Wednesday, January 28, 2015

'Smoking gun' found for the Out of Africa Theory

An Israeli anthropologist, Israel Hershkovitz, claims that he and his team have found the archaeological smoking gun for the Out of Africa theory, a theory which has been genetically reinforced for the past couple of decades,
"This is the smoking gun that confirms what geneticists have been predicting," he said. "We had finds from Africa and from Europe but we were missing the connection between them; it's like finishing a puzzle and finding that a piece is missing: it drives you crazy. This is the missing connection between the older African populations and the later European populations."
The evidence, a 55,000 year old partial skull found in a cave called Manot in Northern Israel, also disqualifies the popular Bab-el-mandeb route that modern humans may have took as they were leaving Africa, and strengthens a Nile valley route according to the same Anthropologist,
Hershkovitz told Haaretz that the presence of modern humans at Manot also supports the idea that Homo sapiens sapiens left Africa through the Nile valley, Sinai and what is today known as Israel,
http://www.haaretz.com/life/archaeology/1.639350

Obviously, a scenario of multiple exits out of Africa, first via Bab-el-mandeb and then via the Nile valley, can not be necessarily discounted by this find.

Levantine cranium from Manot Cave (Israel) foreshadows the first European modern humans

A key event in human evolution is the expansion of modern humans of African origin across Eurasia between 60 and 40 thousand years (kyr) before present (bp), replacing all other forms of hominins1. Owing to the scarcity of human fossils from this period, these ancestors of all present-day non-African modern populations remain largely enigmatic. Here we describe a partial calvaria, recently discovered at Manot Cave (Western Galilee, Israel) and dated to 54.7 ± 5.5 kyr bp (arithmetic mean ± 2 standard deviations) by uranium–thorium dating, that sheds light on this crucial event. The overall shape and discrete morphological features of the Manot 1 calvaria demonstrate that this partial skull is unequivocally modern. It is similar in shape to recent African skulls as well as to European skulls from the Upper Palaeolithic period, but different from most other early anatomically modern humans in the Levant. This suggests that the Manot people could be closely related to the first modern humans who later successfully colonized Europe. Thus, the anatomical features used to support the ‘assimilation model’ in Europe might not have been inherited from European Neanderthals, but rather from earlier Levantine populations. Moreover, at present, Manot 1 is the only modern human specimen to provide evidence that during the Middle to Upper Palaeolithic interface, both modern humans and Neanderthals contemporaneously inhabited the southern Levant, close in time to the likely interbreeding event with Neanderthals2, 3.

Link ( Closed Access) 

19 comments:

  1. The Bab el Mandeb exit has never made the slightest but of sense to me. It has always looked as though humans did not develop boating technology any where near the Mediterranean until almost the Neolithic although humans had obviously reached Austraiia by boat long before that.

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    1. The idea is that sea levels were much lower back then and that the 12 mile width of the Red Sea at the strait today, would have been much narrower, with some islands possibly existing in between and making it possible for early beachcombing humans to traverse the hypothesized southern route.

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  2. Yes, but tidal movement would have made crossing the strait hazardous at least. And there is actually no evidence for any crossing until we find evidence for trade up and down the Red Sea. I agree 100% with the comment, 'The evidence, a 55,000 year old partial skull found in a cave called Manot in Northern Israel, also disqualifies the popular Bab-el-mandeb route that modern humans may have took as they were leaving Africa, and strengthens a Nile valley route according to the same Anthropologist', Another factor is that either shore of the Red Sea is today among the most desolate, arid places on earth. Even at times of decreased aridity the more northerly route would be much easier.

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    1. Anyway, this new find can not disqualify multiple migrations out of Africa, like I pointed out and referenced in the blog post, this is something that has previously been postulated but has not been proven archaeologically.
      If all non-Africans are descendents from only one migration however, yes, this find makes the Nile route the more convincing one.

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  3. Yes, the Red Sea crossing 'is something that has previously been postulated but has not been proven archaeologically'. In fact it was postulated when the great southern coastal migration had been invented as an attempt to explain the very early presence of humans in Australia, trying to make it tie in with a fully-formed Upper Paleolithic from Africa. We now know such an explanation was unnecessary, I find it difficult to see all non-Africans as being other than a single exit, especially the Y-DNA. Two mt-DNAs may have come out, but the two may have come out together. Inbreeding was avoided by a period of admixture with groups already outside Africa such as Neanderthal and Denisovans. I'm sure time will tell they are not the only earlier leavers who form part of the modern human mixture.

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  4. Speculatively, YDNA DE and mtDNA M (or pre-M) could have gone the southern route across the bab-el-mandeb, later giving birth to YDNA D in the Southern parts of Asia. Separately, YDNA CF and mtDNA N (or pre-N) could have gone the northern route via the nile valley, later giving births to YDNA C and F. Descendants of C and F could have then mingled back with the southern route exodus in and around the south Asian area and continued the moved to Oceania and so forth.

    I admit however such a scenario would create a few holes, like the initial migrations would have to have been temporally quite close, mismatch in expected YDNA variance patterns, etc....

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  5. Possible. But to say, 'giving birth to YDNA D in the Southern parts of Asia' is incorrect. D is virtually unknown in India, and where present is closely associated with Tibeto-Burman speakers and so is almost certainly a relatively recent arrival. Apart from D in the Philippines and the Andamans the haplogroup's main branches are in Tibet and even further north. I agree M tends to be southern but is more likely associated there originally with Y-DNA F haplogroups. And it is certainly not necessary to postulate a Bab-el-Mandeb exit for it. I agree Y-DNA C probably took a northern route and later was eliminated from Central Asia by climatic cooling until eastern branches were once more able to expand. Mt-DNA N is in the same situation as far as I can see. That explains the apparent separation of eastern and western branches of mt-DNA N.

    I think the fact that the big early split in Y-DNA lines is the B/CT one, the two lines are completely separate, and obviously isolated from each other. To me this obviously represents a split between African and Eurasian branches of the BT haplotype. There is nothing in the subsequent splits so convincing. Even the D/E split postdates that divergence and is quite close to the C/F split as well. E is therefore most likely the product of back migration of either DE or E itself. Most likely the former I suspect.

    "I admit however such a scenario would create a few holes, like the initial migrations would have to have been temporally quite close, mismatch in expected YDNA variance patterns, etc...."

    Too many holes I think.

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  6. By the way, my study of haplogroup distribution started with Polynesian haplogroups and their origin. In other words instead of starting in the middle I started on the edge, just as you would when unravelling a woollen garment. The main mt-DNA in Polynesia is B4a1a1a with its origin in Taiwan and the Philippines. The main Y-DNA is C1b2a1 (new nomenclature) with its origin in Southern Wallacea. Minor other haplogroups in Polynesia have an origin in Melanesia. These were presumably picked up along the route.

    But from that start it is then possible to unpick the various haplogroup movements right back to Africa. I admit there are still some holes.

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  7. “But to say, 'giving birth to YDNA D in the Southern parts of Asia' is incorrect. D is virtually unknown in India, and where present is closely associated with Tibeto-Burman speakers and so is almost certainly a relatively recent arrival.”

    'Southern parts of Asia' is not limited to India, I was more specifically referring to the basal D* lineages found in the remote islands of the Indian Ocean, the Andamans. Although it is true that D-M174 is mostly found at higher frequencies in mainland East Asia, it is so fragmented that the frequencies alone don't tell us much about where it could have possibly originated. D-M174 is basically found in appreciable amounts (>5%) in only 3 areas; Tibet, Japan and Andaman Islands (Shi (2008)), where the Japanese variants of D-M174 were found to be the youngest. I estimate DE-M145 to be ~ 60 KYA and D-M174 to be ~ 43 KYA, using Hallast (2014) but adjusting for Fu (2014)'s Fossil-calibrated rate.

    “I agree M tends to be southern but is more likely associated there originally with Y-DNA F haplogroups.”

    Why is it more likely?

    “E is therefore most likely the product of back migration of either DE or E itself. Most likely the former I suspect.”

    If DE is ~60 KYA, and there is no archaeological sign of modern humans outside of Africa before 55 KYA, as exemplified by the very subject of this blog post, then I don't see any reason for why one would infer DE as a 'back-migration' into Africa, unless (a) the people who back-migrated did so either in totality without leaving any descendants outside Africa, unlikely, or (b) the people later became a dead end population outside of Africa, or (c) Archaeological evidence of continuous modern human populations (that fits with the age of DE) outside of Africa is to be discovered at some future time, which certainly does not provide a credible basis for making such an inference today.

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  8. "I was more specifically referring to the basal D* lineages found in the remote islands of the Indian Ocean, the Andamans".

    That 'D' is unlikely to be 'basal'. Human presence on the Andamans is probably no earlier than 30,000 years, and probably even more recent. Besides which Andaman D is unlikely to be other than a single haplogroup. Although a new 'D2' has been identified in the Phillipines that too is likely to be a relatively recent arrival. More work needs to be done on Andaman Y-DNA D to see where exactly it lies.

    "Why is it more likely? [associated there originally with Y-DNA F haplogroups]"

    Because, like Y-DNA F, mt-DNA M appears to be primarily a South Asian haplogroup whereas N is almost unknown in that region (apart from various R-derived haplogroups).

    " (a) the people who back-migrated did so either in totality without leaving any descendants outside Africa, unlikely"

    I think that scenario is very likely. It would have been DE rather than E that back migrated, developing into two geographically divergent branches, D and E. Ultimately it will depend on whether of not anyone can extract DNA from the Manot fossil.

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  9. "Why is it more likely? [associated there originally with Y-DNA F haplogroups]"

    In the context of this conversation, the question was, 'why is mtDNA haplogroup M more likely to be associated with YDNA haplogroup F than it is with YDNA haplgroup D'. The answer is that its not more likely, at best it is equally as likely, as some of the most frequent areas of mtDNA haplogroup M in Asia; Tibet, Japan and the Andamans, happen to also be the most frequent areas where YDNA haplogroup D exists.

    " It would have been DE rather than E that back migrated, developing into two geographically divergent branches, D and E. Ultimately it will depend on whether of not anyone can extract DNA from the Manot fossil."

    With our current knowledge of haplogroup E's distribution and phylogeny, there really is no sustainable position to hold that argues for the E-M96 mutation occurring outside of Africa, so its just a waste of time to even engage with such a debate.

    However, with respect to haplogroup DE, due to the paucity of DE(X D,E), in addition to the globally distant occurrence of its children branches, D and E, there is a possibility that the mutation could have occurred outside of Africa, but when you examine the fact that there were likely no modern Humans outside of Africa at the time the mutation that defined Haplogroup DE occurred, then the probability of that possibility shrinks significantly.

    To claim that any haplogroup is a back-migrant to Africa, it seems to me that the very first thing one would have to prove is if there even were any modern humans to transport the mutation back into Africa. For example, we know that by the time the J-M304 and R-M207 mutations occurred in the Y-chromosome, there is archaeological evidence of modern humans living outside of Africa, so then we can proceed to phylogenetic/frequency/variance analysis on how possible back-migration scenarios may have played out to explain the occurrence of those mutations in Africa, without the prerequisite evidence of those modern humans existing however, nothing but empty theories can proceed.

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  10. "'why is mtDNA haplogroup M more likely to be associated with YDNA haplogroup F than it is with YDNA haplgroup D. The answer is that its not more likely, at best it is equally as likely"

    I don't think so. Y-DNA F seems unequivocally to have moved east through South Asia. With no accompanying mt-DNA? Unlikely, As things stand M diversifies hugely in a star like pattern. To me that is unlikely to be so but if it is accepted than M is most likely to have expanded from somewhere near the China/Burma/India border region. But how did it get there from Africa? Interestingly M1'20'51 stretches in a thin band through Eurasia from North Africa to Laos. Is the haplogroup in fact basal to the whole clade? Possibly. Although there looks to have been a major expansion from the China/Burma/India border region a group of M haplogroups is restricted to South Asia and shows no connection with the other region. This includes the hugely diversified clade M4''67.

    "some of the most frequent areas of mtDNA haplogroup M in Asia; Tibet, Japan and the Andamans, happen to also be the most frequent areas where YDNA haplogroup D exists".

    All those branches have connections with the China/Burma/India border region and quite likely originated there. And I would place D's origin in much the same region, or perhaps a little further north. To me it is likely that mt-DNA M met up with Y-DNA D as it moved north, possibly originally accompanied by the ancestors of NO or K2a as it is now called. Y-DNA D's presence in the region is to me unlikely to be explained by a similar eastward journey through South Asia. More likely it became isolated in the east after having moved through Central Asia at a climatically appropriate time.

    "With our current knowledge of haplogroup E's distribution and phylogeny, there really is no sustainable position to hold that argues for the E-M96 mutation occurring outside of Africa, so its just a waste of time to even engage with such a debate".

    he statement that 'DE rather than E that back migrated' is entirely compatible with the statement that the E-M96 mutation occurred in Africa. Just as the D-M174 most likely occurred near northeastern Tibet. DE obviously became widespread early in its development.

    "the fact that there were likely no modern Humans outside of Africa at the time the mutation that defined Haplogroup DE occurred"

    That statement is very unlikely to be correct. DE formed from CT which to me almost certainly formed outside Africa. Neither C nor F can realistically be regarded as having formed in Africa. Besides which the date for the first human emergence from Africa keeps being pushed back further and further. It certainly has nothing to do with the first appearance of the Upper Paleolithic

    "we know that by the time the J-M304 and R-M207 mutations occurred in the Y-chromosome, there is archaeological evidence of modern humans living outside of Africa"

    As a matter on interest, what date do you place on DE's formation?

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  11. "As a matter on interest, what date do you place on DE's formation? "

    The most recent published paper with NGS for the Y-chromosome is Hallast (2014), they estimate the DE-M145 node at 48.1KYA, however, they used Xue(2009) pedigree rates, the most accurate mutation rate to date is Fu (2014), which derived its rates from actual ancient DNA (Ust-Ishm), Fu (2014)'s rate is 25% slower than Xue (2009)'s, which means the best estimate for the DE-M145 node is ~60 KYA. CT-M168 is also ~ 60KYA using the same method.

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  12. "the best estimate for the DE-M145 node is ~60 KYA. CT-M168 is also ~ 60KYA using the same method."

    With humans having arrived in Australia by 50,000 years ago that date is quite believable. But that does place modern humans outside Africa by 60,000 years ago.

    "we know that by the time the J-M304 and R-M207 mutations occurred in the Y-chromosome, there is archaeological evidence of modern humans living outside of Africa",

    We know modern humans must have been outside Africa long before those mutations took place though. K2a-M214 must have formed, and definitely outside Africa, longer than 45,000 years ago because the Ust'-Ishm individual had that mutation. K2a probably formed roughly contemporary with K2b-M331, the ancestor of R-M207, also definitely well outside Africa . That places modern humans well outside Africa by at least 45,000 years ago and presumably much earlier than that.

    "when you examine the fact that there were likely no modern Humans outside of Africa at the time the mutation that defined Haplogroup DE occurred, then the probability of that possibility shrinks significantly".

    Indicating that CT was the earliest modern human haplogroup outside Africa, Some time around 60,000 years ago.

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  13. Regarding mt-DNA M. Some time ago I compiled this list of where the various subgroups have been found. You may find it relevant to the spread of the haplogroup and that of Y-DNA F:

    http://ourorigins.wikia.com/wiki/Mt_M_west_to_east

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  14. " But that does place modern humans outside Africa by 60,000 years ago. "

    No, it doesn't, what places modern humans outside of Africa by 60KYA is when archaeologists find AMH outside of Africa on or before 60KYA, so far AMH has only been found @ 55 KYA (Subject of this blog post), all other AMH and behaviourally AMH related finds outside of Africa post-date 55 KYA, fact!

    " That places modern humans well outside Africa by at least 45,000 years ago and presumably much earlier than that. "

    Using the same method I outlined above, K-M9 node is estimated at 36 - 47 KYA, since we know that Ust-ishm belonged to K(xLT), we can also constrain the K-M9 mutation to have occurred by at least 45 KYA, which means that the calculation would be correct at the upper portion of the range, similarly DE has a range of 53 - 69 KYA, again if we assume that the upper end of that range is correct then that would place the DE-M145 mutation at ~69 KYA, again this is even further removed from 55 KYA which is when the earliest AMH has been found outside of Africa, giving us no reason to believe that the mutation occurred outside of Africa.

    "Indicating that CT was the earliest modern human haplogroup outside Africa, Some time around 60,000 years ago. "

    Of course it was, all non-Africans and a majority of Africans belong to CT to this day, that does not mean the mutation itself, CT-M168, occurred outside of Africa as you are trying to imply.

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  15. "so far AMH has only been found @ 55 KYA (Subject of this blog post), all other AMH and behaviourally AMH related finds outside of Africa post-date 55 KYA, fact!"

    That would mean an almost instant arrival in Australia, something I find difficult to believe. We also have other human remains that appear to be at least moving towards 'modernity' in modern Israel that are much older than 55,000 years. They are yet to be tested.

    "since we know that Ust-ishm belonged to K(xLT), we can also constrain the K-M9 mutation to have occurred by at least 45 KYA,"

    Probably quite some time before that. Ust'-Ishm, at 45,000 years, is actually K2a(xNO), and so that is one step more than just K-M9. I presume you accept CF as having formed outside Africa. From CF, therefore, we have F, then IJK, then K, then K2, then K2a. That's quite a list of mutations from a mere 10,000 years.

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  16. "That would mean an almost instant arrival in Australia, something I find difficult to believe."

    It's only ~1.6 miles per year, in other words if each generation moved an average of ~50 miles starting from the Levant @ 55 KYA, they would reach Australia by 50 KYA, seems very doable even to a city dweller like myself, let alone some rough-necked hunter gatherers.

    "We also have other human remains that appear to be at least moving towards 'modernity' in modern Israel that are much older than 55,000 years. They are yet to be tested."

    Don't believe Dienekes' hype! Those Skhul and Qafzeh remains are thought of as dead end populations by most professionals, allow me:

    The clear implication of these finds is that, whilst the human populations represented at Skhul and Qafzeh were essentially modern in both anatomical terms and in terms of clearly symbolic behavioral patterns, the levels of technology associated with these populations were still of strictly archaic, Middle Palaeolithic form (71, 72). Viewed in these terms, it is equally interesting that the early incursion of these anatomically modern populations into southwest Asia seems to have been a very localized and short-lived event, apparently confined to this southwest Asian region, and followed by a reestablishment of the earlier Neanderthal populations within these regions from at least 70,000 B.P. onwards, as reflected by the typically Neanderthal remains recovered from the later Mousterian levels at the Kebara cave, Tabun, Amud and Shanidar (1, 71, 72, 78). In other words, it would seem that whatever the intellectual and symbolic capacities of these early anatomically modern populations, their levels of technological and socioeconomic organization were not sufficient to withstand competition from the long-established Neanderthal populations of Eurasia during the later (and colder) stages of the Middle Palaeolithic sequence (71, 72, 78).

    www.pnas.org/cgi/doi/10.1073/pnas.0510792103

    "Probably quite some time before that. Ust'-Ishm, at 45,000 years, is actually K2a(xNO), and so that is one step more than just K-M9."

    It depends how the average branch length below the K2a node and that between the K-M9 and K2a node compare with each other, if they are similar or only slightly different then the time difference would also be negligible. Example, using Hallast (2014) the time between CT-M168 and DE-M145 is very close even-though the latter is phylogenetically one step lower than the former.

    " I presume you accept CF as having formed outside Africa."

    I am agnostic about it, looking at it's 'children' SNPs, it looks like it formed outside Africa, looking at it's 'parent' and 'sibling' SNPs however, not so much. A Basal CF find, i.e. CF (X C,F), would tilt my opinion accordingly. If I were to wager on the Y-DNA of this Manot find, I would place my bets somewhere below CT-M168 and above CF-P143.

    " From CF, therefore, we have F, then IJK, then K, then K2, then K2a. That's quite a list of mutations from a mere 10,000 years."

    It depends on the average branch lengths, see my comment above.

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