| Mehtakheri toolkit |
That is what a new study has found, albeit on just one date. Based on that they argue that the recent claim by Mellars et al. (see also here) about an extremely late date for the migration out of Africa (OOA) becomes more plausible.
Sheila Mishra et al., Continuity of Microblade Technology in the Indian Subcontinent Since 45 ka: Implications for the Dispersal of Modern Humans. PLoS ONE 2013. Open access → LINK [doi:10.1371/journal.pone.0069280]
However considering the pivotal role played by South Asia in the genetics of Humankind after the OOA it is still impossible that this microlithic industry corresponds with that process, because the migration and successive Eurasian expansion must:
- Have minimal dates of well before 60-55 Ka ago, time when the presence of H. sapiens becomes undeniable from Palestine to SE Asia and Australia.
- Go at least largely through South Asia; because the distribution and basal diversity of mtDNA M and R, as well Y-DNA F demand it without any reasonable alternatives.
The authors themselves acknowledge that the finding is inconclusive in this debate but they choose to lean for a revised Mellars-style interpretation on their own subjectivity.
Their hypothesis is not exactly like Mellars et al. These proposed an extremely late (c. 40-35 Ka BP) OoA, which would imply also extremely late colonization of East Asia and Australasia by Homo sapiens (via South Asia). In order to "explain" the lack East Asian blade-like technologies (necessary for the old professor's ideas about "modern human behavior") they proposed that the Eastern colonization was led by small populations who somehow lost the technology. But well, as I discussed back in the day, the hypothesis does not stand.
Mishra's revised hypothesis is somewhat more coherent (but still very unlikely): she proposes that East Asia and Australia were actually colonized with Middle Paleolithic technology (neither blades nor microblades) in the time demanded by archaeological data and that South Asia instead was not colonized by our species until c. 45,000 BP, possibly because there was some kind of intelligent archaic hominin (Hathnora?), which blocked the expansion of our species initially.
However the hypothesis is still plagued by problems:
- As I said above, any model that dictates that South Asia was not central to the expansion of Homo sapiens in Eurasia and surroundings must be wrong: genetics demand otherwise. A settlement of South Asia that is posterior to that of East Asia, Papua and/or West Eurasia (other than the initial Arabian trailblazers or boaters) simply does not make any sense.
- The African microblade technology is still quite older (70-60 Ka BP) than the South Asian findings and the similitude may well be a mirage or a matter of convergent evolution. Not the only time that people reinvent the same thing separated by time and space: look for example at Neolithic, which was developed at least in four separate regions of the World, maybe more; or look at the Solutrean style of retouch, used in many different Paleolithic cultures separated by time and space (Africa, Europe, America, etc.)
- It would require that Homo sapiens would travel through Altai and all the evidence in this North Asian keystone region, a necessary corridor for transcontinental travel before the domestication of camels (or at the very least horses), indicates that it was inhabited by "archaic" hominids (Neanderthals, H. erectus/Denisovans) until c. 47 Ka BP, when industries related to those of West Asia and Europe show up (at later dates associated to H. sapiens remains).
The facts:
A C14 date was obtained for the site of Mehtakheri (near Barwah, Nimar region, Madhya Pradesh) annotated as: >42,900 BP, > 46,555 calBP, >45,028 - 48,081 (68% CI range for the calBP date). Another C14 date from the same site is much more recent (34,380 ± 991 calBP).
They also obtained five of OSL dates for section 2 ranging from 41.6(±3.3) to 47.0(±4.9) Ka ago. Another date for this unit of 55.5(±5.8) was not used by the authors because it corresponds to an unstudied layer.
Section 3 has older dates (65-78 Ka) but it corresponds to the Middle Paleolithic.
The microlithic industry seems to continue in South Asia until the Iron Age, suggesting that Neolithic and later developments did not substantially alter the demography of the subcontinent.
All this is very informative but the conclusions suggested don't seem to make any sense. It is much more logical to infer that H. sapiens left Africa with an MSA-like Middle Paleolithic toolkit that was not related to the Nubian culture (the dead horse being beaten once and again by both Mellars and Mishra) but to other ill-defined groups of possible South African affinity (as claimed by Petraglia). Insisting on the Nubian techno-complex, when we do not know it reaching beyond Dhofar (i.e. they did not reach the Persian Gulf "oasis", unlike Petraglia's trailblazers or Armitage's Jebel Faya findings) is taking the part for the whole, as if there was not already a much more widespread and diverse African Middle Paleolithic (MSA, Lupenbiense, Aterian) in those times already.
Instead these data may indicate a relation of some sort with West Eurasian Upper Paleolithic and African Late Stone Age, which are of roughly those dates. This tentative relationship does not imply migration but would just need some cultural contact.
It would be interesting to know more about the MP-UP transition in the area around Arabia Peninsula in order to develop better theories on this tripartite interaction between the West Eurasian early UP, the African early LSA and the South Asian early microlithic industry. These very possible cultural interactions fit well within the wet phase of the Mousterian Pluvial (c. 50-30 Ka ago).
Update (Jul 11): "microliths" that are not microliths
I just looked for the first time at the technical issue of what is a microlith (~1 cm long, ~0.5 cm wide) and the published toolkits only seem to have one microlith senso stricto: the J4 point. All the rest have lengths of 2 cm or larger, often 5 cm or more.
The presence of some microlith-sized pieces (usually points) in early UP cultures is almost standard: Emirian, Chatelperronian, Aurignacian and Gravettian all them have occasional "microliths" (measured by size) an in all cases these are points, exactly as happens in Mehtakheri.
So these toolkits seem to have more relationship, if anything, with Western Eurasian early UP ones, which are roughly contemporary (Emirian is the only clearly older one).
Furthermore, archaeologist Millán Mozota sees even similitudes with Mousterian flaking style (see comments):
Being also puzzled because the inventories described suggest a strong blade/bladelet component, instead of microblades.
Update (Jul 11): "microliths" that are not microliths
I just looked for the first time at the technical issue of what is a microlith (~1 cm long, ~0.5 cm wide) and the published toolkits only seem to have one microlith senso stricto: the J4 point. All the rest have lengths of 2 cm or larger, often 5 cm or more.
The presence of some microlith-sized pieces (usually points) in early UP cultures is almost standard: Emirian, Chatelperronian, Aurignacian and Gravettian all them have occasional "microliths" (measured by size) an in all cases these are points, exactly as happens in Mehtakheri.
So these toolkits seem to have more relationship, if anything, with Western Eurasian early UP ones, which are roughly contemporary (Emirian is the only clearly older one).
Furthermore, archaeologist Millán Mozota sees even similitudes with Mousterian flaking style (see comments):
Bladelet flaking is a typical flaking strategy for this blank type (small pebbles). Specially if the raw material itself is of good enough quality.
It has been documented, for high quality quartz on Mousterian sites, like in Grotte Breuil and, if i recall correctly, other sites in that area of the Italian Peninsula.
Being also puzzled because the inventories described suggest a strong blade/bladelet component, instead of microblades.
I think there is some misrepresentation of the Mellars et al. model. They argue that because of the lower sea levels in the relevant time period, future archaeological sites of early modern humans are expected to be found under the sea. The coastlines at the time were reportedly no less than 20-50 kilometers away from current coastlines. This also goes for Arabia, with its submerged sources of freshwater, absolutely vital to any group of humans venturing through Arabia during the dry periods following MIS 5. So Mellars et al. are not discounting the necessary role of South Asia during the early AMH colonization of Eurasia.
ReplyDeleteI also don't think their model is necessarily inconsistent with the genetic evidence. In fact, it is to a large degree influenced by genetic evidence. This new paper is just another redating of microlithic industries in South Asia. More redatings will follow, I'm sure. In Arabia as well.
A model proposing continuity between migrants that left Africa up to 125 kya runs into big problems as well:
1) There is no evidence of a post-Toba continuity of humans tracing back to Arabia's MIS 5 technological complexes. Rather, there is evidence of a Neanderthal presence in West Asia as late as 40-50 kya
2) The early OOA model isn't aligned with dates from genetic evidence, which you question but IMO without convincing arguments
3) AMH fossils, supporting early OOA, are scarce. The only exception, the Skhul/Qafzeh hominins, have some Neanderthal-like features, and are later replaced by full-blown Neanderthals in West Asia. The 46-63 kya specimen from Southeast Asia, a region with an important role in the early colonization of Eurasia (as shown by genetic evidence), fits the period suggested by the late OOA model
Finally, what would be the reason for early MIS 5 migrants to have become widespread all over Eurasia, but without leaving any visible trace outside West Asia, only to be replaced by Neanderthals living in West Asia? The suddenly widespread distribution of microlithic industries, appearing first in Africa at least 70,000 years ago, would then be a simple coincidence. Notwithstanding the genetic evidence also pointing toward more recent dates.
Admittedly, there is a lack of archaeological evidence to flesh out the details of a recent OOA migration. But we now know there are archaeological finds pointing to commonalities between later technological industries in South Asia, West Asia and Africa, in accordance with the rapid colonization of Eurasia shown by genetic evidence. Important archaeological finds similar to this new study will only increase in the coming decades. Along with ancient DNA contributing to increasingly reliable dates for mtDNA lineages.
"... because of the lower sea levels in the relevant time period, future archaeological sites of early modern humans are expected to be found under the sea".
DeleteThat basically implies believing that the people who lived by the coast never ventured inland nor they had relatives who did. Also both periods under debate were pluvial periods, in which humidity was high enough to allow inland settlement in many parts of Arabia, etc. Even today, in a dry period, areas like Dhofar are lush in the monsoon season. It's like conjecturing that, just because much of Ice Age Europe became submerged 10,000 years ago, Lascaux and Altamira would not be there.
"I also don't think their model is necessarily inconsistent with the genetic evidence. In fact, it is to a large degree influenced by genetic evidence".
How? Never mind, I can only imagine that you will wave the "molecular clock" speculations.
"1) There is no evidence of a post-Toba continuity of humans tracing back to Arabia's MIS 5 technological complexes".
There is: Jwalapuram has the same technologies under and above the ash layer.
"Rather, there is evidence of a Neanderthal presence in West Asia as late as 40-50 kya".
Exactly my point: West Asia was colonized after South and East Asia and very clearly after Australia, where the H. sapiens dates pile up in the 60-50 Ka interval.
Genetically also West Eurasians are 99% derived from other Asian trunks and not any independent nor basal African-derived branch. That is the genetic evidence!
"The early OOA model isn't aligned with dates from genetic evidence"...
The "molecular clock" speculations are not evidence. It's like arguing that God exists because of the Bible or whatever. "Molecular clock" estimates systematically seem like half or even less of the real thing: geneticists who use those speculations never bother demonstrating them, just cite some other author, who demonstrated nothing in turn: that's scholasticism, not science.
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Delete"AMH fossils, supporting early OOA, are scarce"...
Sure but not lacking. In any case absence of evidence is not evidence of absence.
"The only exception, the Skhul/Qafzeh hominins"...
What about Zhirendong? Liujiang? And some others with less clear affiliation or dates like Tam Pa Ling or Callao?
"... have some Neanderthal-like features"...
Only one or two of the many specimens have been suggested to have such Neanderthal look. Anyhow, remember that all non-Africans jointly descend from a seed population that was slightly admixed with Neanderthals.
"Finally, what would be the reason for early MIS 5 migrants to have become widespread all over Eurasia, but without leaving any visible trace outside West Asia, only to be replaced by Neanderthals living in West Asia?"
I don't understand: Neanderthals and Sapiens essentially avoided each other in their respective and almost synchronous expansions. Neanderthals were not just very smart but also terribly strong. Our ancestors initially avoided them, it seems very obvious (notwithstanding occasional contact).
"Admittedly, there is a lack of archaeological evidence to flesh out the details of a recent OOA migration".
Crucially there's a lot of evidence against it. You don't get a hypothesis pass through being proven wrong: that would not be science.
"Along with ancient DNA contributing to increasingly reliable dates for mtDNA lineages".
You wish. I already discussed that issue: aDNA can only help to provide reliable dates if you use all the evidence (for example not ignoring the certain mtDNA H and H6 in Magdalenian Iberia or the likely mtDNA H17'27 in Sunghir, etc.) Manipulating and cherry-picking the data to fit one's preconceptions is not science but what creationists do.
There is: Jwalapuram has the same technologies under and above the ash layer.
ReplyDeleteThe original author has since changed his mind, and believes they were made by archaic humans. Besides, I specifically referred to technologies with links to the earlier Arabian MIS 5 complexes.
I find it odd that you insist on a result that has been abandoned by the original author, but so easily dismiss that microlithic industries distributed from South Africa to South Asia were accompanied by any gene flow.
The "molecular clock" speculations are not evidence. It's like arguing that God exists because of the Bible or whatever. "Molecular clock" estimates systematically seem like half or even less of the real thing: geneticists who use those speculations never bother demonstrating them, just cite some other author, who demonstrated nothing in turn: that's scholasticism, not science.
So when scientists dig up and sequence 10 securely dated ancient humans, check their amassed mtDNA mutations, and compare them to modern samples to reach the most reliable molecular clock ever determined, somehow this is not science?
In reality, you don't seem to have a problem with the concept of a molecular clock. Only when it points to more recent dates than you'd prefer. You freely invent dates that align with your preconceived notions about human origins, but reject the more recent dates which modern science is converging upon. You then go on to lecture others on how to do science.
What about Zhirendong? Liujiang? And some others with less clear affiliation or dates like Tam Pa Ling or Callao?
The date of Liujiang has not been determined, and the classification status of Zhirendong and Callao remains uncertain. Tam Pa Ling is definitely AMH and has been securely dated to 46-63 kya, which is within the range of the recent OOA model. It may seem "early" because Laos is so far from Africa, but we know from genetic evidence that there was a rapid colonization of the southern Eurasian coasts, with modern Southeast Asians carrying a great deal of genetic diversity despite their remote location.
You wish. I already discussed that issue: aDNA can only help to provide reliable dates if you use all the evidence (for example not ignoring the certain mtDNA H and H6 in Magdalenian Iberia or the likely mtDNA H17'27 in Sunghir, etc.) Manipulating and cherry-picking the data to fit one's preconceptions is not science but what creationists do.
Do you question the crucial role of ancient DNA samples in definitively determining the origin and age of haplogroups? I hope you realize that this will be a done issue in some years time, when the ancient DNA record is more extensive. mtDNA H in Magdalenian Iberia is well within the dates reported by Fu et al., based on the dates I find for the Magdalenian on Wikipedia. I am unable to find an academic reference for the mtDNA H17'27 you mention.
Keep in mind that older studies of ancient DNA in particular are often riddled with errors. So, in fact, taking into account all minor anomalies could be considered "cherry-picking" in a sense.
"The original author has since changed his mind, and believes they were made by archaic humans".
DeleteThat's not true. When discussing Mellar's claim I also included opinions from Petraglia taken from the media:
... Professor Michael Petraglia, an archaeologist from the University of Oxford disputes Richards' and Mellars' argument.
Petraglia says there's not enough evidence to rule out an earlier colonisation before the eruption of Mount Toba.
"The research reported by Mellars and colleagues is riddled with problems," he says.
Petraglia says that the similarity between tools used in Africa 60,000 years ago and those from Asia dating to around 35,000 years ago is not a consequence of direct migration.
"These toolkits are separated in time by more than 20,000 years and distances exceeding several thousand miles."
He questions the evidence supporting a migration along the coast. He says that surveys of ancient shorelines have not revealed any evidence for human settlements anywhere along the Indian Ocean shore between 55,000 and 50,000 years ago.
He also says genetic dating should be treated cautiously.
"Most geneticists will admit that genetic dating of the out-of-Africa event is tenuous, at best. Published genetic ages for out-of-Africa range anywhere between 45,000 to 130,000 years ago.
Petraglia says his team is currently conducting archaeological fieldwork in Arabia, India and Sri Lanka they expect will show that the story of human dispersal from Africa is complex.
"What we can agree on is that little research in these key geographic regions has been conducted and much more evidence needs to be collected to support or refute the different theories," says Petraglia.
So essentially Petraglia and I are in the same line.
Delete"So when scientists dig up and sequence 10 securely dated ancient humans, check their amassed mtDNA mutations, and compare them to modern samples to reach the most reliable molecular clock ever determined, somehow this is not science?"
As I discussed HERE and HERE, it is cherry-picking the evidence in such a blatant manner that I feel that Science, the scientific method is being seriously assaulted by dogmatic ideologues with a diploma. In the best case, the only in which I can imagine no ill intent, it would have to be an explosive cocktail of ignorance, arrogance and poor intellectual capabilities. Seriously...
"In reality, you don't seem to have a problem with the concept of a molecular clock".
I do have a BIG problem with it being presented as "evidence" or "facts" and not the more or less educated hunch it is. When C-14 was presented in society, in times more rigorous than ours, it seems, the proponents had to demonstrate it first of all, not once but several times. As the method proved reasonably reliable in all independent replications, it was accepted. Nowadays it seems it's enough to cross-dress a hunch with some obtuse equations to be presented as "scientific fact". What's next? The Dark Ages?!
The idea as such is not as bad but the results so far have failed to make any sense. And that is because of systematic errors reproduced by scholastic inertia by people who are more ready to believe some equations fed on assumptions (such as the most unlikely Pan-Homo divergence dates) than the repeated evidence of their results being wrong again and again and again...
With such ill-built dogmatic "science" no plane would ever fly, no rocket would ever reach out to the stars and this conversation would not be taking place.
"The date of Liujiang has not been determined, and the classification status of Zhirendong and Callao remains uncertain".
Burning nails.
Actually Zhirendong is very clearly an H. sapiens: every amateur anthropologist would quickly notice it has a chin, something neither Neanderthals nor H. erectus had (and that's why they were so prognathous and yet their bite was not as efficient as ours). Liujiang's date is as good as it can be. Callao is indeed ambiguous, yes.
But even accepting your "burning nails" we still have clear evidence of H. sapiens in Australia by at least 55 Ka ago, probably more like 60 or 60-something, and zero evidence of any Siberian journey for our species before 47 Ka ago (but lots of evidence of H. erectus, Neanderthals and their likely "Denisovan" hybrid. So they had no alternative but to go via South Asia.
Genetics, not "molecular clocks" but the phylogeny also demands that the went via South Asia. Nothing within Y-DNA F, mtDNA M or R can be explained without South Asia being at the origin. And that's the vast majority of non-African lineages.
It's not just SE Asia or Australia but Europe! How can the (ydna) F- and (mtdna) R-derived European majority lineages be here without first being in South Asia?! And if H. sapiens arrived first to Europe c. 49 Ka BP (related to Palestine c. 55 Ka BP or earlier), a 48 Ka arrival to South Asia is totally insatisfactory. It's not about any "clock" but the much more basic concept of first and second, before and after. Before it MUST be South Asia, Europe must be AFTER.
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Delete"Tam Pa Ling is definitely AMH and has been securely dated to 46-63 kya, which is within the range of the recent OOA model".
Barely so. 63 Ka is clearly older than the Mousterian Pluvial scenario speculated here. So would be 50 Ka ago as well: most of the Tam Pa Ling range is out of this model. But its full range is within the older OoA scenarios within the Abassia Pluvial.
"Do you question the crucial role of ancient DNA samples in definitively determining the origin and age of haplogroups?"
What I question is not using the actual DNA samples available. Fu and Brotherton used just some arbitrarily cherry-picked data, what is a scandal!
In any case they can only provide minimum dates. For example we know (not thanks to Brotherton's manipulation, nope!) that H6 existed in Magdalenian times but we do not know when it was born.
Whatever happens with the "molecular clock" in mtDNA it is clear that it is not regular: some branches are much larger/shorter than others and no theory nor correction has been put forward (except my own AFAIK) in order to correct for that: if, counting from a hypothetical ancestral node A (not the actual haplogroup A), branch A1 accumulated 5 mutations to present time and branch A2 has 15, it is obvious that on average each A1 mutation accumulated in 1/3 of the time that each A2 mutation did. And this is not just theoretical case but happens in the actual phylogeny, even if maybe a bit less exaggerated than I presented it. It happens when we compare R0 and U, when we compare M and N... Ironically it is the branches showing large star-like structures the ones that accumulate less mutations. Why? IMO because novel lineages were drifted out, by mere statistical reason, much more frequently than among smaller populations. So, in a sense, large star-like haplogroups were "frozen in time".
And you can't count frozen time because it was the molecular clock itself was frozen.
"mtDNA H in Magdalenian Iberia is well within the dates reported by Fu et al."
He didn't even bother explaining how he reached those dates and it would anyhow imply an Iberian origin for H, which is extremely unlikely. Magdalenian mtDNA H6 is certainly not within the ranges of Brotherton's dedicated study (pamphlet) and he actually infers his dates from a mis-estimate of H6 age (among other reference points).
It's not the first time I discuss this so please read in depth what I said back in the day (links in my earlier comment). I recalibrated Brotherton's estimates with Hervella's H6 find (surely H6a* or H6a1, because there's no other H6 in this part of Europe, being H6b and H6c exclusive of Eastern Europe) and the result for H was much more radical: Aurignacian times or earlier very plausible, Solutrean age minimum.
And that makes all sense with such a huge star-like structure as H has, a clear signature of a very fast and almost unresisted expansion, exactly as is the case with M. Only these two nodes are so huge in all the human phylogenetic tree, a clear signature of no meaningful resistance to expansion. M and H are most likely pioneers (or else unlikely intense re-colonizers).
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Delete"I am unable to find an academic reference for the mtDNA H17'27 you mention."
http://soilinst.msu.ru/~ladygin/sungir/dna/index.php
We successfully amplified the fragments of mtDNA HVSI of individuals S2 and S3. This indicates the excellent preservation of SUNGHIR bone remains. The results of our preliminary analysis showed the nucleotide sequences of mtDNA HVSI for the two buried SUNGHIR adolescents are identical. Their sequence is a derivative of so-called "Cambridge" mtDNA sequence, differing from it probably only in one position (G-A transversion in position 16129).
Back in the day I could only find one fit: H17'27 (or some descendants within the H17 branch). Right now I'm a bit confused by the change of notation in PhyloTree however but I believe that the conclusion stands. It's not 100% proven but it is quite likely and can't be ignored by the meticulous researcher.
Those "microblades" on the figure look like a bit as a "hodgepodge", they are not very similar to what I understand as UP microlithism. And i think they could not be associated with African microliths, neither. Not typologically, nor tecnologically.
ReplyDeleteThey seem to be (predominantely) chalcedony: bladelets, ellongated flakes, and cores, flaked from small quartz pebbles. Bladelet flaking is a typical flaking strategy for this blank type (small pebbles). Specially if the raw material itself is of good enough quality.
It has been documented, for high quality quartz on Mousterian sites, like in Grotte Breuil and, if i recall correctly, other sites in that area of the Italian Peninsula.
On the other hand, the other figure and the inventories described on the paper they suggest a strong blade/bladelet component...
So, I really would like to see the rest of the assemblages from Indian site, before accepting the "pan afroeurasian microlithism" as a valid proxy for this case.
Sorry, on second paragraph i meant "small chalcedony pebbles", not small quartz pebbles
DeleteNow that someone goes to the technical matter, I just noticed that the (smallest) pieces are almost never smaller than 2cm and often of 5cm or more. I can find Aurignacian points in my local museum that small and nobody speaks of microlithism (although for the amateur they do strike as surprisingly small and delicate).
DeleteIn fact per the first reference at hand (Wikipedia, sure) the "standard" microlith is defined as being of about 1cm long and 0.5cm wide and a number of artifacts from "non-microlithic" cultures (such as Emirian, Chatelperronian, Aurignacian, Gravettian, etc.) are close to this definition.
Looking now at the published toolkits and paying more attention to the scale, only one piece can be considered a microlith: J4. The next ones in size (D78, G5, C26) are already at 2 cm in length, what is not microlithic, right?
It seems to me rather a "regular" blade industry. Also these tools do not look at all like the typical geometric microliths (trapezoids specially) shown by Mellars in the impacting image (but dated to c. 35 Ka BP in India; >60 Ka BP in Africa, it seems). If so, we are looking not at direct (and unattested) African influences but at some sort of interaction with West and Central Asia.
And that makes much better sense, IMO.
I made an update based on what you and I said here, Millán, because I feel it is very important.
DeleteI quoted some of your words with due credit. If you have any issue with that or want to make some precision to your remarks or my own, please tell me.
At least for haplogroups within R, Fu et al. analyzed some highly useful samples. 2 Dolni Vestonice samples that are slightly older than 30,000 years belong to U, but have two mutations in common with U5, which is estimated to have diverged less than 30 kya according to this study. Also, the Tianyuan specimen lived about 40 kya and is basal to modern B4'5 samples, which fits with conventional mtDNA age estimates (Wikipedia lists 50 kya for B4'5). Meaning he shouldn't be all that far removed from the R root, either.
ReplyDeleteSo based on the ancient DNA samples available in this time range, the conventional molecular clock appears to hold up. Proposing that the overall mutation rate should be slowed to half or even less would have highly significant implications. It would impact the expansion of haplogroups related to the modern human settlement of regions like Australia, Europe and the Americas, leading to some pretty unbelievable dates. Not to mention it wouldn't fit with the sequences mentioned above.
If you would like to argue for some distinct evolution of mtDNA H in particular, then you're free to do so. If your speculations turn out to be true, then you will be redeemed by future ancient DNA studies. I just don't see how the genetic data is in your favor right now, so the animosity toward published research on mtDNA mutation rates is unwarranted IMO. Data should be the center of our attention. Any potential "agenda" among authors is of no long-term significance, since the origin of haplogroups will be resolved conclusively with the advent of ancient DNA. There is already Brotherton's study which attempted to calibrate the mutation rate specifically with ancient mtDNA H genomes in mind, but that was just the tip of the iceberg.
BTW, have you taken a look at this page? It calls into question the sequences you mentioned being reported as H and H6.
It doesn't matter anymore: clear archaeological evidence of Africa-rooted H. sapiens toolkits have been found by now in India dated to ~96,000 BP. Check mate to Mellars and Mishra and a whole decade of confusing "molecular clock" speculations.
DeleteIt can be said louder but not clearer.
"Fu et al. analyzed some highly useful samples."
Neither he nor Brotherton considered all the available evidence. Fu's paper is also extremely confusing: I read it several times and could only conclude that it was not written to be understood but to make some arbitrary claims. Brotherton's paper is much better in that but it still ignores key evidence.
I have no meaningful problems with Fu's age estimates for U (although some details also seem to be inconsistent: U5 should be younger than U2'3'4'7'8'9, not older) but all the rest seems not based on anything.
"Also, the Tianyuan specimen lived about 40 kya and is basal to modern B4'5 samples... Meaning he shouldn't be all that far removed from the R root, either".
Basal does not mean ancestral but that it is a seemingly extinct branch derived from that B4'5 node. It clearly indicates that R must be older than 40 Ka, something I agree with, but it does not say much more.
In the end it's the same for all aDNA: they give minimum ages but can't give exact ages on their own. I just made an update to my Spanish-language article on the Eurasian expansion of H. sapiens from the viewpoint of genetics and the rough dates I get from archaeological calibration imply that the age of R may be of around 66 Ka BP (several, say 8, millennia up down as CI). It should be older than the development of UP cultures in West Asia, which has a minimal date of c. 55 Ka BP (Emirian).
Basically we must use that Emirian date and the Katoati date of ~96 Ka (or the Zhirendog one of ~100 Ka) in order to estimate the earliest dates of Eurasian (and African if you wish) L3 sublineages.
"... you will be redeemed by future ancient DNA studies."
I am "redeemed" or rather vindicated so often that I fear I risk becoming a bit arrogant. But at risk of that, I must say that I have little doubt that present and future aDNA studies are and will be quite coherent with what I say.
"BTW, have you taken a look at this page? It calls into question the sequences you mentioned being reported as H and H6".
I know that Jean Manco says that and I also know that she has absolutely no grounds for what she says. I used to collaborate with her, I used to email with her but we fell out on this issue precisely: I was transmitting her all the weight of the evidence, translating the emails I bothered obtaining with explanations from the researchers but she just wouldn't listen. I suspect that she was so persuaded of her own interpretation, had so much invested on her hypothesis (incl. a book to be published around those dates) that she preferred to ignore the facts.
Very sad. I know for a fact that I am not the only person angry or disappointed at her for her betrayal of truth, facts, science, just to put all her personal weight in favor of her pet hypothesis.
Very sad, really.
I have a set of these that are ancient .I found them .havent had them looked at yet
ReplyDelete