January 11, 2013

Decoding Neanderthals

I finished watching Decoding Neandertals (trailer below):



Much of what was mentioned in the program would not be new to readers of this blog. A couple of things that stood out for me was the demonstration of "Neanderthal pyrotechnics" by Wil Roebroeks. Related articles:

John Hawks also mentioned his findings about differential Neandertal admixture across Eurasia on the basis of the 1000 Genomes data, with Europeans having more than East Asians, and Tuscans having the most. This seems superficially at odds with the findings of Meyer et al. (2012), according to which:
We estimate that the proportion of Neandertal ancestry in Europe is 24% lower than in eastern Asia and South America (95% C.I. 12-36%).
It will be interesting to see Dr. Hawks's study when it is published. But, it seems to me that there might not be a real difference between the Hawks and Meyer et al. findings, because the former seem to be counting shared derived alleles, and Europeans would have more of those than East Asians, simply because they are more heterozygous across the genome, and Italians more than Britons. An ASHG 2012 abstract  also seems to  find more Neandertal-derived alleles in Europeans than in East Asians. So, it might seem that Europeans have inherited a more varied set of "stuff" from Neandertals, but East Asians inherited a larger portion of their ancestry from Neandertals overall.

On the topic of documentaries, I found the recent Prehistoric Autopsy to be extremely good, and you can probably find it fairly easily online if you don't happen to live in the UK.

33 comments:

eurologist said...

That episode was OK - I thought they were trying to stuff too much unrelated material into and therefor couldn't go into much depth.

A couple of things made me cringe, e.g., referring to the people from 500,000 ya as Neanderthals (rather than heidelbergensis). Also, I don't like Neanderthal be pronounced with an English 'th' - but perhaps that's just me.

terryt said...

"it might seem that Europeans have inherited a more varied set of 'stuff' from Neandertals, but East Asians inherited a larger portion of their ancestry from Neandertals overall".

What seems surprising to me is that East asians have any Neanderthal element at all. They are supposed to have entered East Asia from South Asia, a region where neanderthals were completely absent as far as I'm aware. The fact the east asians have any neanderthal element indicates to me that their evolution is more complicated than generally proposed.

Slumbery said...

terryt

All the Eurasians came via/from the Middle East and there were Neanderthals. Most of admixture may happened either there or even possibly in North Africa, therefore it is much older than the current population distribution.

eurologist said...

They are supposed to have entered East Asia from South Asia

Terry - but how did they get to S and SE Asia in the first (or second) place? Clearly, almost all of West Asia was Neanderthal (or Denisovan, or late erectus)territory, and had to be bridged.

On the topic of documentaries, I found the recent Prehistoric Autopsy to be extremely good...

That was quite well done. Also, nice cameo of Vicki Butler-Henderson as Alice Roberts!

;)

eurologist said...

Of course, another thing that bothers me immensely in these productions is that there is a branch of AMHs splitting of from the remainder of ooA in ~the Levant moving straight into Europe.

We know for certain, based on timing, on y-DNA, on mtDNA, and on autosomal DNA that this in fact did not happen.

Even the earliest AMH Europeans did not enter Europe from Africa or the Levant. There were at the minimum ~40,000 years, perhaps ~80,000 years of AM people living in North Africa, NE Africa, Arabia, and Pakistan/ India before any of them back-migrated to the Levant and to Europe.

terryt said...

"I don't like Neanderthal be pronounced with an English 'th' - but perhaps that's just me".

According to the rules of nomenclature the first name stands. I admit we're not talking binomial system here but to me the rule still applies. So even though the region is now spelt without the 'h' the name for the early inhabitants still applies.

Roy said...

Professor Curtis Marean was quoted in South Africa's Cape Times this week on the Pinnacle Point discoveries.
"Much of the global climate was hostile to human habitation in that age, but the south coast of South Africa provided the conditions and vegetation that our earliest ancestors needed for their survival".
"This is significant because the command of fire allowed humans to migrate out of Africa and into Europe around 50 to 60000 years ago.."
"We found that the people who lived in the caves approximately 164000 years..regularly used ochre as pigments for symbols. This is some of the earliest evidence for modern human behavior"

and NONE of this is supported by evidence.
1.Marean conveniently ignores Y-Chromosome Adam and Mitochondrial Eve's tropical origins, the ultimate original human refuge.
2.This coast is a well known fire-prone zone, to the extent that several species depend on its regularity for their propagation. The ability to create fire there at Will has NOT been demonstrated.
3.There are NO cave paintings in the estimated 80ky of occupation, he merely speculates on the "symbolic" usage of ochre.
4.We needed fire to cross the Bab-el-Mandab straits? WTF? Surely logs to float on would have sufficed?

If this is the new American way of science, we should all worry..

eurologist said...

Terry,

Again - how did S and SE Asians actually get there?

Gregory76 said...

Terry,
I take that a support for my view that much and maybe most of the ancestry of East Asians comes from the west (as I believe male O and female B and F do) rather than from the south or east (as I believe male D and C and female M, D and C do).

Tobus said...

What seems surprising to me is that East asians have any Neanderthal element at all.

My understanding was that the bulk of the Neanderthal admixture happened before the Euro/Asian split, presumably on the way through Arabia c100-50kya. That explains why Aboriginal Australians have Neanderthal admixture too.

matt said...

I'm still firmly in denial that the source of the DNA is from Neandertals. Rather I suspect the said DNA found in Neandertals todate is from crossbreeding with anatomically modern humans. This may be seen in the future when different groups of Neandertals have different sets of "human" DNA.
The Denisovan DNA for example may contain sequences present in East Asian humans over 50,000 years ago, but not present in the ancestors of Europeans.

eurologist said...

So even though the region is now spelt without the 'h' the name for the early inhabitants still applies.

The point is that "Thal" has been pronounced like "Tal" for perhaps more than 1,000 years, depending on region, and before than most likely "Dal" and not with an English "th." In this case, the German orthographic "th" used to indicate a softish "T" - unrelated to the two English fricative digraphs.

I'm still firmly in denial that the source of the DNA is from Neandertals. Rather I suspect the said DNA found in Neandertals todate is from crossbreeding with anatomically modern humans.

Some of it could be (either due to Vindija being mixed, or due to African complexity before emigration) - but likely not much, since it is absent in modern Africans.

terryt said...

"Clearly, almost all of West Asia was Neanderthal"

True.

"my view that much and maybe most of the ancestry of East Asians comes from the west (as I believe male O and female B and F do) rather than from the south or east (as I believe male D and C and female M, D and C do)".

To me the phylogeny of haplogroups indicates that both Y-DNA MNOPS and mt-DNA R originated somewhere in SE Asia. Both M and S are virtually confined to Melanesia/New Guinea although the case fro R is less clear. That would mean that both O and B/F were basically 'eastern'. I also think it is fairly clear that mt-DNA M is basically a South Asian haplogroup, although possibly from northeast India. The case for Y-DNAs C and D is more difficult to assess although I have my own view on the matter.

"I'm still firmly in denial that the source of the DNA is from Neandertals. Rather I suspect the said DNA found in Neandertals todate is from crossbreeding with anatomically modern humans".

If crossbreeding in one direction was possible surely crossbreeding in the other direction would be possible. To me it is certainly possible that some shared Neanderthal/modern genes moved in the direction you suggest.

Gregory76 said...

Terry said:
To me the phylogeny of haplogroups indicates that both Y-DNA MNOPS and mt-DNA R originated somewhere in SE Asia. Both M and S are virtually confined to Melanesia/New Guinea although the case fro R is less clear. That would mean that both O and B/F were basically 'eastern'.
I reply that the fact that M and S are confined to New Guinea/Melanesia does not mean that MNOPS originated there: it's other two descendants, P and NO, are found far from there, and its closest relative LT is from southwest and south Asia. As to B and F, their numerous close relatives are found in the Caucasoid zone.

terryt said...

"I reply that the fact that M and S are confined to New Guinea/Melanesia does not mean that MNOPS originated there: it's other two descendants, P and NO, are found far from there"

Not entirely true. O is quite close to SE Asia. In fact it is quite common in SE Asia although that presence is likely not to be 'original'. And R looks very likely to have coalesced in South Asia, not too far from SE Asia. So of the four MNOPS haplogroups we have two across Wallace's Line, one subclade of NO quite close by, and one subclae of P not too distant.

"its closest relative LT is from southwest and south Asia".

Yes, and its more distant relative, IJ, is further west still. We know that its even more distant relatives must have left Africa at some time so to me the most likely explanation is that IJK coalesced from F in SW Asia. The haplogroup then diverged with IJ remaining behind and KLT moving into South Asia. Then K(xLT) carried on east leaving LT behind. Once MNOPS had coalesced in SE Asia P began its movement back west and NO moved straight north.

Justin said...

A nice touch making the modern man a model and all the neanders ugly... way to help that image problem. I kept waiting for them to change to normal looking - or fair complexioned too, but they are still probably afraid of "white" nationalism/racism. Lame. I mean that was pretty damn stark!

Gregory76 said...

Terry,
The points you make are not enough to prove that MNOPS originated in New Guinea; they’re only enough to make that theory plausible. But a weighty reason makes my theory more preferable:
The Mongoloid phenotype, being an adaptation to extreme cold, must have originated in North Asia, so must have been carried south by some group of people. The best candidate for their male haplotype is O and the best candidate for their female haplotypes are B and F. It is unlikely that these people went from North Asia to Southeast Asia and then back again.

terryt said...

"The points you make are not enough to prove that MNOPS originated in New Guinea; they’re only enough to make that theory plausible".

But the points I made make it virtually impossible to make a convincing case for it to have coalesced anywhere else. Unless you're postulating genocide on a fairly massive scale.

"The Mongoloid phenotype, being an adaptation to extreme cold, must have originated in North Asia, so must have been carried south by some group of people. The best candidate for their male haplotype is O"

Totally agree with that. Although O is part of MNOPS I am reasonably sure that it originated in the north having moved there in the form of NO. The haplogroup NO then split with N remaining in the north, and in fact moving eventually further north, while O spread back south in three waves with the Early Chinese Neolithic.

"the best candidate for their female haplotypes are B and F. It is unlikely that these people went from North Asia to Southeast Asia and then back again".

To me both B and F are Southeast Asian haplogroups that have moved northward at some time, B even reaching America. You may find this list of mine explanatory:

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

The southward movement may have been largely male-mediated but several mt-DNAs look very likely to have accompanied O south: members of A5, N9a, M7, M8a (including C7), M9 (leading to E's presence in Borneo) and M12. These two lists complement the above link:

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

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

Ebizur said...

Gregory76 wrote,

"The Mongoloid phenotype, being an adaptation to extreme cold, must have originated in North Asia, so must have been carried south by some group of people. The best candidate for their male haplotype is O and the best candidate for their female haplotypes are B and F. It is unlikely that these people went from North Asia to Southeast Asia and then back again."

This passage of yours is so full of weird assumptions and logical fallacies that I do not know where to start.

According to physical anthropology, the "most Mongoloid" populations (i.e. the populations who are on average most physically divergent from Caucasoids, Negroids, and Australoids) are Native Americans and East Siberians, none of whom possess Y-DNA haplogroup O with notable frequency. MtDNA haplogroups B and F also are rare among East Siberians, although a subclade of haplogroup B is quite common in some Native American populations.

Furthermore, not only are the close relations or "siblings" of Y-DNA haplogroups N, O, Q, and R all confined to the area between South Asia and Oceania, as terryt has already mentioned, their "cousins," haplogroups L and T, are (mostly) confined to the area between South Asia and East Africa. Even if we assumed that your hypothesis of southward-moving populations bearing Y-DNA haplogroup O and Mongoloid phenotype were correct, we would have to posit an earlier migration from southern Asia to northern Asia to explain the presence of the ancestor of haplogroup O in northern Asia.

If there is no evidence to prove the case one way or another, such as in this case, it is best to assume the null hypothesis (i.e. that haplogroup O has originated and developed somewhere in the general area in which it is found today, between East Asia and Southeast Asia).

Lathdrinor said...

Again we are faced with the semantic burden of 19th century physical anthropological definitions. What, exactly, is 'Mongoloid' here? From my conversations with him in the past, terryt - and I believe Gregory76 also, though he is free to correct me - equates 'Mongoloid' with 'cold adaptation' and therefore with traits ie 'pale skin, epicanthic fold, high body fat.' Yet, it is obvious that Native Americans do not correspond to this caricature of 'Mongoloid.' Provided what Ebizur says is correct, using divergence from the Caucasoid-Negroid-Australoid axes as being diagnostic for 'Mongoloid' is in conflict with the 'cold adaptation' definition of 'Mongoloid.' You three are therefore talking about two different profiles entirely.

In my opinion, it is past time that we moved beyond these coded words. What's at stake here is whether O started off in the northern regions of East Eurasia, and whether they were the carriers of a set of traits thought to be 'cold adapted' to East and Southeast Asia. There are several objections to this just from stating it: ie why does O have greater diversity in the southern regions of East Eurasia, are the traits in question, which are found all the way in tropical Southeast Asia and indeed Sub-Saharan Africa, actually cold adapted? In the case that they are, do they have to have been transferred over by O carriers? For that matter, do they have to have been developed in the far north, given that climate conditions in East Asia itself was not exactly tropical?

Answers to these questions are of far greater value than bantering about whether O carriers were 'Mongoloid.'

terryt said...

"From my conversations with him in the past, terryt - and I believe Gregory76 also, though he is free to correct me - equates 'Mongoloid' with 'cold adaptation' and therefore with traits ie 'pale skin, epicanthic fold, high body fat.'"

Yes. I cannot speak for Gregory76 though.

"Yet, it is obvious that Native Americans do not correspond to this caricature of 'Mongoloid.'"

You may not be aware of it but it is extremely likely that Native Americans entered that continent via East Siberia. I'm sure you accept that much of Siberia was, and is, very cold.

"Provided what Ebizur says is correct, using divergence from the Caucasoid-Negroid-Australoid axes as being diagnostic for 'Mongoloid' is in conflict with the 'cold adaptation' definition of 'Mongoloid.'"

Incorrect. What Ebizur wrote was:

"According to physical anthropology, the 'most Mongoloid' populations (i.e. the populations who are on average most physically divergent from Caucasoids, Negroids, and Australoids) are Native Americans and East Siberians"

The 'most Mongoloid phenotype is East Siberian in origin. That includes Native Americans. That means the Mongoloid phenotype almost certainly evolved in a cold environment, unless you have some other theory.

"using divergence from the Caucasoid-Negroid-Australoid axes as being diagnostic for 'Mongoloid' is in conflict with the 'cold adaptation' definition of 'Mongoloid.'"

On the contrary, it fits exactly.

"What's at stake here is whether O started off in the northern regions of East Eurasia, and whether they were the carriers of a set of traits thought to be 'cold adapted' to East and Southeast Asia. There are several objections to this just from stating it: ie why does O have greater diversity in the southern regions of East Eurasia"

That diversity is easily explained when we remember that there are three separate Y-DNA O lines in SE Asia and South China, most likely from different regions within China.

"are the traits in question, which are found all the way in tropical Southeast Asia and indeed Sub-Saharan Africa, actually cold adapted?"

You could hardly claim the 'Mongoloid phenotype' is present in Sub-Saharan Africa. As to its presence in tropical SE Asia: again easily explained as being the result of southward movement from the Yangtze and Yellow River basins. Some of which is historical.

"In the case that they are, do they have to have been transferred over by O carriers?"

No other haplogroup(s) fits the bill.

"For that matter, do they have to have been developed in the far north, given that climate conditions in East Asia itself was not exactly tropical?"

I tend to agree with that comment. High altitude is sufficient and that fits the Chinese/Tibetan border region. We can be reasonably sure that Y-DNA O3 originated there.

"Answers to these questions are of far greater value than bantering about whether O carriers were 'Mongoloid.'"

All such questions are relevant to our evolution as a species.

eurologist said...

We shouldn't forget that cold adaptation has two requirements: extreme cold and a hunting lifestyle that does not prefer long-distance running and long arms and long legs.

Thus, Neanderthals were cold-adapted, but heidelbergensis was not. UP Europeans were not, but some coastal UP and Mesolithic NE Asians were. This is so because the polar circle and north is (was) yet another dimension of coldness, and spear thrusting in a forest or fishing and sea-mammal hunting don't require the same body type as steppe hunting.

There is no question that Beringia harbored both an internal population not particularly cold-adapted, and a coastal one strongly so - even before Na-Dene and Inuit migrations. This is why there are central and south American natives who still have cold-adapted features (short neck, short arms and legs, significant subcutaneous fat) , while plain "Indians" or those from the islands don't. Na-Dene speakers are moderately cold-adapted even in the US SW, and Inuits are of course strongly so.

Gregory76 said...

Terry,
I don’t see anything in your remarks to rule out alternative views. You say:

O is quite close to SE Asia. In fact it is quite common in SE Asia although that presence is likely not to be 'original'. And R looks very likely to have coalesced in South Asia, not too far from SE Asia. So of the four MNOPS haplogroups we have two across Wallace's Line, one subclade of NO quite close by, and one subclae of P not too distant.

That simply indicates that the border of range of haplotypes of western and northern Eurasia reaches Southeast Asia or nearby, not that they had to originate there. As to postulating genocide, I can believe in quite a bit of it, though I don’ t see that my view requires and especially large amount of it.

Ebizur,
I do believe that the ancestors of O (probably K at this point) moved north from Southwest Asia to to Central Asia, from which places their descedants went west, north and east (and from the east southward).

Ebizur and Lathdrinor,
The Mongoloid type is not typical of Amerinds, and even the type of the Eskimoan and Chukchian peoples is a watered-down Mongoloid compared to that of the Baikal or Taiga type of the Evenki, the most Mongoloid

Lathdrinor,
The Mongoloid type did not originate in East Asia because it seems to require not merely cold, but the cold of the far north, because in Western Eurasia it is not found in the climate belts corresponding to climate of North China or even Mongolia, except as the result of later migration.
The measurements made by physical anthropologists are relevant to physical anthropology, and that is certainly a part of anthropology.


Paul Levinson said...

I thought Decoding Neanderthals was excellent and overdue. I explored some of the same issues in a 1999 science fiction novel, The Silk Code.

terryt said...

"That simply indicates that the border of range of haplotypes of western and northern Eurasia reaches Southeast Asia or nearby, not that they had to originate there".

I am sure that Y-DNAs N and O did not originate in Southeast Asia. O is the male element of the population that carried the Mongoloid phenotype into that region.

"even the type of the Eskimoan and Chukchian peoples is a watered-down Mongoloid compared to that of the Baikal or Taiga type of the Evenki, the most Mongoloid"

Perhaps the Baikal?Taiga region is where N and O parted company.

Lathdrinor said...

@Gregory and terryt: eye lid folds resembling epicanthic folds are found among the Khoisan peoples of Sub-Saharan Africa, at a latitude not exactly known for its arctic conditions. The Khoisan also exhibit neoteny - a trait that, along with the aforementioned eye folds - caused 19th and 20th century anthropologists to theorize that they were the result of Asiatic migrants to Africa. Yet, modern genetic studies have shown that the Khoisan belong to very old haplotypes that predate any thus far discussed in these comments, with no known admixture between them and Mongoloid populations. The rise of the aforementioned traits among Khoisan are therefore the result of convergent evolution in a different climate condition.

To me, this says that we need to not automatically think that cold, arctic conditions are necessary for the rise of Mongoloid traits. This does not obviate specific traits belonging to Mongoloids from being the product of those conditions, but I do not envision a proto-Mongoloid population emerging from the arctic wastelands expanding across East Eurasia.

Gregory76 said...

Terry,
It is to your credit that you recognize that O originated in the north and those people whose males were O carried the Mongoloid south. We come apart over NO, and MNOPS, and K, which I think came from Central Asia rather than Southeast Asia.

terryt said...

"eye lid folds resembling epicanthic folds are found among the Khoisan peoples of Sub-Saharan Africa, at a latitude not exactly known for its arctic conditions".

It is a highly reflective environment that is the factor here, not extreme cold. Have you ever been on a desert?

"The rise of the aforementioned traits among Khoisan are therefore the result of convergent evolution in a different climate condition".

Correct.

"To me, this says that we need to not automatically think that cold, arctic conditions are necessary for the rise of Mongoloid traits".

To me the lack of facial hair is a result of a really frosty environment. An iceblock around your face all winter is not a pleasant thing to live with.

"I do not envision a proto-Mongoloid population emerging from the arctic wastelands expanding across East Eurasia".

I don't think anyone does. There are several possible candidates. The region around Lake Baikal has been continuously occupied since long before 'modern' humans appeared. The Sino-Tibetan border region is a possibility. The Upper Amur River, etc.

"We come apart over NO, and MNOPS, and K, which I think came from Central Asia rather than Southeast Asia".

I agree with Maju in that greatest basal diversity is an indicator of origin. MNOPS's greatest diversity by far is around Southern Wallacea and both sides of it. We can now be reasonably certain that Y-DNAs K1-P60, K2-P79 and K3-P261 as well as Australian K*-M9 are all haplogroups within MNOPS. Of the eight basal MNOPS haplogroups (K1, K2, K3, K*, M, NO, P and S) six of them are found only in Australia, New Guinea or the triangle contained by the Southern Wallacean islands of Sumba, Timor and Flores/Alor. That's just two haplogrouops found outside that region. Difficult to make a convincing case for a northern origin.

Gregory76 said...

Terry,
The fact that many of a lineage’s immediate descendants are found in an area is a reason, and a rather strong reason, for believing that that region is its ancestral home, but it is not decisive.
There are still weighty considerations from phenotypes to the contrary. In Africa and the western half of Eurasia there is a sequence of phenotypes corresponding to the sequence of climates from the tropics to the arctic: tall, thin Negroids in the tropics; short, thin Mediterranean Caucasoids in the subtropics; tall, more heavily built northern Caucasoids in the mid-temperate areas; and short, heavy incipient Mongoloid and Mongoloids in the subarctic and arctic—just what our knowledge of the influence of climate predicts. In the western half of Eurasia and Australasia we have something somewhat similar—Mongoloids in the subarctic and arctic of North Asia and the cold desert and semidesert of Central Asia; then south of them we have the people of mid-temperate north China, who are tall and husky like Northern Europeans; then the people of south China, who are shorter and thinner like Mediterraneans; then there are the people of Australasia and the first inhabitants of Southeast Asia—the Australians and Papuans—who are tall and thin, and in the later case, rather Negroid. However, in the first three belts, and in Southeast Asia today, we have people with epicanthic folds and other attributes we call Mongoloid, but we don’t have Negroid or Mediterranean features in the north—and so we conclude that Mongoloid moved from the north to the south (as you admit). Well the simplest way to tie this together is to say that Homo sapiens spread from Africa to northern Asia, changing much of its phenotype as it entered new climates, and then north Asians, with a Mongoloid phenotype, spread southward, sometimes mixing with but often killing or displacing prior inhabitants, and adapting to new climates, but not to the extent of losing all Mongoloid characteristics, especially retaining the epicanthic fold.
Further, it seems simpler to suppose that the ancestors of Europeans arrived by the short route through Southwest Asia and Central Asia, then to suppose that they went through Southwest Asia, South Asia, Southeast Asia, East Asia and Central Asia.
Finally, as to why so many basal descendents of K are found in Australasia, I would say that the reason is that a branch of the people with K males in southwest Asia headed eastward to Australasia, and there K gave rise to several new descendents, including M and S, while back home K’s other descendents, P and NO, outnumbered and perhaps killed off or outcompeted K, for the most part.

As to the Khoisan, I would agree they have some Mongoloid features, but for the most part do not. As to the epicanthic folds, I thought that perhaps they were a protection against wind (and there may be less wind in the Kalahari than in North Asia, but there is sand in it), but your theory about glare is also very appealing.
But in that case it suggests that the Mongoloids developed their folds in the Arctic tundra. I am tempted to say that they originated there, because in all other Mongoloid regions, the corresponding region to the west is or was originally inhabited by Caucasoids. However, we might still say that Mongoloids originated in the taiga instead, if we say that the northeast Europeans would have become fully Mongoloid if only they had been in the subarctic as long as Siberians have. In that case wind seems to be more important than glare as a cause of the folds.

terryt said...

"tall, thin Negroids in the tropics; short, thin Mediterranean Caucasoids in the subtropics; tall, more heavily built northern Caucasoids in the mid-temperate areas; and short, heavy incipient Mongoloid and Mongoloids in the subarctic and arctic—just what our knowledge of the influence of climate predicts. In the western half of Eurasia and Australasia we have something somewhat similar—Mongoloids in the subarctic and arctic of North Asia and the cold desert and semidesert of Central Asia"

Those phenotypes may be of ancient origin. The 'modern' haplogroups may have introgressed into pre-existing populations to at least some extent.

"it seems simpler to suppose that the ancestors of Europeans arrived by the short route through Southwest Asia and Central Asia, then to suppose that they went through Southwest Asia, South Asia, Southeast Asia, East Asia and Central Asia".

'Simplest' is not always 'correct'. And I'm not proposing that Europeans arrived from Central Asia. The haplogroup distribution indicates their immediate origin was South Asia, but the deeper origin of many of those haplogroups indicates SE Asia.

"as to why so many basal descendents of K are found in Australasia, I would say that the reason is that a branch of the people with K males in southwest Asia headed eastward to Australasia, and there K gave rise to several new descendents, including M and S, while back home K’s other descendents, P and NO, outnumbered and perhaps killed off or outcompeted K, for the most part".

Seems unlikely to be the case with the discovery of the M525 mutation that unites MNOPS with several K haplogroups. That suggests strongle that K1, K2, K3, M, NO, P and S all lived in a relatively small region for a period, or at least their immediate ancestors did.

Gregory76 said...

Terry,
Yes, the simplest explation isnt always best, since other factors have to be considered, but they seem to me to tip the balance in favor of my theory. It comes down to which we consider more unlikely: that MNOPS would migrate from southwest Asia to New Guinea with several of its descendants, or that NO and P would migrate all the way from New Guinea to Siberia, and in the case of P's descendant R, to Europe. You think that the former is more unlikely; I think the later is more unlikely. Counting in favor of my theory is not only Occam'a Razor, but also the severe difficulties of survival will migrating. Survival in hunter-gathering societies and agricultural societies before ox pulled plows must have been arduous; harder was the survival of a lineage over centuries and millenium. Still harder was the survival of the lineage will going through the rigors of travelling (granted, the migration was presumably usuall y undertaken because survival in the homeland had become harder or impossible).

terryt said...

"other factors have to be considered, but they seem to me to tip the balance in favor of my theory".

What 'other factors'?

"It comes down to which we consider more unlikely: that MNOPS would migrate from southwest Asia to New Guinea with several of its descendants"

It doesn't have to migrate with any of its 'descendants'. Its descendants form along the way at the advancing front.

"or that NO and P would migrate all the way from New Guinea to Siberia, and in the case of P's descendant R, to Europe"

I wouldn't actually claim 'New Guinea'. Just somewhere near Wallace's Line. Again it doesn't have to migrate with its 'descendants'. They formed on the advancing front.

"You think that the former is more unlikely; I think the later is more unlikely".

The former cannot possibly explain the presence of M, S and the various Ks only in and beyond Wallacea. P and NO's origin close by requires just two haplogroups to move long distances, not the movement of at least five haplogroups required by the second hypothesis.

"Counting in favor of my theory is not only Occam'a Razor"

No. Occam's razor favours the movement of just two haplogroups, not the movement of at least five haplogroups.

"also the severe difficulties of survival will migrating".

That problem completely disappears if we're prepared to accept the haplogroups were moving through a thus far unexploited habitat. Y-DNA R appears to be concentrated through the Ganges valley for example, thus suggesting an improved boating technology.

Anonymous said...

http://www.youtube.com/watch?v=-l0SC3bRLn8

Remember when talking about cold, the north pole would be in upper mongolia during some ice ages.