Unlike what John Hawks had apparently found a few months ago but similar to what I thought apparent from the original Green et al. data back in 2010.
Mathias Meyer et al., A High-Coverage Genome Sequence from an Archaic Denisovan Individual. Science 2012. Pay per view ··> LINK [doi: 10.1126/science.1224344]
Denisovan ancestry is claimed now to be only found among Aboriginal Australasians (Papuans) but then again the data in the supplementary material (freely accessible) seems, to my untrained eyes, to allow for a thin Denisovan genetic influence in all Eurasia.
I withhold my judgment because there seems to be a lot of sensibility to methodology in this hair-splitting excercise. John Hawks however has written a lengthy article trying to explain why both results appear contradictory regarding which levels of Neanderthal admixture. I would not bet much for his explanation however: I'd rather suspect that the methodology is not sound enough to estimate very thin admixture, so they are getting contradictory results in the uncertainty zone, what is just logical - even if a Schrödingerian kind of logic, of course.
Another finding is that Denisovans were apparently quite endogamous had very low diversity for modern standards, specially in the short bloc zone (ancient bottleneck) but also in the long bloc one (recent endogamy)*.
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*Red text was updated,slashed outtext was removed after first publication.
minor note: not sure endogamy is the right word. they didn't long blocks which indicated inbreeding, as one might expect in endogamous groups. rather, a bottleneck and low long term effec pop. at least in this individual.
ReplyDeleteI'm going to correct that because the precise term is "low diversity". Still she still was very high in the recent endogamy score (longer blocs), only surpassed by the Karitiana. So it's both things but more of the ancient bottleneck one.
DeleteI know that the authors simulate an ancient bottleneck only but I see that the Denisovans stand out in all ROH length segments (with the Karitiana exception). Also they are not so outstanding (like 25% more "only") in the short ROH zone, where they are roughly comparable to many Eurasians and the Mbuti.
Delete"Denisovans ... had very low diversity for modern standards, specially in the short bloc zone (ancient bottleneck) but also in the long bloc one (recent endogamy)".
ReplyDeleteSuch low diversity surely represents a level of inbreeding inconsistent with any real similarity with SE Asian H. erectus. How would you now explain the Denisovan element in the Papuans?
Not inconsistent: the estimated age of the bottleneck is c. 700-500 Ka ago, which is long after the expansion of H. erectus. We do not know if that applies to all H. erectuses, only to one Denisovan.
DeleteI know that the cave had excellent preservation conditions. But still, the ability to get such a high quality genome from an ancient fragment of finger bone is amazing. Assuming technological civilization doesn't succumb to its many woes, the prospect for further advances in genetics is greatly to be anticipated.
ReplyDelete"... the prospect for further advances in genetics is greatly to be anticipated"...
DeleteFor sure: it's a science in its infancy. However I am very concerned about many of the possible applications of this science, like redefining humankind in the line of "Brave New World". It can be a power like no other and, much like nuclear, for the bad almost only in its technological applications.
"We do not know if that applies to all H. erectuses, only to one Denisovan".
ReplyDeleteIt certainly seems to apply the the population this particular Denisovan belonged to. So the Denisovan population is extremely likely to have diverged considerably from SE Asian H. erectus over the period since 700-500 Ka ago.
"the ability to get such a high quality genome from an ancient fragment of finger bone is amazing"
Absolutely.
The generalization to all archaic Asians in the former H. Erectus range from one Denisovian may have some validity when its comes to lack of diversity and effective population size history. But, generalizing from this one (very late for the H. Erectus chronology) individual to the entire hominin species re: endogamy is probably not valid. There is good reason to think that this sample is from a relict population that may have been recently forced into greater inbreeding that had been common in the past due to declining population.
DeleteWhile the current carriers of admixture live in the extreme SE Asia (where one would expect erectus), Denisovans obviously did not. They lived where you'd expect heidelbergensis-like populations, and a reasonable interface of AMHs and Denisovans could have been in southern refugia of the latter and the northernmost initial expansion of the former, during wet times: i.e., northern Afghanistan and Pakistan.
ReplyDeleteA such heavily admixed middle-paleolithic population could have been the prominent human representation south of the Himalayas and reaching into Sahul before being marginalized first by the Toba eruption and culturally modern UP people, and later by neolithic advances.
I don't see any genetic or archaeological signature of any such population replacement or "marginalization" affecting wide areas (i.e. "South of the Himalayas"). On the contrary, I feel that the "Denisovan" (H. erectus) admixture event happened either in Sundaland (where they may have been replacement) or even further away in the islands (cf. H. floresiensis, probably H. erectus).
DeleteWell, but then we really have almost no evidence 100,000ya to UP.
ReplyDeleteIn other words, lots of space, lots of time, and a lot to conjecture. Except that some areas were for climatic reasons closer to modern human preferences than others.
But genetically we can infer that there were not so many changes and that the changes that affected much of Eurasia (Y-DNA MNOPS and mtDNA R related) also affected areas of clear Denisovan introgression (Melanesia), where they did not cause an impact that we can discern by comparing with, for example, Australian Aborigines (who lack these lineages).
DeleteAnyhow, as I see it, it is pretty clear that the Eurasian colonization was as follows (give or take some details):
1. Proto-Eurasian coalescence in Arabia, coalescence of Y-DNA CF and (later?) pre-D, diverse mtDNA mostly from L3'4 and L0 (we can see remnants today). This probably lasted till c. 80 Ka.
2. First Eurasian explosion upon arrival to South Asia c. 80 Ka ago. Y-DNA F and mt-DNA M (it's possible that Toba pruned less important lineages later on).
3. Arrival and expansion in SE Asia: Y-DNA D, C and some F-derived, notably MNOPS (may be two or three groups but not too clear). MtDNA N and M-derived. Some of these arrived pre-Toba surely (the famous fast coastal migration, whether it's strictly coastal or not so much) and others may have arrived later on or benefited from Toba's partial wipings.
4. Arrival to Australasia: Y-DNA derived from C and MNOPS, mtDNA derived from N, M and R. Again this may be two waves: C with N and M first, then MNOPS with essentially R.
5. Expansion of Y-DNA MNOPS and mtDNA R (not always strictly these two but they set up the pattern). One flux to Melanesia (already mentioned), another to South Asia and then West Eurasia (P) and a third one in SE and East Asia (NO).
6. Colonization of West Eurasia (incl. Central Asia and parts of North Africa), probably simultaneous to the arrival to Coastal Siberia and nearby areas by the East (C3, D2 with some very specific mtDNA lineages: M8, D, A, etc.) The coloniaztion of the West must have included Y-DNA Q, R1b, IJ, G and possibly others like T and R1a (later?) and mtDNA like N1, R0, U, JT, M1 and some other N sublineages, then very small (leading to X and N2).
And that's it more or less.
Your description of the process as a migration that happened in several stages rather than in one fell swoop immediately at the moment of Out of Africa, seems increasingly well supported now and something that was not nearly so clear even just a few years ago. I would not be nearly so confident of the details, although the scenario you outline is plausible enough.
DeleteThe story of Y-DNA D remains cryptic. The split off of DE is very ancient as is the D and E split from each other, but the archaeological evidence regarding the likely time of the first human arrivals in Tibet, in Japan, and in the Andamans, the three places where it is more prevalent now, is quite a bit after the arrival in Australasia, and the clues regarding a possible greater range at some point post-Out of Africa and pre-LGM are very thin and inconclusive.
An important unresolved issue betwen 1 and 2 and related to 6, is when West Eurasia and East Eurasia developed distinct population genetic identities and to what extent they then remixed with each other. The surprisingly thin overlap between West Eurasian and East Eurasian Neanderthal DNA attributed SNPs that John Hawks has noted and the near total lack of Y-DNA D, mtDNA M (including derivatives thereof, and some fairly basal divisions of other uniparental lineages (as well as other particular isolated autosomal markers and the overall autosomal similarity) seems to point to a very early schizm of Eurasians into Western and Eastern branches with only partial mixing of the populations at a later date. A division into Western and Eastern branches of Eurasians even before Neanderthal admixture takes place at all doesn't seem out of the realm of possibility. This suggests in turn at least two separate Out of Arabia migrations, one into South Asia and ancestral to coastal route Asians, and the other into a refuge from which West Eurasians ultimately appear (perhaps the Caucusas or Iran).
Don't take me wrong. I used numerated stages for reason of the exposition and indication of some order but, unless stated otherwise, I see no particular reason to see any stop or hiatus between the different stages and in fact it's apparent in text that they overlap and the boundaries between one and the next are not well defined. So it is "one fell swoop" but with an order, not merely amorphous.
DeleteAs for D, I think it is old because it looks displaced by O/MNOPS in the Eastern lands, exactly as C is (but with different specific geography). Also there were some key papers claiming it as very early arrival (but of course take with a pinch of salt) and then it is the strong correlation with mtDNA M-derived (and maybe also some N9-derived) lineages that seem pushed by the expansion of Y-DNA MNOPS with mtDNA R.
"... when West Eurasia and East Eurasia developed distinct population genetic identities and to what extent they then remixed with each other"?
Do you mean "West Eurasia" as we use it today (West of Pakistan) or in a greater sense (including South Asia)? Similarly "Eastern Eurasia" as East Asia or including Australasia?
Whichever the case I think that by the end of the process, step 6, the populations were very much well defined in their modern genetics. Earlier the process was more fluid and sometimes difficult to locate with the desired precision in its key episodes (both in geography and time: X happened in Bengal, Burma, Thailand or Cambodia?, was it c. 60 or more like 70 Ka ago?) but it seems that the regions become "saturated" c. 60 Ka ago (rough estimate), more or less freezing the human/genetic landscape, except for the periphery (West Eurasia, NE Asia), which was then colonized, and maybe some internal replacement processes like the Eastern expansions of Y-DNA MNOPS with mtDNA R.
"The surprisingly thin overlap between West Eurasian and East Eurasian Neanderthal DNA"...
Actually it is very thick (they overlap almost totally). The differences are anecdotal and surely attributed to mere randomness of founder effects (as introgressed H. sapiens already).
The absence of Y-DNA C, D and of mtDNA M (except M1 and some other minor lineages) in West Eurasia reflect a very intense founder effect, which is consistent with the pattern of a secondary strong expansion of a "clan" with mostly Y-DNA MNOPS and mtDNA R from SE Asia (or Bengal?) This one is very clear, I understand, but takes slightly different shapes depending which region affects - but these are merely local stories, peculiarities (whose causality, if any, we cannot unravel).
"I feel that the 'Denisovan' (H. erectus) admixture event happened either in Sundaland (where they may have been replacement) or even further away in the islands (cf. H. floresiensis, probably H. erectus)".
ReplyDeleteOn the contrary I am far more in agreement with Eurologist:
"While the current carriers of admixture live in the extreme SE Asia ..., Denisovans obviously did not".
That is what I originally suggested when the Denisova element in Papuans was first discovered.
"I don't see any genetic or archaeological signature of any such population replacement or 'marginalization' affecting wide areas"
On the contrary we have 'modern' human haplotypes expanding around the whole world at some time, presumably around the time of the admixture (I hesitate to use the words 'hybridization event').
"But genetically we can infer that there were not so many changes and that the changes that affected much of Eurasia (Y-DNA MNOPS and mtDNA R related) also affected areas of clear Denisovan introgression (Melanesia), where they did not cause an impact that we can discern by comparing with, for example, Australian Aborigines (who lack these lineages)".
Aborigines don't entirely lack mt-DNA R and haplogroups closely related to Y-DNA MNOPS. Y-DNA K2 is present in both Australia and New Guinea. Members of mt-DNA P are common to both regions as well. Other haplogroups closely related to mt-DNA R are also present in Australia: N13, N14, S and O. And you will of course remember that I believe the evidence indicates that both y-DNA MNOPS and mt-DNA R began their existence close to Wallacea. So, problem solved.
"Anyhow, as I see it, it is pretty clear that the Eurasian colonization was as follows (give or take some details)"
How does that explain the presence of a Denisova element in New Guinea/Australia?
"How does that explain the presence of a Denisova element in New Guinea/Australia?"
DeleteBecause there is no wave that could have erased a previously widespread "Denisovan" admixture, the admixture must have happened in situ in Indonesia (or somewhere very close).
It explains that "Denisovan admixture" is a misnomer for introgression from generic H. erectus asiaticus at about half the levels than "detected" (the other half would be redundant Neanderthal genetics, counted twice.
"the archaeological evidence regarding the likely time of the first human arrivals in Tibet, in Japan, and in the Andamans, the three places where it is more prevalent now, is quite a bit after the arrival in Australasia"
ReplyDeleteD is not present at all anywhere in Australasia. So the movement there is independent of any presence of D. Even though the time of the first human arrivals in Tibet, in Japan, and in the Andamans is relatively recent that doesn't at all eliminate the possibility that D reached one of those regions in ancient times but was only able to expand much later. That doesn't eliminate the possibility that it was at one time widespread, especially as we know the cooling climate would have eliminated it through much of Central Asia.
"it seems that the regions become 'saturated' c. 60 Ka ago (rough estimate), more or less freezing the human/genetic landscape"
Not really likely in fact. Don't forget that there was a severe ice age more recently than that time. That surely would have pushed humans south or into refugia for a considerable time.
"The absence of Y-DNA C, D and of mtDNA M (except M1 and some other minor lineages) in West Eurasia reflect a very intense founder effect"
I'm fairly sure that C5 has now been found in West Eurasia, specifically Arabia and Iran. Admittedly Wikipedia:
http://en.wikipedia.org/wiki/Haplogroup_C_%28Y-DNA%29
Quote:
"C5 (M356) Found with low frequency in South Asia, Central Asia, and Southwest Asia"
Of course its presence there may be the result of recent movement from South Asia, but that in turn implies C5 was concentrated in the northwest of that region.
"Because there is no wave that could have erased a previously widespread 'Denisovan' admixture, the admixture must have happened in situ in Indonesia (or somewhere very close)".
Virtually nothing in that statement is correct. The Denisovan element cannot be Indonesian 'H. erectus asiaticus'. As you pointed out yesterday, Y-DNA MNOPS cannot have possessed the Denisovan element or the element would now be widespread. And nor can mt-DNA R have carried it from any original Indonesian presence. The very reduced heterozygosity of the Altai individual shows the population spread was very small, so must have occupied a very restricted region. The Denisova element can only have been introduced to SE Asia from somewhere near the Altai. It then rapidly reached regions near SW Asia, but was diluted considerably (presumably by SE Asian H. erectus) before the population in SE Asia was able itself to expand further north and west.
As for 'no wave', you are forgetting the expansion of Y-DNA O (whether from SE Asia or from further north) which obviously did not carry the Denisova element. And mt-DNA M-derived haplogroups also expanded widely through East Asia, again without Denisova. So there is ample amount of 'wave that could have erased a previously widespread Denisovan admixture'.
"It explains that 'Denisovan admixture' is a misnomer for introgression from generic H. erectus asiaticus"
You seem to be the only one desperately clinging to that explanation.
"Don't forget that there was a severe ice age more recently than that time. That surely would have pushed humans south or into refugia for a considerable time".
DeleteMaybe or maybe not. Maybe the "refugia" were open or maybe they were closed (native resistance - and natives should have the numbers in favor in many cases at least because the cold north could not support many). Whatever the case, I'd look at the cases one by one based on factual evidence and would not make generic assumptions.
For example in rather well studied cases: the southwards Solutrean push in Western Europe is limited to SW Europe, and we know of exactly two sites in all Iberia. These sites would be conceptually influential but it's obvious that the "native" Gravettians had the upper hand and "gravettized" the intrusive Solutrean (adopted it with many modifications). So in the LGM Iberian populations stayed mostly the same and there is no detectable flow to anywhere in Southern Europe from the North (not into Italy nor the Balcans either). Hence that it has been sometimes argued that Central Europe was depopulated. However it was not 100% and some pockets of hardy people survived in Moravia and probably also around what today is the North Sea.
Instead North Africa may have been markedly colonized from Iberia in that very same period. Why the difference? Maybe the North Africans of the time were a tad less developed technologically and/or previous aridity did not allow for great numbers. Whatever the case each particular case must be considered on its own merits.
If you're going to speculate, do it on solid foundations, please, not mere fantasy genre. Thanks.
"I'm fairly sure that C5 has now been found in West Eurasia, specifically Arabia and Iran"...
DeleteDetails! It won't change the big picture.
" The Denisovan element cannot be Indonesian 'H. erectus asiaticus'".
Must be almost for sure:
http://forwhattheywereweare.blogspot.com/2012/01/denisovan-admixture-may-actually-be.html
"As you pointed out yesterday, Y-DNA MNOPS cannot have possessed the Denisovan element or the element would now be widespread. And nor can mt-DNA R have carried it from any original Indonesian presence".
You can't have it both ways. We must conclude that the MNOPS-R clan coalesced BEFORE arriving to the area of admixture, namely somewhere in ISEA. Same for Y-DNA C, mtDNA N, etc. Only the populations that crossed ISEA, eventually reaching Australasia show clear "Denisovan" hybridization signal. The conclusion is self-evident.
... "you are forgetting the expansion of Y-DNA O"...
It may have caused some major erasure in Sundaland. But we don't even have any certainty that there were Denisovan-introgressed populations in that area, so it's mere speculation as of now.
"You seem to be the only one desperately clinging to that explanation".
Obviously NOT, I insist: http://forwhattheywereweare.blogspot.com/2012/01/denisovan-admixture-may-actually-be.html
"But, generalizing from this one (very late for the H. Erectus chronology) individual to the entire hominin species re: endogamy is probably not valid. There is good reason to think that this sample is from a relict population that may have been recently forced into greater inbreeding that had been common in the past due to declining population"
ReplyDeleteI don't know about 'good reason to think', but it's possible. But isn't the evidence that the population had long been retreating? not just since the spread of modern humans? In which case we would expect to see a widening difference between Denisova and other relict H. erectus populations, not long range inter-connectedness.
"Your description of the process as a migration that happened in several stages rather than in one fell swoop immediately at the moment of Out of Africa, seems increasingly well supported now and something that was not nearly so clear even just a few years ago".
But something I have long insisted as being the case. The idea that modern humans expanded in all directions from a single 'superior' population has never made sense to me. Besides which the evidence seems obvious that all species have been formed by the backward and forward movement of subspecies within the species. A friend coined the expression, 'wave theory of evolution'. Genes flow though populations of a species as a series of waves. Some flow through the whole species, others are interrupted by geographic or tribal barriers.
"Must be almost for sure:"
ReplyDeleteLinking to your own comments on your own blog is hardly convincing evidence. The only relevant comment you quote from the original paper is:
"Instead, there may have been opportunity for European ancestors to pick up Neanderthal alleles, in the unknown part of Eurasia they existed in prior to moving into Europe, ditto and independently for the ancestors of the East Asians, while Papuan ancestors moved fairly rapidly through the zone of classical Neanderthals and picked up most of their archaic genes in the Indonesian region".
Note; 'may have been'. Hardly convincing evidence that they did, in fact, pick up the genes in Indonesia. And the author even concedes the 'Papuan ancestors moved fairly rapidly through the zone of classical Neanderthals'. While picking up Denisova genes? Denisova and Neanderthals were obviously near neighbours at the time.
"You can't have it both ways. We must conclude that the MNOPS-R clan coalesced BEFORE arriving to the area of admixture, namely somewhere in ISEA".
No difference. Whenever and wherever MNOPS coalesced it certainly spent some time in SE Asia, yet it carries no Denisova admixture around the world. Surely that would not be the case if the Denisova element in Papuans owes its origin to an ancient population in SE Asia.
"Only the populations that crossed ISEA, eventually reaching Australasia show clear 'Denisovan' hybridization signal. The conclusion is self-evident".
Exactly. So why are you so obsessed with avoiding interpreting the evidence in a manner absolutely consistent with what it indicates? The Denisova element in modern humans originated exactly where it has been found. Why make up 'evidence'?
"Same for Y-DNA C, mtDNA N, etc."
To me the evidence is overwhelming that Y-DNA C and mt-DNA N were exactly the population that carried the Denisova element to SE Asia. Any other interpretation is just playing with the evidence to make it fit some pre-existing belief.
"Obviously NOT, I insist: http://forwhattheywereweare.blogspot.com/2012/01/denisovan-admixture-may-actually-be.html"
As I pointed out, the author of the paper is nowhere near as sure on the matter as you are. And just because you claim it to be so does not make it so. Andrew did seem at that stage to be inclined to agree with your interpretation but is nowhere near as certain on the subject as you appear to be.
You're already spinning out again into a self-complacient pointless discourse.
Delete"Linking to your own comments on your own blog is hardly convincing"...
Read again. That "comment" is about a research article, as most of my "comments" (= blog articles). It has a link in it that you can follow if you dare to learn instead of bouncing heads stubbornly.
Also it'd be more interesting if you'd reply to Andrew and me separately or at least in different blocs. Intercalating both is confusing.
"Whenever and wherever MNOPS coalesced it certainly spent some time in SE Asia, yet it carries no Denisova admixture around the world. Surely that would not be the case if the Denisova element in Papuans owes its origin to an ancient population in SE Asia".
You may want to divide SE Asia in subregions here. It's probable that MNOPS coalesced in subregion A and that admixture with H. erectus happened in subregion B. Necessarily A is closer to mainland Asia and B farther, closer to Australasia instead.
For example A can be Indochina and B Sundaland, or A can be Sundaland and B Wallacea, etc.
What is clear is that back-migration from B to A after the admixture episode (which was very early in the colonization process probably) was trivial (a trickle at most). It still allows for further migration from A to B such as the Upper Paleolithc migration of "clan O" to Sundaland proposed by Tishkoff.
You can still have localized replacements such as this one but I see no evidence of mass waves of people moving forth and back across Asia and replacing each other once and again. That's weak self-complacent thinking and is not supported by the data.
I said: "Only the populations that crossed ISEA, eventually reaching Australasia show clear 'Denisovan' hybridization signal. The conclusion is self-evident".
You concede (you must). But then somehow demand that I reckon that the admixture event did not happen in ISEA precisely because only populations at or beyond ISEA show the introgression. Nonsense! Absolute lack of any logical coherence! I cannot take you seriously if you do that.
It brings me to very uncomfortable questions about your intellectual capacity and your absolute lack of self-criticism. If you continue playing dumb, I'll have to banish you.
A rhetorically able troll may be a bit more confusing than one who writes with poor SMS-English but in the end it is the same: either you discuss seriously and with respect or you do not. And you do not.
"As I pointed out, the author of the paper is nowhere near as sure on the matter as you are".
I think he is quite certain. Much more than "mystery hominid" speculators. In any case, I only pointed you there to indicate that, against your gesticulations I am not the only one claiming that the Denisova hominins are proxy of H. erectus asiaticus.
I know of more people who agree with me, some of them prehistorians. It's just common sense.
Sorry. I missed your earlier comment:
ReplyDelete"If you're going to speculate, do it on solid foundations, please, not mere fantasy genre. Thanks".
And an example of speculation on solid foundations:
"Maybe or maybe not. Maybe the 'refugia' were open or maybe they were closed"
Maybe, maybe, maybe. What are you trying to say?
"Whatever the case, I'd look at the cases one by one based on factual evidence and would not make generic assumptions".
Which is something you should do. We have all sorts of fragmented haplogroups in Central Eurasia. It is most parsimonious to think they are remnant survivors of previously more widespread representatives of the particular haplogroups.
"Hence that it has been sometimes argued that Central Europe was depopulated. However it was not 100% and some pockets of hardy people survived in Moravia and probably also around what today is the North Sea".
So you're prepared to argue depopulation in one region and against depopulation in the other. Why the inconsistency? Aren't you simply starting out with a pre-existing belief and sorting the evidence to fit?
"It may have caused some major erasure in Sundaland [Y-DNA O]".
I'm sure you've seen this:
http://dienekes.blogspot.co.nz/2012/09/progress-in-y-chromosome-phylogeny.html
Quote:
"It confirmed Hg E (Bantu), O (China) and R1b (Europe) expansions associated with the Neolithic transitions in different parts of the world"
Neolithic expansion? Exactly as I've been consistently trying to tell you. And that means a substantial erasure through most of China as well as through SE Asia.
"Obviously NOT, I insist [ the only one desperately clinging to that explanation]"
Well, how's this from John Hawks:
http://johnhawks.net/weblog/reviews/denisova/denisova-high-coverage-2012.html
"How can we explain the apparent contrast? 1. Maybe Denisovans didn't live in South or Southeast Asia at all. If not, that demands that we explain how Australians got their genes".
Seems he, for one, is nowhere near as convinced as you are of an Indonesian origin for the Denisova element in Papuans.
Please, admit that a contained "maybe" is generally more scientific than your arrogant "certainly". As I do not write normally in one-liners, you may find the answer to your qualms a lined under the "maybe" sentence.
ReplyDeleteCentral Asian haplogroups are invariably terminal branches of haplogroups from other regions. It's not any urheimat of anything (excepting Native Americans by the Y-DNA side).
"So you're prepared to argue depopulation in one region and against depopulation in the other. Why the inconsistency?"
Case by case analysis is not "inconsistency".
Whatever the case I did not argue for the depopulation of anywhere (others did in the recent past and I mentioned them, you should READ and THINK before you reply).
I argued in fact for at least partial population continuity in Middle Europe in the LGM. Anyhow, case by case based on available evidence, not pseudo-consistent (religious) generalizations.
"I'm sure you've seen this"...
Pseudoscience. Molecular-clock-o-logy charging against the windmills again. Let Don Quixote fight his own delusions that we should try to do a bit better.
I says for example: "The TMRCA of the entire tree was ~115 KYA (thousand years ago), and of the lineages outside Africa ~60 KYA" - what is so obviously wrong that it deserves no further comment (at the very least double figures).
"Neolithic expansion? Exactly as I've been consistently trying to tell you".
Not just you: but you are very wrong. Neolithic is overrated.
I think that Neolithic replacement fanatics, at least those who insist on obviously wrong molecular-clock-o-logy, should be gathered in a hall and fed while they agree with each other in their false believes for all the eternity. It's a religion!
"How can we explain the apparent contrast? 1. Maybe Denisovans didn't live in South or Southeast Asia at all. If not, that demands that we explain how Australians got their genes".
What does that mean: that they lived in Australia... Hawks seems to be implying that without saying by name. Although I doubt it. The correct answer is between mainland SEA and Australia.
Next he says is "2. Maybe the population was geographically extensive and diverse, but the genome from Denisova Cave doesn't represent it well."
Which is exactly what I say as well. Although I reach to the opposite conclusion to his:
"If so, we might discover that Sahulians actually have even more ancestry from this group".
Here he seems to be oblivious to the most likely possibility of Denisovans being in fact Neanderthal-Erectus hybrids (not just H. sapiens can hybridize, right?), so the likely result is of smaller introgression in fact (because Neanderthal admixture is counted twice separately).
"Central Asian haplogroups are invariably terminal branches of haplogroups from other regions".
ReplyDeleteOnly in your imagination. You're choosing to ignore mt-DNA A, which cannot be shown to have originated anywhere but Central Asia. And Y-DNA C3, which may have originated in the western part of Central Asia, but certainly not anywhere outside Central Asia. You are also not facing the problem of mt-DNA X's disjointed distribution across Central Asia. Even mt-DNA N1 may be Central Asian, although I agree it is just one part of N1'5. And N9 looks to have originated at least as far east as Mongolia before it moved further east to Japan and south as far as SE Asia.
"I argued in fact for at least partial population continuity in Middle Europe in the LGM".
And I argue for at least partial population continuity in Central Asia in the LGM. What is your problem?
"what is so obviously wrong that it deserves no further comment (at the very least double figures)".
Double is far too much. I tend to agree with Eurologist that 20% addition is sufficient. Perhaps 50% at most. On the other hand I doubt that we can assume regular replacement of parent haplogroups by daughter haplogroups even in quite small populations.
"Not just you: but you are very wrong. Neolithic is overrated".
It may be 'overrated', but we know it happened. We can only disagree as the the extent of replacement (or addition). The fact that many O3 terminal branches are so widespread in East Asia argues strongly in favour of fairly extreme replacement, although I tend to think 'addition' in this case. The pre-O population was quite likely quite sparse except where F-Derived haplogroups survive as a reasonable proportion.
"What does that mean: that they lived in Australia... Hawks seems to be implying that without saying by name".
Again, in your imagination. He seems to have no opinion as to where.
"Next he says is '2. Maybe the population was geographically extensive and diverse, but the genome from Denisova Cave doesn't represent it well.' Which is exactly what I say as well".
But that explanation is extremely unlikely, and he gives that possibility as number 2, so secondary option. The possibility that a population of limited genetic variety is connected somehow to some hugely widespread population does not stand any sort of close scrutiny. Unless you're going to claim that the Movius line represents not only the separation of Mode 1 and Mode 2 industries, but a separation between H. ergaster and H. erectus that lasted until 40,000 years ago. Even you would have trouble reconciling that possibility with an ability for modern humans to interbreed with a species they had split from nearly two million years ago.
"Here he seems to be oblivious to the most likely possibility of Denisovans being in fact Neanderthal-Erectus hybrids (not just H. sapiens can hybridize, right?), so the likely result is of smaller introgression in fact (because Neanderthal admixture is counted twice separately)".
Explaining the presence of a Neanderthal-Erectus hybrid in SE Asia is just as difficult as any original problem raised by the Denisova presence in Australia/New Guinea. And we still have two major problems. One, your idea still leaves the question of how the Denisova element died out except in Australia/New Guinea. Two, we still have the problem of hybrids between species separated by close on two million years. Even I have trouble accepting hybrids between species as different as that.
MtDNA A is clearly from East Asia, not "Central Asia". Y-DNA C3 is from NE Asia, not "Central Asia". MtDNA X is from West Asia, not "Central Asia", as is N1.
DeleteIt's your dreams and hallucinations, not mine, which are wasting my time here.
"And I argue for at least partial population continuity in Central Asia in the LGM. What is your problem?"
I'm not against but which is your evidence?
"... I doubt that we can assume regular replacement of parent haplogroups by daughter haplogroups even in quite small populations".
In Y-DNA at least there's no way a "parent haplogroup" can persist beyond one generation or so because every newborn boy carries at least one mutated SNP. It's all matter of finding and naming it. So in fact the Y-DNA real (not known) tree has about a thousand or more nodes (per unique lineage from Y-DNA Adam to present), only some of which we have identified so far. The phylogeny is still valid but much of the fine structure within it is not yet known.
Some of those nodes that co-exist each generation become haplogroups (large enough lineages we notice), while most others remain "private" (small) and eventually die out (because of drift). Although a few of these have managed to survive till present day since time immemorial (a mere matter of chance).
The issue is totally different in mtDNA because this one is very short (for DNA standards) and mutates only every many many generations (I estimate that once each some 100 generations or more). This fact completely changes the rules of the drift game, allowing for parent haplogroups to remain stagnant if the population is large enough ("killer mum" effect, by which daughter lineages are "drifted out", metaphorically "killed", once and again - a phenomenon usually overlooked).
...
...
DeleteHomo erectus, Denisovans:
"But that explanation is extremely unlikely"...
Not at all. It's what I have seen as blatantly obvious in the known data since day one. There is no materially documented H. denisovensis, but H. erectus and H. neanderthalensis are well known instead. We're talking H. erectus here with all likelihood and the only way to prove (or disprove) it successfully sequence other H. erectus specimens and compare.
" Even you would have trouble reconciling that possibility with an ability for modern humans to interbreed with a species they had split from nearly two million years ago".
Do lions and tigers interbreed in captivity? Yes. For how long have they diverged? Some 4-2 million years ago. Even, as happens with Homo species, tigers are larger brained than their cousins. Aren't SOME of their descendant fertile? Yes indeed: the female hybrids specifically (Haldane rule: the homogametic gender is more fertile).
I have no big problem with that in fact. However we must also accept that the inter-specific differences (as well as likely distinct communities with limited inter-species interaction) must have been major obstacles, explaining the low levels of the introgression and why it's not just admixture all over the board or even absorption of the African population (H. sapiens) by the Eurasian ones, as would be logical if there had been no barriers to admixture.
In the wild tigers and lions do not hybridize either - but it is biologically possible and maybe it happened in some not documented cases (I've watched on TV rare cases young lions and leopards playing together in the wild, even if they are deadly rivals as adults).
"Explaining the presence of a Neanderthal-Erectus hybrid in SE Asia"...
Not at all my point. The SE Asian introgressing species was almost for sure H. erectus without any Neanderthal admixture. That's my point.
Alternatively they could have some H. heidelbergensis (Hathnora hominin?) genetics in them but this must remain as of now in the realm of speculation.
The mtDNA, as well as some indicators of the autosomal DNA are unmistakable: Denisovans pre-date (at least by a major branch of their ancestry) the Sapiens-Neanderthal split. Hence they must be (by that branch) older than H. ergaster (aka H. erectus africanus, the common ancestor of Sapiens and Neanderthals ultimately) and there's only one such thing: H. erectus asiaticus, which is known to have existed in East Asia up to at least 150,000 years ago and in Wallacea up to 12,000 years ago.
Would it be a dog, you'd be bitten already.
"... your idea still leaves the question of how the Denisova element died out except in Australia/New Guinea."
DeleteAnd Wallaceans and Filipino Negritos, even if a bit more diluted.
I do not need to explain "how the Denisova element died out", if the hybridization happened in Wallacea itself, the only place where co-existence of H. sapiens with H. erectus, until almost the Neolithic, is well documented.
IF the hybdidization happened in Sundaland (my other option, cf. H. erectus soloensis for example, a big brained subspecies), then there was necessarily a secondary wave that replaced all or most of the first H. sapiens. But that has already been proposed by Sarah Tishkoff, suggesting that several clades of Y-DNA O did exactly that in Sundaland.
Two different possibilities, both of which fit well with the known data. What is impossible is that all early Asians would be replaced by early Asians themselves, managing to somehow wipe out all Denisovan but not any Neanderthal/Heidelbergensis introgression.
It's your model which makes no sense - as usual. The "Denisovan" element never really existed in meaningful amounts in mainland Asia. Whatever existed/exists must have back-migrated from the Malay Archipelago.
Sorry. Again I missed your earlier comment:
ReplyDelete"For example A can be Indochina and B Sundaland, or A can be Sundaland and B Wallacea, etc."
That leaves a huge gap between the Altai and Wallacea. How can you still claim that the Denisova element was part of an ancient geographic continuum between SE Asia and Altai? And how come it disappeared in region A? Your example explains nothing.
"You concede (you must). But then somehow demand that I reckon that the admixture event did not happen in ISEA precisely because only populations at or beyond ISEA show the introgression. Nonsense! Absolute lack of any logical coherence! I cannot take you seriously if you do that".
I certainly concede that the Denisova admixture remains today only in populations east of Wallace's Line. But that doesn't mean at all that the Denisova admixture had to have occurred at Wallace's Line, or nearby. Replacement is a necessary part of even the scenario you propose. Consequently the admixture could have happened anywhere. It is surely most parsimonious to accept it happened where the Denisova element has recently been discovered in an ancient human. Why make up some complicated story to explain the situation just because that is the way you want things to be?
"I am not the only one claiming that the Denisova hominins are proxy of H. erectus asiaticus".
So you claim the Movius Line represents the distinction between Denisovan/H. erectus and Neanderthal/H. ergaster? Perhaps we may be able to agree on that, and take things from there.
"Do lions and tigers interbreed in captivity? Yes. For how long have they diverged? Some 4-2 million years ago".
ReplyDeleteBut they do not produce fertile offspring. It is surely reasonable to suppose that Neanderthals and Denisovans produced fertile offspring, even using your theory.
"Aren't SOME of their descendant fertile? Yes indeed"
Are they? I have never heard of that.
"I've watched on TV rare cases young lions and leopards playing together in the wild, even if they are deadly rivals as adults"
But they do from fertile hybrids in captivity, so presumably have separated more recently than lions and tigers.
"However we must also accept that the inter-specific differences (as well as likely distinct communities with limited inter-species interaction) must have been major obstacles, explaining the low levels of the introgression"
We don't know if 'low levels of the introgression' or tribalism that has led to the low levels we see today. For me tribalism and continued population pressure from un-admixed H. sapiens populations is the most likely explanation, not hybrid incompatibility.
"MtDNA A is clearly from East Asia"
No it isn't. It is far more diverse in Tibet and nearby regions than it is anywhere in 'East Asia'.
"Y-DNA C3 is from NE Asia, not 'Central Asia'".
I might agree with you on that, but we don't really know yet. Dienekes mentions a recent paper that may give us more idea of the phylogeny, and so place of origin.
"MtDNA X is from West Asia, not 'Central Asia', as is N1".
Using that argument you must believe the term 'West Asia' covers a pretty huge region.
"I do not need to explain 'how the Denisova element died out', if the hybridization happened in Wallacea itself"
But you still have to explain how the Denisova element died out everywhere between the Altai and Wallacea, surviving only in those two hugely separate regions. What's more it seems it was basically the same in both regions.
"IF the hybdidization happened in Sundaland (my other option, cf. H. erectus soloensis for example, a big brained subspecies), then there was necessarily a secondary wave that replaced all or most of the first H. sapiens. But that has already been proposed by Sarah Tishkoff, suggesting that several clades of Y-DNA O did exactly that in Sundaland".
It's possible that your proposed secondary wave came from South Asia replacing the first wave, but that leaves Y-DNA C and mt-DNA first into the region, and separate from Y-DNA F and mt-DNA M. And, it means that the Y-DNA O replacement expansion was not confined to just Sundaland. It was much more extreme.
Panthera hybrids (if you'd just read a bit on the matter before opening your big mouth):
Delete"... in 1943, a fifteen-year-old hybrid between a lion and an 'Island' tiger was successfully mated with a lion at the Munich Hellabrunn Zoo. The female cub, though of delicate health, was raised to adulthood".
"Female jaguleps or lepjags [leopard-jaguar hybrids] are fertile, and when one is mated to a male lion, the offspring are referred to as lijaguleps".
"When the fertile offspring of a male lion and female jaguar mates with a leopard, the resulting offspring is referred to as a leoliguar".
"The male leopon is a fertile offspring of a male leopard and a female lion. The fertile female liguar, offspring of a female jaguar and male lion, is capable of fertilization by a leopon. Their mating, though rare, results in a leoligulor".
There is more...
It would seem that the tiger (and presumably the snow leopard, which is closest to the tiger) have some more difficulty producing fertile hybrid pantheras (but they do occasionally) but that this is not any serious problem for the more compact sub-taxon of lions, jaguars and leopards, which probably diverged some 2 million years ago (about the same age as the Homo genus).
Does that mean that all pantheras or the lion-leopard-jaguar subset are a single species? No, because in the wild they seldom or never reproduce. However the biological possibility is there.
Geography, prehistory and genetics of Asia:
DeleteTibet should be considered part of East Asia (and rather SE Asia than NE Asia), not Central Asia for all prehistorical purposes. Most of the Tibet plateau was only settled relatively late (after the LGM) from its peripheral areas of Yunnan and Sichuan. Tibet has no particular connection of any sort with Altai, ex-Soviet Central Asia or even Mongolia or Central Siberia.
MtDNA haplogroup X has two major sublineages: X1 and X2. X1 is found in the Levant and North Africa, X2 is mostly found in West Asia, except a few neolithic offshoots to Europe, etc. and a couple of sub lineages in Altai and Native North America. There's no possible doubt about X coalescing in West Asia.
And you know that. So you have one troll warning (collect too many and bye-bye forever).
Denisovans and H. sapiens in Eastern Eurasia:
Delete"But you still have to explain how the Denisova element died out everywhere between the Altai and Wallacea, surviving only in those two hugely separate regions".
That's not "the Denisova element": that's H. erectus. And H. erectus went extinct for sure. How? Not my problem as of this debate.
"It's possible that your proposed secondary wave came from South Asia replacing the first wave, but that leaves Y-DNA C and mt-DNA first into the region, and separate from Y-DNA F and mt-DNA M. And, it means that the Y-DNA O replacement expansion was not confined to just Sundaland. It was much more extreme".
Sorry but I do not understand it. The O beyond Sundaland & Philippines may well have only arrived later, since the Neolithic. But not sure if that's what you mean because it's a too-confusing too-short statement about too many lineages.
"The 'Denisovan' element never really existed in meaningful amounts in mainland Asia"
ReplyDeleteThat's a ridiculous comment seeing as how it has only been found outside of New Guinea/Australia in Altai. Surely we have to presume that at one stage it filled all the available ecological niches between those two regions.
"Whatever existed/exists must have back-migrated from the Malay Archipelago"
What evidence do you have for such a huge migration from SE Asia to Altai that could have given rise to such a small inbred population in the latter region?
"Not at all my point. The SE Asian introgressing species was almost for sure H. erectus without any Neanderthal admixture. That's my point".
But that SE Asian H. erectus seems to have had a great deal in common with a small, isolated, inbred population in Altai. That takes some explaining.
"We're talking H. erectus here with all likelihood and the only way to prove (or disprove) it successfully sequence other H. erectus specimens and compare".
We're talking (or you're talking) of a species that is spread all the way from the Altai to SE Asia and has carried a particular set of chromosomes at both extremes of its distribution for something near two million years. I agree we need to sequence H. erectus, but for many more reasons than just to find H. denisovensis'.
"Alternatively they could have some H. heidelbergensis (Hathnora hominin?) genetics in them but this must remain as of now in the realm of speculation".
What we do know is that SE Asia H. erectus became very different from H. erectus in other regions, including Central Asia. SE Asia had very little influence from H. heidelbergensis for example. So your hypothesis is actually extremely unlikely. I agree that the Denisova individual is probably largely descended from H. heidelbergensis. So you have a problem with your theory.
"It's what I have seen as blatantly obvious in the known data since day one".
It is only 'blatantly obvious' because you are determined to make the evidence fit what you already wish to believe. Other interpretations are certainly possible.
"there's only one such thing: H. erectus asiaticus, which is known to have existed in East Asia up to at least 150,000 years ago and in Wallacea up to 12,000 years ago. Would it be a dog, you'd be bitten already".
You are very far from having created a dog here. Not even a mongrel.
More Denisovan madness:
Delete"That's a ridiculous comment seeing as how it has only been found outside of New Guinea/Australia in Altai".
When I said "the Denisovan element" I mean the genetic introgression within H. sapiens, not Denisovans themselves. I always seem to overestimate your intelligence, sorry.
One thing are Denisovans or H. erectus, which are not part of our species in any way (they're just "cousins") and another thing is "the Denisovan element", the genetic introgression in our species. Even if somehow related they are clearly different things.
"What evidence do you have for such a huge migration from SE Asia to Altai that could have given rise to such a small inbred population in the latter region?"
We have plenty of evidence of H. erectus in all East Asia, including regions just 2000 km away from Altai (Northern and Central China). There's absolutely no reason why some H. erectus could not have reached Altai from there.
"But that SE Asian H. erectus seems to have had a great deal in common with a small, isolated, inbred population in Altai".
I don't say that. They just have much more in common among them than with either us or Neanderthals, because they are their own distinct branch of Humankind "sensu lato". That's enough to act as effective proxy.
However it's possible that within the H. erectus there was also their own evolutionary divergences and that eventually a species/subspecies replaced the rest maybe some 400 or 200,000 years ago, just like Neanderthals did with Heidelbergensis or we did with all the others. We don't know it but it's plausible.
But at the moment we do not even need to resort to such conjectures, just being closer to H. erectus from Indonesia than to us is enough.
"When I said 'the Denisovan element' I mean the genetic introgression within H. sapiens, not Denisovans themselves. I always seem to overestimate your intelligence, sorry".
DeleteAnd I always overestimate your knowledge of biology. You are apparently quite ignorant of basic elements. Have you ever studied the subject, even at high school? The 'Denisova element must have introgressed into H. sapiens in some region where 'Denisovans' lived. So your distinction is artificial. At present we know of only a small inbred population living in the Altai some 40,000 years ago.
"However it's possible that within the H. erectus there was also their own evolutionary divergences and that eventually a species/subspecies replaced the rest maybe some 400 or 200,000 years ago, just like Neanderthals did with Heidelbergensis or we did with all the others. We don't know it but it's plausible".
We do know that H. heidelbergensis replaced H. erectus through much of erectus' range. And heidelbergensis is probably ancestral to both Neanderthal and Denisova. But we also know that heidelbergensis did not replace erectus in SE Asia, or probably not even in East Asia.
"We have plenty of evidence of H. erectus in all East Asia, including regions just 2000 km away from Altai (Northern and Central China). There's absolutely no reason why some H. erectus could not have reached Altai from there".
And there's no reason why the introgression could not have happened somewhere between Altai and Northern China. But we know that H. erectus had remained isolated in SE Asia for nearly two million years and so almost certainly had drifted far genetically from regions reached by H. heidelbergensis.
"But at the moment we do not even need to resort to such conjectures, just being closer to H. erectus from Indonesia than to us is enough".
We don't know at all that SE Asian H. erectus was at all closely related to the small, inbred group that survived until some 40,000 years ago in Altai. In fact it is fairly unlikely.
"Sorry but I do not understand it. The O beyond Sundaland & Philippines may well have only arrived later, since the Neolithic. But not sure if that's what you mean because it's a too-confusing too-short statement about too many lineages".
The only way the 'Denisova element' could have been shared by species as far apart as SE Asia and Altai is that at some stage the 'element' had been present in all regions between. O's expansion ( and that of associated mt-DNAs) is the only possible explanation for its disappearance through the connecting region.
My distinction is NOT artificial.
Delete"The 'Denisova element must have introgressed into H. sapiens in some region where 'Denisovans' lived".
Where H. erectus lived most likely, for example in Indonesia.
I insist: affinity towards "Denisova" does not necessarily mean admixture with those individuals or that community, it means admixture with something like H. erectus.
"We do know that H. heidelbergensis replaced H. erectus through much of erectus' range".
Do we? Why the imprecision "much of erectus' range"? Pointless noise (again) as far as I am concerned. Concision is key to science.
"And heidelbergensis is probably ancestral to both Neanderthal and Denisova".
Ambiguous statement. Heidelbergensis is probably only ancestral to Denisovans via their Neanderthal ancestry (i.e. hybridization), not the mtDNA one, which is clearly pre-Heidelbergensis (i.e. H. erectus).
"And there's no reason why the introgression could not have happened somewhere between Altai and Northern China".
There is a very good reason: that the introgression is almost only found beyond Wallace Line. Australia is not in Mongolia.
"The only way the 'Denisova element' could have been shared by species as far apart as SE Asia and Altai"...
It'd be a single species prior to Neanderthal arrival and hybridization.
"is that at some stage the 'element' had been present in all regions between"...
In All East Asia for sure: Homo erectus asiaticus.
" O's expansion ( and that of associated mt-DNAs) is the only possible explanation for its disappearance through the connecting region".
Not at all: Toba, climatic fluctuations and specially the expansion of our species Homo sapiens, for which H. erectus was no rival, explain it instead. Just that prior to hybridization, just as happened in West Eurasia as well with Neanderthals in most cases.
The hybridization episodes were embedded in bottleneck/founder effects: they are rather single, localized events, not the diffuse inter-species pansexual fantasies that you may have.
"Tibet should be considered part of East Asia (and rather SE Asia than NE Asia), not Central Asia for all prehistorical purposes".
ReplyDeleteNot so long ago you were claiming SE Asia was the same as South China. You obviously change your point of view to fit whatever you're claiming at the time.
"The male leopon is a fertile offspring of a male leopard and a female lion. The fertile female liguar, offspring of a female jaguar and male lion, is capable of fertilization by a leopon. Their mating, though rare, results in a leoligulor".
That's what I said. Lions and leopards are more closely related than are lions and tigers. Lions even have faint spots, if you care to look.
"... in 1943, a fifteen-year-old hybrid between a lion and an 'Island' tiger was successfully mated with a lion at the Munich Hellabrunn Zoo. The female cub, though of delicate health, was raised to adulthood".
Only just produce a single fertile offspring in 15 years. I bet that next generation cub was infertile. I note it was 'of delicate health' so probably needed special and intensive care for it to survive.
"but that this is not any serious problem for the more compact sub-taxon of lions, jaguars and leopards, which probably diverged some 2 million years ago (about the same age as the Homo genus)".
And presumably all members of the Homo genus have always been fully capable of producing fertile offspring.
"Not so long ago you were claiming SE Asia was the same as South China".
ReplyDeleteRather South China is part of SE Asia. How is that contradictory?
The divergence age of the genus Panthera is 2-4 million years. There are almost perfectly modern lions from c. 1.7 million years ago. The tiger/snow leopard is obviously a first branch in the Panthera phylogeny, closer to the 4 million years age. The lion-leopard divide is likely of c. 2 Ma (or older).
If lions and leopards can breed almost without problems, so could sapiens and erecti, at least in principle.
You're doing things the wrong way round. Rather than looking at all the evidence objectively and then forming a theory accommodating that evidence, you have come to the problem with a belief in what the evidence will show, and consequently been forced to to propose a series of 'maybes' and 'possiblys' to explain discrepancies between the evidence and your belief.
ReplyDeleteYour belief has two huge problems. One is that it is extremely unlikely that a small, inbred population in the Altai would share a genetic element exclusively with a presumably equally isolated SE Asian population, even if two million years before they had been the same species. Even less likely if the Altai population had become a hybrid with Neanderthals. Second, if the SE Asian (Indonesian?) population had contained that element it is impossible that the element would not have been spread far and wide by the expansion of Y-DNA MNOPS and mt-DNA R.
I advise you to look at the evidence once more and then revise your belief.
"Where H. erectus lived most likely, for example in Indonesia".
An H. erectus population became established in Java very early in our history. However that population had no connection whatsoever with anything anywhere near the Altai from that time on.
"I insist: affinity towards 'Denisova' does not necessarily mean admixture with those individuals or that community, it means admixture with something like H. erectus".
An 'affinity' towards Denisova necessitates contact with it, even if only of the other members of the original hybrid population. The problem remains of explaining any Denisova survival in modern humans anywhere unless you can explain how such an 'affinity' reached SE Asia, either with H. sapiens or before that time.
"Do we? Why the imprecision 'much of erectus' range? Pointless noise (again) as far as I am concerned. Concision is key to science".
You don't know erectus' range? I assumed you would. Why don't you look it up.
"Heidelbergensis is probably only ancestral to Denisovans via their Neanderthal ancestry (i.e. hybridization), not the mtDNA one, which is clearly pre-Heidelbergensis (i.e. H. erectus)".
Even if the Denisovans are descended from erectus rather than ergaster they have still been genetically isolated from SE Asia H. erectus for an extremely long time. It is unlikely they still shared any more genes with SE Asian H. erectus than with Asian H. ergaster. In fact we know from their aDNA that Denisovans had mixed considerably with Neanderthals. SE Asia H. erectus had not.
"There is a very good reason: that the introgression is almost only found beyond Wallace Line. Australia is not in Mongolia".
Rubbish. You're (deliberately?) forgetting the region where the individual was found that started the whole thing off. One minute you're happy with introgression in Altai between Neanderthals and Denisovans and next you're arguing vehemently that it could not have occurred between modern humans and Denisovans. Which reminds me:
"We have plenty of evidence of H. erectus in all East Asia, including regions just 2000 km away from Altai (Northern and Central China). There's absolutely no reason why some H. erectus could not have reached Altai from there".
Here you're claiming H. erectus could journey through Central Asia with ease yet you've consistently claimed that supposedly advance modern humans were incapable of it.
"not the diffuse inter-species pansexual fantasies that you may have".
You're doing pretty well in that department in relation to Panthera species.
"If lions and leopards can breed almost without problems, so could sapiens and erecti, at least in principle".
Thank you. That's what I've been trying to get through to you since we first began communicating. At last.
Your "presumablys" are very much presumed... All I know is that:
Delete1. Denisovan mtDNA looks very much like being H. erectus (in relation with H. ergaster, i.e. Neanderthals and us)
2. Denisovan autosomal DNA is consistent with the population being a hybrid (although it can only be confirmed after a "purebred" H. erectus is sequenced - in due time, I presume).
3. Homo erectus and no other species is known to have existed in Eastern Asia before the arrival of H. sapiens (H. neanderthalensis in Altai but only there). We also know of remnant H. erectus floresiensis living in ISEA until the advent of Neolithic.
4. "Denisovan" introgression among us is only found (at clearly detectable levels) in Aboriginal Australasia (and some Filipino Negritos), what is absolutely incongruent with hybridization happening in Altai or nearby areas but is highly consistent with the event taking place in ISEA instead.
"a small, inbred population in the Altai"
Less "inbred" than the Karitiana for example. They have a marked bottleneck in ancient times, probably affecting all the H. erectus genus but, for Paleolithic levels, they are not really that "inbred", just the usual for Siberian-derived populations it seems.
They do not need to be excessively close to their cousins in ISEA (although they could be as well, we do not know) because they'd be in any case the closest sample we have to compare with (if you have blue and compare with red and green, green is still good enough; if you have a cow and compare with a lizard and a dog, the dog is good enough). Hence that I use the term "proxy" often. Hopefully soon a genuine H. erectus DNA will be sequenced and we will know more details.
"An 'affinity' towards Denisova necessitates contact with it"...
Not at all. Only very indirect contact: interaction with something closer to them than to us. Like H. erectus.
"You don't know erectus' range? I assumed you would. Why don't you look it up".
I know well but I also know that the term "H. erectus" is ambiguous and that Terry loves to play with ambiguity instead of being plainly sincere. So why don't you go sincere and plain and unambiguous, I'd hate you much less if you'd do.
...
...
Delete"Even if the Denisovans are descended from erectus rather than ergaster they have still been genetically isolated from SE Asia H. erectus for an extremely long time".
Not necessarily. The oldest date in Altai (precisely at Denisova) is 282,000 ± 56,000. That's your limit: 250-300 Ka.
In any case it does not matter for the essentials: a dog is still much more similar to a cow than a fish is. Similarly an isolated H. erectus would be more similar to other H. erectus than to us or to Neanderthals and would act (does act in fact) as valid proxy in genetic comparisons.
" In fact we know from their aDNA that Denisovans had mixed considerably with Neanderthals. SE Asia H. erectus had not".
That is what I think, not what "we know". People who argue for Denisova admixture 'sensu stricto' don't even bother considering if they are admixed with Neanderthals, if they are H. erectus or what they just wave the "mystery hominin" banner in an overly simplistic way, much like a Tea Party fanatic.
Unraveling what "Denisovans" may have been is not in the interest of their discourse, whose only intention is to revive long dead ideas on how Eurasia was colonized (i.e. via Central Asia). Ideas that do not match neither the genetic nor the archaeological evidence anymore.
Pathetic Teapartiness! Their logic is: what do I want to argue, let's get the "reasoning" and the "evidence" out of the magic hat as we speak. The already convinced will not protest and we may deceived some idiot in the meantime.
Pathetic! What offends me is not so much the lack of coherence but the lack of honesty. I don't have to waste my time debating with a creationist, do I? Similarly I do not have to waste my time debating with a "continental route" fanatic.
Yet here I am.
"Here you're claiming H. erectus could journey through Central Asia with ease yet you've consistently claimed that supposedly advance modern humans were incapable of it".
They were a locally adapted species (furry?), we were not. They were there before we even crossed the Red Sea altogether and much earlier in Northern China, a very cold region. I doubt we could survive a single night of freeze before we developed a sufficiently good cold-survival technology. It's nice now that the thermometer is always over 20ºC but what when it falls under 10ºC? Under 0ºC? Cold is one of our worst natural enemies.
"They were a locally adapted species (furry?), we were not".
ReplyDeleteThat doesn't seem to have stopped us interbreeding with them when we met. So presumably we could adopt any cultural adaptations they had developed.
"It's nice now that the thermometer is always over 20ºC but what when it falls under 10ºC? Under 0ºC? Cold is one of our worst natural enemies".
Tasmanian Aborigines survived reasonably well without clothes, thank you. And snow falls there several times every Winter.
"1. Denisovan mtDNA looks very much like being H. erectus (in relation with H. ergaster, i.e. Neanderthals and us)"
We don't know that at all. All we can say is that Denisova is different from Modern/Neanderthal. It 'could be' H. erectus, but we have no way of knowing how widespread the Denisova element was. Besides which, when the Denisova fossils were first found they were described as 'a new species'. And IF the Denisova element was distributed through all H. erectus it is inconceivable that the element disappeared as modern humans moved north through regions occupied by H. erectus.
"2. Denisovan autosomal DNA is consistent with the population being a hybrid (although it can only be confirmed after a 'purebred' H. erectus is sequenced - in due time, I presume)".
Possibly so. But it is extremely 'unlikely' to be SE Asian if it is indeed a hybrid with Neanderthal.
"3. Homo erectus and no other species is known to have existed in Eastern Asia before the arrival of H. sapiens (H. neanderthalensis in Altai but only there). We also know of remnant H. erectus floresiensis living in ISEA until the advent of Neolithic".
True, but H. erectus populations survived for a very long time in Zomia/South China, Zhoukoudian and through much of the region between Altai and the Upper Amur. It is very unlikely that the same genetic combinations were present in every erectus population after nearly two million years of isolation.
"4. 'Denisovan' introgression among us is only found (at clearly detectable levels) in Aboriginal Australasia (and some Filipino Negritos), what is absolutely incongruent with hybridization happening in Altai or nearby areas but is highly consistent with the event taking place in ISEA instead".
As far as I remember the individual typed was only 40,000 years old. That is more recent than the movement across Wallace's Line, so the evidence as it stands is even more incongruent with an admixture event in SE Asia. However it is quite consistent with an admixture event in the Altai involving a rapidly moving population that moved east and then south, reaching Australia soon after.
"Not necessarily. The oldest date in Altai (precisely at Denisova) is 282,000 ± 56,000. That's your limit: 250-300 Ka."
Makes it even less likely that Denisova is closely related to SE Asian H. erectus.
"Less 'inbred' than the Karitiana for example".
But inbred nevertheless. So, like the Karitiana, confined within a limited geographic region for some considerable time.
"They have a marked bottleneck in ancient times, probably affecting all the H. erectus genus"
But almost certainly not affecting SE Asian H. erectus.
"I know well but I also know that the term 'H. erectus' is ambiguous and that Terry loves to play with ambiguity instead of being plainly sincere. So why don't you go sincere and plain and unambiguous, I'd hate you much less if you'd do".
The term 'H. erectus' is not 'ambiguous', except perhaps for any distinction between it and H. ergaster. So to spell things out for you: H. erectus can be reserved for the ancient human population beyond the Movius Line and H. ergaster confined to those within it. Satisfied? I presume not.
"So presumably we could adopt any cultural adaptations they had developed".
DeleteWe could develop rocket science as well, as history eventually demonstrated, but we did not, not just yet. Hope you get my point.
It's not in any case that our kin was absorbed in their biological and cultural networks but that a couple of hybridization incidents happened here and there and that we adopted the offspring in our cultural and biological sphere. Children do not come with a culture, only genes.
"Tasmanian Aborigines survived reasonably well without clothes, thank you. And snow falls there several times every Winter".
Can you document the "without clothes" claim?
In any case Hobart for example has a minimal monthly average of 4.5ºC, with record lows of -2.8ºC (not too impressive), while Gorno-Altaysk instead has monthly average lows of -12ºC in November, -19ºC in January and -14ºC in March. The average highs for the long Siberian winter are also well below zero. Comparable or even worse for the other Altai capitals, Barnaul and Krasnoyarsk. So you really need excellent technology day and night to keep you half-warm. It's a most challenging environment.
Tasmanian aboriginals (nor me nor you without the best of modern tech) would not be able to survive in Altai (never mind the pigmentation and vit. D issues): their clothing and refuge technology was for sure not fit enough (by much) and the unfit do not survive.
"All we can say is that Denisova is different from Modern/Neanderthal".
DeleteThe mtDNA is not just different is from a branch that diverged long before the Neanderthal-Sapiens point of divergence. The only thing we know that old in Asia is H. erectus in its various avatars.
"It is very unlikely that the same genetic combinations were present in every erectus population after nearly two million years of isolation".
One: I am saying all the time that they are acting as a proxy: that "Denisovans" are not the direct source of the "Denisovan" element in us. Logically some details are lost but the comparison stands and all we have is a three-point comparison: African-Eurasian/Australasian-Denisovan, where Denisovan (diverged or not, hybrid or not) is necessarily the only thing that comes close to H. erectus in general.
Two: Besides, it's very possible that secondary (partial?) replacements happened within the H. erectus asiaticus population in all that time and that these flows made the various populations become closer, much as East Asians are now (maybe not that much close but the same tendency in any case). Just minor but repeated flows guarantee certain degree of homogenization, no strict replacement is needed but it might have happened anyhow (we just don't know enough about H. erectus asiaticus to judge).
"As far as I remember the individual typed was only 40,000 years old. That is more recent than the movement across Wallace's Line, so the evidence as it stands is even more incongruent with an admixture event in SE Asia".
They are older (> 60,000) but it does not matter much because they are a proxy not the direct source, I insist. It is if as, in a forensic investigation using AIMs, they found that the suspect has, say, Australian Aboriginal genetics. They do not know which Aboriginal individual is the source but they can narrow the investigation to that subset of the population. Similarly here we know that we are talking of something that is (at least mtDNA-wise) older than the Neanderthal-Sapiens divide but not exactly which population. The two "Denisovan" related ladies are the proxy not the suspect.
"[The c. 250 Ka date] Makes it even less likely that Denisova is closely related to SE Asian H. erectus".
They are not "closely" related just closely enough by comparison with our own much more distant relatedness of almost 2 million years.
Similarly, the Vindija Neanderthal community is not the source of the minor Neanderthal admixture in us (could not be: they are more recent in fact but they are also from Europe not West Asia or India) but a proxy.
"The term 'H. erectus' is not 'ambiguous', except perhaps for any distinction between it and H. ergaster".
For example but there are also other ambiguities. Whatever the case you are intently avoiding precision for the sake of pointless polemic. That's cheating and I hate cheaters.
"We could develop rocket science as well, as history eventually demonstrated, but we did not, not just yet. Hope you get my point".
ReplyDeleteYou certainly miss my point. It is extremely doubtful that Central Asian H. erectus relied totally on biology to survive. I think we can assume some sort of cultural adaptation. Any cultural adaptation could easily be borrowed by any incoming humans. So your comment, 'Children do not come with a culture, only genes' is totally irrelevant.
"It's not in any case that our kin was absorbed in their biological and cultural networks but that a couple of hybridization incidents happened here and there"
Your prejudice is obscuring your reasoning here. 'A couple of hybridization incidents'? Not likely. Local hybbridization was presumably quite common. The various human 'species' were presumably able to freely interbreed.
"Can you document the 'without clothes' claim?"
I've read many early explorers' accounts of first contact which all mention the Tasmanians' lack of clothes, even with snow lying on the ground. But this is the only comment I found with a quick look:
http://books.google.com.au/books/about/Another_Tasmanian_paradox.html?id=ozFoAAAAMAAJ
Quote:
"However, one problem with this ethnographic picture is that the Aborigines of Tasmania apparently made less use of clothing than did their counterparts across the Bass Strait. This Tasmanian clothing paradox, referring to the fact that the Tasmanians would be expected to use at least as much clothing as Aborigines on the southern mainland, forms the focus of this study. A systematic analysis of the ethnographic record forms the main study. It comprises first-hand observations of the use of clothing by Aborigines prior to, and in the decades following, the beginning of the colonial era, in relation to latitude and various meteorological indices. A separate study indicates not only that morphological variation within the mainland Aboriginal population manifests strong thermal trends, but also that the Tasmanian Aborigines may have developed greater morphological cold adaptations. A third study is included, in which thermal factors are explored in relation to one of the archaeological challenges posed by the Tasmanian Aborigines, namely their utilization of cave sites in the remote southwest region of the island during the latter part of the last ice age".
"while Gorno-Altaysk instead has monthly average lows of -12ºC in November, -19ºC in January and -14ºC in March. The average highs for the long Siberian winter are also well below zero".
Not just reindeer and geese are capable of migrating long distances to warmer regions, do you realise?
"Tasmanian aboriginals (nor me nor you without the best of modern tech) would not be able to survive in Altai"
So how did the Denisovans manage to do so? And any hybrids would presumably gain at least some of any genetic advantage they had.
"The mtDNA is not just different is from a branch that diverged long before the Neanderthal-Sapiens point of divergence. The only thing we know that old in Asia is H. erectus in its various avatars".
ReplyDeleteBut we also know that the opposite ends of any species strung out in its distribution as much as was Asian H. erectus are very different from each other. We can safely presume that the opposite ends of northern and eastern H. erectus were the most different from each other. In between the extremes they probably formed a cline.
"I am saying all the time that they are acting as a proxy: that 'Denisovans' are not the direct source of the 'Denisovan' element in us".
Perhaps not, but the population responsible for the Denisovan element in us must have had contact with the original population containing that element. As far as we actually 'know' the Denisova element was found in Altai. We don't 'know' whether it was found further afield, certainly not as far afield as SE Asia. So you are left with the same problem of explaining any connection between SE Asia and Altai, whether pre- or post- the presence of 'modern' humans anywhere.
"Logically some details are lost"
So you have proceeded to make them up to suit your belief. "all we have is a three-point comparison: African-Eurasian/Australasian-Denisovan, where Denisovan (diverged or not, hybrid or not) is necessarily the only thing that comes close to H. erectus in general".
You can hardly claim that at this stage in research we know completely what ancient human populations have contributed to modern humans. I would bet a large sum that more will be found.
"Besides, it's very possible that secondary (partial?) replacements happened within the H. erectus asiaticus population in all that time"
I'm quite sure that they did, just as has happened with the expansion of various modern human groups.
"we just don't know enough about H. erectus asiaticus to judge"
But I notice that hasn't slowed you down for a moment when it comes to making up reasons as to why your belief remains correct. I'd be far more cautious.
"but it does not matter much because they are a proxy not the direct source, I insist".
On what evidence do you base that claim? To me the evidence argues against any realistic genetic connection between SE Asia and the Altai during H. erectus times.
"For example but there are also other ambiguities. Whatever the case you are intently avoiding precision for the sake of pointless polemic. That's cheating and I hate cheaters".
OK. I'll be precise. In fact I'd go so far as to suggest the difference between H. erectus and H. ergaster is rather one of culture rather than genes. They're basically the same species. The Movius Line represents an extent of cultural/technological expansion and a corresponding genetic expansion only to a limited extent.
Oh dear. Have you seen this:
ReplyDeletehttp://dienekes.blogspot.co.nz/2012/09/a-slower-mutation-rate-has-implications.html
"First, the divergence between modern humans and both Neanderthals and Denisovans, which was originally estimated to be 272,000–435,000 years ago, is revised to 400,000–600,000 years ago. This is in better agreement with the range of estimated split times from mtDNA and also with the idea that the ancestral population of these groups may have been H. heidelbergensis".
So much for Denisovans being SE Asian H. erectus. And this comment from the paper is also very interesting:
"Third, revised estimates of the separation time between Africans and non-Africans suggest that this predates the appearance of modern humans in Europe and Asia by up to 60,000 years. We have suggested a scenario of exodus from Africa via an intermediate population in East Africa and the Middle East, which may fit better with growing evidence for modern human occupation of the latter region before the wider colonization of Eurasia and may provide a longer interval for Neanderthal admixture with non-African populations".
@Terry:
ReplyDeleteThat we have not sequenced (yet) a Denisovan or similar genome further south should not surprise you (the surprise is to be able to sequence the Denisovan genomes). Nor you should pretend that for that reason we have any sort of negative evidence of the presence of Denisovan-like genomes elsewhere.
You cling to your "mystery hominin" concept like a cryptozoologist to the blurry picture of a man in a gorilla suit. According to you, Denisovan is only Denisovan and cannot be related to anyone else not even like a Bushman is related to you and me (roughly their relation with other H. erectus asiaticus, besides whatever Neanderthal admixture, considering habitation dates).
You claim indirectly that Bushmen can't be used to compare with Neanderthals, as Reich did back in the day, because they are too remotely related to other Homo sapiens...
Your claim is absurd: Bushmen are sufficiently related to other H. sapiens and Denisovans are to other H. erectus, specially in an inter-species comparison as is the case.
There's not more to debate in this matter: the disagreement is clear and I do not wish to debate with a cryptozoologist of sorts. Denisovans were not yetis.
Let's agree to disagree. Can you do that much?
Miscellaneous matters:
1. Tasmanian Aborigines: it seems from your link that they did indeed use some clothing (for the pragmatical reason of warmth).
2. Reindeer migrate but only up to a point. Their winters are very harsh and many die. And they are one of the best cold-adapted large mammals and can, as you say, journey through long distances. Whatever the case I know of no evidence of the inhabitants of the Altai "migrating long distances to warmer regions" as you claim. In fact the region seems to have been an oasis of relatively good conditions in the Ice Age, judging by the many peoples inhabiting it all the time (until the LGM?) But still too cold for a naked Tasmanian.
3. How did Denisovans manage to live in such cold conditions? We do not know for sure. I speculate that H. erectus had retained a fur. Maybe Neanderthals too? But we simply don't know is the best answer.
4. "On what evidence do you base that claim?" This is a direct question that I am forced to answer directly again: on the evidence of Denisovan admixture existing only in the area of Australasia, not anywhere else.
5. "... the difference between H. erectus and H. ergaster is rather one of culture rather than genes. They're basically the same species". I'm familiar with that model and I have no major problem with it. But this only underlines the need to be precise and specific and not mischievous and captious, as you meant to be when you stated "the range of H. erectus" (which range, which H. erectus?)
6. "Have you seen this"? Indeed. Whatever the correctness behind it (which I still find faulty) It does not affect the Denisovan estimates, which are based only on archaeology (thanks Goddess!)
"Indeed. Whatever the correctness behind it (which I still find faulty) It does not affect the Denisovan estimates, which are based only on archaeology (thanks Goddess!)"
ReplyDeleteIt places Denisovans as Homo heidelbergensis, which removes them one step further from SE Asian H. erectus. As for 'which I still find faulty', haven't you been claiming consistently that the usually accepted mutation rate has been to rapid? So now that has been accepted you disagree?
"You cling to your 'mystery hominin' concept like a cryptozoologist to the blurry picture of a man in a gorilla suit".
On the contrary Maju, it is you who is clinging to a 'mystery hominin', in SE Asia. We have no evidence whatsoever of any connection between the Altai (and let's not forget, that is where the pre-modern hominin was found) and SE Asia (where we know that a different Homo species was present).
"Your claim is absurd: Bushmen are sufficiently related to other H. sapiens and Denisovans are to other H. erectus"
You are partly correct. Bushmen are closely related to other H. sapiens, but we have no idea at all how closely related Denisovans and SE Asian H. erectus were. It is almost certain they were far more distantly related than are Bushmen and other H. sapiens. As usual, you have introduced a straw man argument. The two situations are not comparable at all.
"There's not more to debate in this matter: the disagreement is clear and I do not wish to debate with a cryptozoologist of sorts. Denisovans were not yetis".
I agree. I'm wasting my time. Denisovans were not Yetis, but they were also certainly not SE Asian Homo erectus.
"Let's agree to disagree. Can you do that much?"
Agreed.
"Denisovans as Homo heidelbergensis"...
DeleteOnly if you believe in the model of this species being ancestor of H. sapiens, what I do not. For me (and many others) H. heidelbergensis is only ancestor of Neanderthals (and maybe the Hathnora hominin). The line to H. sapiens is a distinct one from H. ergaster (via H. rhodesiensis probably but certainly not via Asia in any case - because no meaningful techno-cultural backflow from Eurasia has ever been detected in Africa so early).
"As for 'which I still find faulty', haven't you been claiming consistently that the usually accepted mutation rate has been to rapid? So now that has been accepted you disagree?"
I disagree with the "molecular clock" methodology producing anything but very rough estimates (hunches) in the best case and total madness in many other cases. It's not reliable: archaeology is instead.
"We have no evidence whatsoever of any connection between the Altai (and let's not forget, that is where the pre-modern hominin was found) and SE Asia (where we know that a different Homo species was present)".
We do have ONE evidence at least: an mtDNA lineage that belongs to a branch much older than the Neanderthal-Sapiens split, i.e. older than H. ergaster, i.e. H. erectus.
Also there is no Mousterian at Denisova Cave before c. 70 Ka ago, roughly coincident with the arrival of Neanderthals to Central Asia. It could still be very different from H. erectus asiaticus but, if not H. heidelbergensis, they must descend from the first OoA branch, the one of H. erectus with Olduwayan, what still makes them closer to H. erectus asiaticus than to us or Neanderthals.
But the dates of arrival to Altai are too recent to be from that wave in my understanding (Derevianko proposed a colonization c. 800,000 years ago but no evidence so far until at least 300-250 Ka. years ago, which most likely came from the East and not the West, considering the mitochondrial DNA evidence).
"As usual, you have introduced a straw man argument. The two situations are not comparable at all".
If Khoisan diverged (fundamentally) from the rest of modern Humankind (H. sapiens) c. 250 Ka ago and proto-Denisovans (prior to Neanderthal hybridization) diverged from H. erectus asiaticus c. 250 Ka. ago, the two cases are very much comparable - parallel in fact.
"In fact the region seems to have been an oasis of relatively good conditions in the Ice Age, judging by the many peoples inhabiting it all the time (until the LGM?)"
ReplyDeleteWhy would 'an oasis of relatively good conditions in the Ice Age' be present only in Altai? Surely such 'oases' would be scattered through the Trans-Baikal region. Here is an interesting paper:
http://ejournal.anu.edu.au/index.php/bippa/article/view/86/77
Quote:
"In my personal view, the available facts suggest that the 'explosive' changes that occurred in human behaviour during the Middle-to-Upper Palaeolithic transition in South Siberia were not connected with the appearance of a new species of Homo in the region. Of course we have no proof that the originators of the Upper Palaeolithic 'behaviour set' could only be Homo sapiens sapiens, but we also have no firm evidence that the Middle Palaeolithic of South Siberia is represented only by archaic Homo sapiens. Nevertheless, although quite limited, the sum of the current anthropological data for the Middle Palaeolithic (including the Late Middle Palaeolihtic from Okladnikov Cave) deals with only one species of hominid, that is, the anthropologically modern human. Thus, we can assume that this species appeared in our region around 100,000 years ago (although this statement might appear quite speculative), contemporary with the emergence of the Middle Palaeolithic blade industries."
That date fits with the early OoA you are so supportive of.
"Only if you believe in the model of this species being ancestor of H. sapiens, what I do not. For me (and many others) H. heidelbergensis is only ancestor of Neanderthals (and maybe the Hathnora hominin)".
You may be on your own there, although science is not a democracy.
"haven't you been claiming consistently that the usually accepted mutation rate has been to rapid?"
I have actually been agnostic on the subject, but hasn't it now been accepted that it is 'too rapid'? I have occasionally suggested that may be the case.
"I disagree with the 'molecular clock' methodology producing anything but very rough estimates"
So do I, but at least we get some idea of relative timing from the molecular clock.
"We do have ONE evidence at least: an mtDNA lineage that belongs to a branch much older than the Neanderthal-Sapiens split, i.e. older than H. ergaster, i.e. H. erectus".
You're making things up again. We do NOT know that the particular mt-DNA line is H. erectus, especially not SE Asian H. erectus. You ASSUME it is because that suits your belief.
"Also there is no Mousterian at Denisova Cave before c. 70 Ka ago, roughly coincident with the arrival of Neanderthals to Central Asia".
Again, no connection with SE Asia. And the Denisova individual typed is younger than 70 kya. So the population it belonged to may have brought in the Mousterian.
"Derevianko proposed a colonization c. 800,000 years ago but no evidence so far until at least 300-250 Ka. years ago, which most likely came from the East and not the West, considering the mitochondrial DNA evidence"
What mitochondrial DNA evidence? Are you making things up again?
"If Khoisan diverged (fundamentally) from the rest of modern Humankind (H. sapiens) c. 250 Ka ago and proto-Denisovans (prior to Neanderthal hybridization) diverged from H. erectus asiaticus c. 250 Ka. ago, the two cases are very much comparable - parallel in fact".
There is no way any SE Asian has any connection to any other Homo species from about one and a half million years ago. Until the arrival of modern humans, that is.
I am pretty sure that the skeletal evidence shows Neanderthals and not H. sapiens in Altai prior to the "MP-UP transition", transition that is very similar to that of Europe or most of West Asia, in chronology a pattern.
DeleteIn addition the DNA evidence of Denisova cave shows non-modern humans ("Denisovans").
So Rubyn was wrong. Write to him about that. I guess he's noticed but maybe you could be two to agree... what is not the same as to be two to be right.
"Why would 'an oasis of relatively good conditions in the Ice Age' be present only in Altai?"
I don't know but the pattern of inhabitation suggests so. It was also important later on, after the Neolithic, maybe because south of it there's almost only semi-desert and desert. We know well that it is the only reasonable West-East corridor north of India. Further North and South it is too inhospitable but that specific corridor seems to be able to support some human life (provided some adaptions, of course).
"That date fits with the early OoA you are so supportive of".
I am not. My first option for the OoA, at least beyond Arabia, is c. 80 Ka. But an earlier date is still possible (unlikely but possible).
"We do NOT know that the particular mt-DNA line is H. erectus"...
What else can it be? At least per the three waves model (1- H. erectus, 2- H. ergaster > Neanderthal, 3- H. sapiens), which is the only one making any archaeological sense as far as I can discern, a lineage that pre-dates by a lot the Neanderthal-Sapiens divergence must be one of the first wave, H. erectus therefore.
"What mitochondrial DNA evidence?"
The one I just mentioned. The first thing we knew about Denisovans was their mtDNA. I wrote then:
The result known so far (...) is that she is almost twice more distant from us than H. neanderthalensis. The most logical conclusion is that (...) she belonged probably to a deeper branch of H. erectus.
At that time nothing was yet known about Denisovan admixture nor Denisovan autosomal DNA.
Are you forgetting things again?
"And the Denisova individual typed is younger than 70 kya. So the population it belonged to may have brought in the Mousterian".
What happened to their Neanderthal neighbors? I mean: your pseudo-reasoning is only self-serving (pseudoscience). Spare me that, thanks.