://www.blogger.com/profile/10703679732205862495noreply@blogger.comtag:blogger.com,1999:blog-7785493.post-5870200151337843422010-05-10T15:45:48.659+03:002010-05-10T15:45:48.659+03:00"Are we talking about old genes that got pres..."Are we talking about old genes that got preserved in Eurasia but not in Africa, or new adaptations/changes in Eurasia?"<br /><br />If I'm correct, what the authors have measured is alleles that were mutated in Neanderthals and not in all humans with relation to the Pan-Homo common ancestor. <br /><br />Are you saying this is mere adaptative noise? What's in Yemen that is not in Eritrea? What's in Palestine that is not in Egypt? What's in Indonesia that is not in Congo? <br /><br />I fail to see the need for adaptation in the journey from the Nile to the Jordan. And I fail to see how European Neanderthals would have been better adapted to those southern Asian climates than AMHs who lived in North Africa and Ethiopia since some 190 Ka ago (attested by the archaeological record). <br /><br />"So, IMO the ~2% the authors see is largely stuff that first surfaced and accumulated in Eurasia over the past ~million years, so the short name "Neanderthal" is not all that misleading if we all accept them to derive from Heidelbergensis in significant isolation from Africa".<br /><br />It's not. After all Neanderthals are the ones providing the reference - and most likely admixture happened with them anyhow, because we know that there were contacts in the Middle East 100-plus Ka ago.Majuhttps://www.blogger.com/profile/12369840391933337204noreply@blogger.comtag:blogger.com,1999:blog-7785493.post-53418491409418544672010-05-10T11:51:15.623+03:002010-05-10T11:51:15.623+03:00This last possibility is also perfectly viable, sp...<i>This last possibility is also perfectly viable, specially if we accept that Neanderthals and us diverged some 900 Ka ago. and not just that ridiculous figure of 300 Ka. (please, we would not have become so radically different is such a short time!) from some variant of H. ergaster/erectus that was carrier of Acheulean technology. If so, what we see as "Neanderthal" genes would rather be general Eurasian Homo spp. genes, distinct from the African ones that predominate in our species. </i><br /><br />Of course, we have to be a bit careful here. Are we talking about old genes that got preserved in Eurasia but not in Africa, or new adaptations/changes in Eurasia?<br /><br />I think the second option is much more likely, since I would maintain that there was a much larger gene pool in Africa, actually preserving <i>more</i> ancient genes than Eurasia could (unless perhaps we go back to erectus, which would also necessitate Neanderthal-erectus interbreeding to shuffle those genes first into Neanderthal, and then again ending up with likely just too little material left to transfer to AMHs).<br /><br />So, IMO the ~2% the authors see is largely stuff that first surfaced and accumulated in Eurasia over the past ~million years, so the short name "Neanderthal" is not all that misleading if we all accept them to derive from Heidelbergensis in significant isolation from Africa.<br /><br /><i>In other words: would you let your daughter marry a N Neanderthal? Would she find him attractive? Same for guys. The answer is most probably no. </i><br /><br />Hehe... I always find it sooo seductive to day-dream (i.e., write imaginary screen plays) about possible scenarios. <br /><br />Let's not forget the wallflower one. You know, there is that truly helpful, polite, yet quiet Neanderthal boy that got adopted after he showed the thirsty clan the much-needed fresh water source. Given your somewhat ugly and simply too smart daughter that no one wants to take even as second or third wife, perhaps not a bad choice? What father could resist? ;)eurologisthttps://www.blogger.com/profile/03440019181278830033noreply@blogger.comtag:blogger.com,1999:blog-7785493.post-42136244486533847822010-05-10T11:20:15.167+03:002010-05-10T11:20:15.167+03:00"But we already have strong (though not concl..."But we already have strong (though not conclusive) mitochondrial evidence that breeding did not occur"...<br /><br />Nope. The mtDNA data was no evidence of interbreeding but could never totally rule out such possibility, just made it less likely and surely not large. <br /><br />What Green et al. have found now is not large, so it fits perfectly with the mtDNA evidence. Minor admixture would not normally leave any evidence in the haploid lineage pool because these tend to get fixated in the majority clades, not the odd ones, by mere statistical logic. But, by the same statistical logic, all ancestors, Neanderthal included, have their proportional chance to leave an overall genetic mark according to their numerical relevance at the original events (OoA period in this case). <br /><br />So most likely 1-4% of Neanderthal-specific alleles means 1-4% (roughly) of Neanderthal ancestry.<br /><br />"... and the two populations were isolated for so long that makes us think they could breed even if they wanted to?"<br /><br />A lot of closely related species can interbreed. Even some belonging to different genus, such as lion and tiger. However this never (or almost never) happens in the wild (but polar and grizzly bears do interbreed occasionally in North America naturally). <br /><br />Neanderthals and Sapiens were either two closely related different species or two very distinct different subspecies of the same species. This is arguable but the discussion on the biological classification should not obscure the fact that they were probably inter-fertile but surely with some barriers also, making such interbreeding difficult, instinctively undesirable and sometimes even not working at all. <br /><br />Even being inter-fertile, being also so different morphologically and surely in customs and psychology, would be a barrier to full assimilation of one species with the other, making it practically difficult. In other words: would you let your daughter marry a N Neanderthal? Would she find him attractive? Same for guys. The answer is most probably no. <br /><br />But there's always someone with odd tastes, you know. And we can't exclude rape as well. <br /><br />And if life along Neanderthals was peaceful and productive for generations, affections and aesthetic preferences, which are largely cultural, learned, should become more favorable, also allowing for intimate situations to happen more frequently. <br /><br />Whatever the case, here it is. The last legacy of Neanderthals.Majuhttps://www.blogger.com/profile/12369840391933337204noreply@blogger.comtag:blogger.com,1999:blog-7785493.post-70591614465521389972010-05-10T11:20:04.795+03:002010-05-10T11:20:04.795+03:00"I don't know much about genetics, but th..."I don't know much about genetics, but this argument sounds counterintuitive to me. Is it really so rare for the same mutations to occur independently?"<br /><br />It is counterintuitive to me that mutations occur in parallel, with exactly the same changes (because of what Eurologist explained: they are random, not pre-selected). <br /><br />However I read recently on certain research on butterflies that indicated that in more than one different species the same mutation had developed independently for the same function. I'm talking from memory but I think they explained this because of functional constrictions because of previously shared evolutionary paths. <br /><br />Anyhow, considering that we don't know at this moment if the Neanderthal alleles in our species are adaptative or merely neutral and that all the rest (or almost) of the Eurasian genome is made up of the pre-existent African diversity, and considering that the distance between Eurasians and Africans is virtually the same for all cases but that is not what happens with the overall genome (where some Africans are clearly closer to Eurasians than others), my opinion is that the Neanderthal origin is almost unquestionable... unless it is H. ergaster/erectus introgression instead. <br /><br />This last possibility is also perfectly viable, specially if we accept that Neanderthals and us diverged some 900 Ka ago. and not just that ridiculous figure of 300 Ka. (please, we would not have become so radically different is such a short time!) from some variant of H. ergaster/erectus that was carrier of Acheulean technology. If so, what we see as "Neanderthal" genes would rather be general Eurasian Homo spp. genes, distinct from the African ones that predominate in our species. <br /><br />This is also possible. But whatever the case, it is almost certain that Eurasian hominins other than H. sapiens are at the origin of that 2% of genes. Otherwise Yorubas would have most of them too, as they are much closer to Eurasians than Bushmen. <br /><br />"Keep in mind that both populations were in a stressful cold environment & stress is now known to trigger mutations".<br /><br />Eurasians migrated by the tropical corridor along the south of Asia. It was never really cold probably yet. Adaptation to cold, essentially techno-cultural, happened upon the scatter of Eurasians, not at the OoA migration - not yet. <br /><br />Not sure why do you say that "stress triggers mutations". I can conceive that stress emphasizes selection, destroying those less apt maybe, but why would it cause mutations as such? <br /><br />"It's also possible that the mutations occured in Africa before the ancestors of humans and neanderthals diverged"...<br /><br />That can be totally discarded, I understand. If so we'd see them in Africa in differential form, with Yorubas (high in Y-DNA E and mtDNA L3, i.e. closely related to Eurasians) having them at least in some apportions and Bushmen not. This simply does not happen, so your scenario is practically impossible. <br /><br />"Meanwhile, the mutations had no value in Africa"...<br /><br />And why would they have no value in Africa and have it in New Guinea? Beats me!<br /><br />Anyhow, they are surely neutral alleles, fixated by random drift in all or most cases.Majuhttps://www.blogger.com/profile/12369840391933337204noreply@blogger.comtag:blogger.com,1999:blog-7785493.post-47878858569530483872010-05-10T09:50:49.274+03:002010-05-10T09:50:49.274+03:00Developing the same exact mutation for a given phe...<i>Developing the same exact mutation for a given phenotype is the extreme exception, not the rule. There are just too many genes involved, and too many possible mutations to reach a similar goal</i><br /><br />I don't know much about genetics, but this argument sounds counterintuitive to me. Is it really so rare for the same mutations to occur independently? Think of all the diseases and syndromes we see that are caused by some random mutation that many unrelated people have the misfortune of being independently afflicted by. <br /><br />And while there are multiple ways of reaching the same goal, some may have a better chance of occuring than others. <br /><br />Further some traits are fairly simple and thus it may be probable that these simple mutations could occur independently in different populations. Keep in mind that both populations were in a stressful cold environment & stress is now known to trigger mutations.<br /><br />It's also possible that the mutations occured in Africa before the ancestors of humans and neanderthals diverged, however the mutations only came under high selection when each population left Africa and needed these mutations to survive the colder climate. Meanwhile, the mutations had no value in Africa and gradually vanished in Africans, thus causing Africans to be genetically less similar to neanderthals than non-Africans are.<br /><br />I just think the results of this study can be interpreted in a number of different ways and people are just jumping to the breeding conclusion because it's interesting and provocative. But we already have strong (though not conclusive) mitochondrial evidence that breeding did not occur, and the two populations were isolated for so long that makes us think they could breed even if they wanted to?catpersonhttps://www.blogger.com/profile/00648652809818262153noreply@blogger.comtag:blogger.com,1999:blog-7785493.post-22847994418629924212010-05-10T06:19:48.678+03:002010-05-10T06:19:48.678+03:00I assume the scientists who did this study ruled o...<i>I assume the scientists who did this study ruled out the possibility that the genetic similarity between non-African humans and neanderthals was not just the result of convergent evolution (i.e. both populations evolving to the Eurasian environment rather than mixing).</i> <br /><br />Developing the same exact mutation for a given phenotype is the extreme exception, not the rule. There are just too many genes involved, and too many possible mutations to reach a similar goal (usually simply enhancing or diminishing some gene expression). Just look at the many mutations for skin, hair, and eye color - and those are quite variable for quick adaptation. Yet, there are tens of ways to do the same (or similar)trick. In less variable genes, or in circumstances where many genes contribute in a very complicated manner, it would be yet much less likely to happen.<br /><br />Thus, parallel evolution rarely brings about the same mutation.<br /><br /><br /><i>If there really was mixing it seems strange that it has not been detected in mitochondrial DNA as usually the dominant population (if it mixes) mates with the females of the conquered population.</i><br /><br />But which population was dominant? The answer is both: Neanderthals were initially more populous, AMHs - at least at one point - seemed to be more flexible and more adaptable through technological (rather than bodily) changes. <br /><br />I also like the dial-step process that Maju is thinking about, just because it can explain very easily why only AMH mt-DNA and Y-DNA survived: the conventional OOA group (~60,000 to 70,000 years ago) was about 50,000 years more modern than the original small band in Palestine, and may have been successful all on their own. Or perhaps, the first migration left no trace, and the second one simply took on and merged with small bands of Neanderthals along the way to India, long before encountering larger Neanderthal groups, say in Turkey or the Balkans or central Europe.eurologisthttps://www.blogger.com/profile/03440019181278830033noreply@blogger.comtag:blogger.com,1999:blog-7785493.post-69562007800855377822010-05-09T20:57:04.162+03:002010-05-09T20:57:04.162+03:00@ catperson :
I've read a comment about it e...@ catperson : <br /><br />I've read a comment about it elsewhere : <br /><br />http://evoandproud.blogspot.com/2010/05/ask-rhino.html?showComment=1273189583416#c5633721397132786148<br /><br /><i>"As for alleles meshing well in such a closely related species: happens often. Taurine and zebu cattle are the result of separate domestications, from stocks of wild cattle that diverged around 500k years ago - more divergent than human and Neanderthals. But zebu genes have introgressing like crazy into an originally taurine African stock - because they work better in the heat and aridity. Creeping zebuization has affected the Middle East as well over the past few thousand years.<br /><br />On the other hand, they don't mesh every time, which is undoubtedly why we don't see any Neanderthal mtDNA or Y-chromsome lineages today. This indicates that Neanderthal mtDNA had a selective disadvantage of, say, half a percent. Plausible if they were energy wasters.<br /><br />By the way, we see cattle populations in Egypt that are a quarter zebu (on autosomal genes) but don't show any zebu mtDNA _or_ y-chromosomes. "</i>Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-7785493.post-37847056181065733882010-05-09T18:16:47.244+03:002010-05-09T18:16:47.244+03:00I assume the scientists who did this study ruled o...I assume the scientists who did this study ruled out the possibility that the genetic similarity between non-African humans and neanderthals was not just the result of convergent evolution (i.e. both populations evolving to the Eurasian environment rather than mixing). If there really was mixing it seems strange that it has not been detected in mitochondrial DNA as usually the dominant population (if it mixes) mates with the females of the conquered population.catpersonhttps://www.blogger.com/profile/00648652809818262153noreply@blogger.comtag:blogger.com,1999:blog-7785493.post-66802809582505426742010-05-09T16:56:04.768+03:002010-05-09T16:56:04.768+03:00"Re. LM3 ("Mungo man"), there's..."Re. LM3 ("Mungo man"), there's been a lot of justified criticism to that old and surely not repeatable test. However I am recalling now the almost forgotten B006 X-DNA lineage that certain studies considered as apparently too old and/or distinct and hence suspicious of differential origin. Does anyone keep a link?"<br /><br />Look up Zietkiewicz et al. Haplotypes in the dystrophin DNA segment point to a mosaic origin of modern human diversity // Am J Hum Genet. 2003 Nov;73(5):994-1015. Earlier on Dienekes: http://dienekes.blogspot.com/2009/05/x-chromosomes-and-settling-of-americas.html.<br /><br />B006 is the basal lineage and it's found at high frequencies in Asia and the Americas and at low frequencies in Africa. Same biogeographic pattern as the shovel-shaped incisors shared by modern humans with Neanderthals. The same pattern is further displayed by the "nuclear insert" (Zischler et al. 1995. A nuclear ‘fossil’ of the mitochondrial D-loop and the origin of modern humans. Nature 378, 489–492) to which the Mungo Man sequence in question was the closest.German Dziebelhttps://www.blogger.com/profile/10703679732205862495noreply@blogger.comtag:blogger.com,1999:blog-7785493.post-86333323571906162332010-05-09T15:52:44.827+03:002010-05-09T15:52:44.827+03:00"Not true, Middle Pleistocene African and Eur..."Not true, Middle Pleistocene African and European hominids belonged to a single taxon that gave birth to both Neandertals and Homo sapiens".<br /><br />That's arguable, not demonstrated. Skeletal biology and molecular clock are not rocket science, you know.<br /><br />And the lack of any such migratory track in the archaeological record after Acheulean makes me suspect that it's wrong.Majuhttps://www.blogger.com/profile/12369840391933337204noreply@blogger.comtag:blogger.com,1999:blog-7785493.post-44674089389618551942010-05-09T15:36:39.592+03:002010-05-09T15:36:39.592+03:00So the situation is:
H. ergaster > H. heidlber...<i>So the situation is:<br /><br />H. ergaster > H. heidlbergensis > Neanderthal<br /><br />H. ergaster > H. rhodesiensis > H. sapiens</i><br /><br />Not true, Middle Pleistocene African and European hominids belonged to a single taxon that gave birth to both Neandertals and Homo sapiens.<br /><br />Katerina Harvati, Petralona: Link Between Africa and Europe? Chapter 2 in New directions in the Skeletal Biology of Greece (eds. L.A. Schepartz, S. C. Fox, C. Bourbou) 2009<br /><br />What you are describing is the accretion hypothesis which is explicitly rejected in the cited book chapter.<br /><br /><i>A new article from John Hawks, which opposes the argument of no interbreeding between sapiens and neanderthals:<br /><br />http://johnhawks.net/weblog/reviews/neandertals/neandertal_dna/african-population-structure-neandertal-mixture-2010.html</i><br /><br />What he observes is easily explained by admixture by anatomically modern humans into Neandertals -if it needs explanation at all. He also takes at face value the Neandertal-modern split time, which is an overestimate under Scenario 4, given that West Africans are used as a proxy for modern humans to estimate that split.<br /><br />Note that the authors can only really reject modern admixture into Neandertals, if they make the assumption that the non-Africans that admixed with them were already closer to Yoruba than to San. However, there is no clear reason to think that for early anatomically modern sapiens.<br /><br />In conclusion, the recent coalescence dates can be easily explained by admixture from moderns into Neandertals <i>before</i> or shortly after the Yoruba-San split.Dienekeshttps://www.blogger.com/profile/02082684850093948970noreply@blogger.comtag:blogger.com,1999:blog-7785493.post-60422182165260370092010-05-09T15:23:41.734+03:002010-05-09T15:23:41.734+03:00I myself would be very suspicious of someone who c...<i>I myself would be very suspicious of someone who clings strongly to a need to classify people based on skin color and facial features. Maybe we should start to put people who do that in a sub-race category: the weak self-esteem, need to obsessively classify sub-race, inflated ego category. <br /><br />Let's get the geneticists working on finding that gene, right away. I'm sure we could form a sub-race out of all the people who have that gene and therefore a compulsive need to classify people based on a narrow set of observable "looks". (and subsequently elevate themselves.)</i><br /><br />Those who know me know that I have no interest in any ego or nos thing. In fact, I have a strong tendency to think independent of myself and my personal and social connections (including biological ones). Racial classification of people is not a simple matter of looks, it goes deep into biology, hence genetics. Genetic study after study after study after study after study after study after study after study after... have confirmed the reality of biological human races, also confirming the results of anthropometric (including craniometry) studies, which have been being made since much earlier than the age of genetic studies.Onur Dincerhttps://www.blogger.com/profile/05041378853428912894noreply@blogger.comtag:blogger.com,1999:blog-7785493.post-29829836618584990692010-05-09T14:46:31.660+03:002010-05-09T14:46:31.660+03:00A new article from John Hawks, which opposes the a...A new article from John Hawks, which opposes the argument of no interbreeding between sapiens and neanderthals:<br /><br />http://johnhawks.net/weblog/reviews/neandertals/neandertal_dna/african-population-structure-neandertal-mixture-2010.htmlOnur Dincerhttps://www.blogger.com/profile/05041378853428912894noreply@blogger.comtag:blogger.com,1999:blog-7785493.post-66003170252493225032010-05-09T14:13:09.548+03:002010-05-09T14:13:09.548+03:00@Dienekes:
That's only because of the paramet...@Dienekes:<br /><br />That's only because of the parameters of the MC equations they have chosen to use.<br /><br />But which is the archaeological justification for such a low age guesstimate? <br /><br />None. There's some tentative anthropometric studies but nothing, absolutely nothing, in the cultural/technological aspect. <br /><br />So the situation is:<br /><br />H. ergaster > H. heidlbergensis > Neanderthal<br /><br />H. ergaster > H. rhodesiensis > H. sapiens<br /><br />With a material splinter at the Acheulean difussion period c. 800 Ka - 1 Ma ago. <br /><br />We can have long "coffee discussions" on MC and anthropometric hunches but they are evidence of nothing unless supported by something else. <br /><br />We lack that 'something else'.Majuhttps://www.blogger.com/profile/12369840391933337204noreply@blogger.com