Thursday, April 16, 2009

Origins of Indians: Version 11.0

Indian skull shape:
Anthropometry has been traditionally used in the reconstruction of history of particular region. This is one of its numerous pseudo-scientific applications. We know that;
- Communities of a particular lineage/s in a region can change its skull shape because of change in lifestyle (nomadic to sedentary). eg. China and Middle East
- Tribal populations because of restricted food supply and region can drift towards certain type of skull shape.
- Of course, looks of matrilineage generally prevails upon in mixed population as it's more stable. This is in the sense men move or change in any region.

However, anthropometry has been widely used to stereotype the looks of a particular region. Then employ this stereotypical look to give an identity based on present day identities to faceless old populations of that region. And there are still many people who think this is more scientific than skin colour studies to identify the groups.

But thanks to Population Genetics now we can get clear picture of old populations and their relationship to one another. Here too just like skin colour based notions, skull shape based ideas fail miserably.

Munda:
In India, it's been traditionally thought that Mundas predate Dravidians and IE speakers. Many a time their skull shape has been considered as a standard. Now we know that just like their language their main male lineage (Haplogroup O2a) is observed in Austro-Asiatic populations of SE Asia/S China. But their matrilineage is typical to India. Their looks can't be considered as a standard. We now know that their male ancestry skull shape was entirely different. Therefore, present day look of Mundas is misleading.

Other examples:
We can find such examples in other parts of the world too.
Finland:
Generally, Finnish were considered as epitome of Nordic look(Blond/Dolichocephalic). But now we know that a big chunk of male ancestry(Y-haplogroup N1c) could have had entirely different look. Only their matrilineage is completly European. Therefore, present day look of Finnish is misleading.

North Africa:
In the case of Mundas and Finnish the original male look would have resembled present day East Asian look. A similar story could be found in North Africa. Light skinned North Africans are predominantly Y-haplogroup E1b1b. This haplogroup and it's closest branch Y-haplogroup E1b1a could be found among their southern dark skinned population. But their matrilineage is predominantly European. Therefore, the present day look of North Africans is misleading. Hilariously, there are Europeans who claim ancient Egyptian civilization as their own. Those people are handicapped by American model of white skin distribution thro' European males. But European male lineages are insignificant in comparison to their female lineage either in North Africa or West Asia. Considering how patriarchy prevailed in the past, probably, dark skinned Africans have higher claim on Egyptian civlization than Europeans.

12 comments:

Maju said...

Pretty much agree with this. Except that I don't give that much importance to patrilineal ancestry.

It is especially women who transmit the culture in most cases, and of course, the ones who rear the children. From a mtDNA viewpoint (and most of autosomal) those three populations clearly belong to where we instinctively think they do.

Manjunat said...

From a mtDNA viewpoint (and most of autosomal) those three populations clearly belong to where we instinctively think they do.:-). Indeed, European men or women it makes no difference at all.

ren said...

I don't see how you two can agree when you two are holding opposite positions.

Maju is saying that despite the Y-chromosome's genetic evidence, these populations are pretty what their looks imply they are, which is what Manjunat disagrees with at the very start and at every example.

Maju said...

Well, I wrote "I pretty much agree with this" for a reason, not just politeness. Manjunat is showing that in spite of Y-DNA apparent divergences, all other factors show likeness: not just anthropometry and appearence but also overall genetics (autosomal where known, mtDNA). I just added to the de-emphasis of the patrilineal delusion of Y-DNA clades - and notice that I do not say that they are totally meaningless but just that they are not that much meaningful.

...

Btw (rather offtopic), to Ren:

I was discussing with Terry Toothill these days and one of the isues he arises a possible SE Asian origin for Y-DNA K (based on apparent local high K diversity). This raises some questions (what about IJK and L, both with a western tendency?) and I'm not really convinced but, assuming it is true, what about a rapid flow through East Asia of NOP (has to be very rapid because there's only one shared SNP), whit P moving towards Central Asia via the Altai, maybe at the time of your famous "very old" proto-Aurignacian of that area? Just a hypothesis, food for thought, you know.

Manjunat said...

Maju is championing matriliny. But I don't think it's applicable for those times as an identity.

I agree, genetically, our identity is matrilineal for that particular region. But that is entirely a different story and the implications of it for our historical identity won't be the same as patrilineally inherited non-genetic identities.

Maju said...

I am not championing matrilineage, don't get me wrong. I actually imagine that patrilineage also played a role, maybe a major one, in cultural aspects in the Paleolithic - though it's difficult to tell for sure.

What I say is that matrilineage is generally a more reliable reference for overall ancestry and that you cannot ignore in any case the role of women in keeping and reproducing culture.

Take the case of Finns for instance: we know that more than half their patrilineage is of North Asian origin, we know that they do have a 15% of autosomal component from that same area. But we find them basically, if not totally, European on phenotype and that corresponds much better with both autosomal and mithocondrial genetics. As for the language and other cultural aspects it's hard to tell in this case.

In other similar cases though language seems to correlate better with paternal ancestry: this is the case of Berbers or Indian Austroasiatics, even if phenotype, most autosomal ancestry probably and surely other less noticeable cultural elements may correlate best with the matrilineal ancestry.

terryt said...

"Now we know that just like their language their main male lineage (Haplogroup O2a) is observed in Austro-Asiatic populations of SE Asia/S China".

I'm glad to find someone else who agrees that O2a is East Asian, and didn't arise in India.

"what about a rapid flow through East Asia of NOP (has to be very rapid because there's only one shared SNP), whit P moving towards Central Asia via the Altai".

It's possible but I'd be inclined to place the common ancestor of NO and P in SE Asia actually. NO went north, possibly along the Chinese coast, to eventually separate into N and O somewhere in the north. Many O branches then moved back south and some even into India. P moved rapidly through India and out onto the Iranian Plateau. Somewhere along the way, possibly in India itself, P gave rise to Q and R.

"what about IJK and L, both with a western tendency".

The K group presumably broke up as members moved through India from the west, leaving the ancestors who formed IJ and L behind, several members of K reaching SE Asia and there forming NOP, as well as S and M.

Maju said...

Nearly everybody agrees that O2a arose in SE Asia. Please!

As for the rest enough to say that I see your elucubratuions extremely far-fetched and meaningless. If NO and P are sister clades, they must have stemmed from the same birth spot (wherever the NOP node was) and not one first and the other later. Siilarly all K clades must have done the same, including L. If K coalesced in SE Asia, L must have stemmed from there, exactly the same as M, S, NOP and T (you conveniently forget of T), as well as K*, K1, K2 ,K3 and K4.

The split of K can easily be related with that of NOP (only one UEP apart) but no with the IJK one, which is in fact closer to the F node than to the K or IJ one.

A possible explanation is then that F and IJK splits happened in South Asia in the same early phase and that K and NOP arose maybe in SE Asia (or maybe in South Asia) in a later distinct phase (2nd early expansion, maybe related to the mtDNA R explosion).

terryt said...

"If NO and P are sister clades, they must have stemmed from the same birth spot".

Exactly. That's what I said: 'I'd be inclined to place the common ancestor of NO and P in SE Asia actually'.

"Siilarly all K clades must have done the same, including L".

And T, as you say. But once the basal mutation defining K had occurred descendants of the individual in which it occurred must have spread out, possibly from India but not necessarily so, from Western Asia to SE Asia, and points in between. It was subsequent to that expansion that later mutations gave rise to the various K-derived haplogroups. Again, that is exactly what I said: 'The K group presumably broke up as members moved through India from the west, leaving the ancestors who formed IJ and L behind, several members of K reaching SE Asia and there forming NOP, as well as S and M".

Feel free to add T to that pattern if you insist. It affects the pattern not one little bit. The various K-derived haplogroups are reasonably regionally defined so it's unlikely they all spread from a single source only once all the defining mutations had occurred.

terryt said...

By the way. I'd be prepared to put a fair bit of money on the NOP expansion to, in fact, be "related to the mtDNA R explosion". I've always claimed that to be so.

Maju said...

Exactly. That's what I said: 'I'd be inclined to place the common ancestor of NO and P in SE Asia actually'.

I can tentatively agree with that. It would be about the same as the K homeland anyhow.

But once the basal mutation defining K had occurred descendants of the individual in which it occurred must have spread out, possibly from India but not necessarily so, from Western Asia to SE Asia, and points in between.

The difference between K and NOP is only one mutation! That could perfectly have happened before the K lineage really spread around or at the very first stages of it.

I'd argue that P, L and T migrated more or less together to the West - if we assume a SE Asian homeland for K. Still it's kind of odd that the only K-derived lineage in all East Asia seems to be NO. This somehow seems to relate with the "unlikely" but very real other (mtDNA) connections between South/West Asia and Sahul that seem to "skip" SE Asia (left no or few remains we can see, not even among Negritos).

It was subsequent to that expansion that later mutations gave rise to the various K-derived haplogroups.

Sure, I can agree with that too, specially when there are many mutations in between, like seems to be the case of T and L. Read the above as pre-T and pre-L migrating with P.

Again, that is exactly what I said: 'The K group presumably broke up as members moved through India from the west, leaving the ancestors who formed IJ and L behind, several members of K reaching SE Asia and there forming NOP, as well as S and M".

No. Because that would place the different K sublineages as desecendants not of K but of pre-K, much like IJ. Groups would have branched out at different stages and that would be visible in a non-starlike structure. But K has a starlike structure, what suggests that regardless of its ae of coalescence, its different branches all arose at roughly the same time and same spot, even if they migrated as "private" lineages before expanding wherever they eventually did.

Basically K driect descendants seems to expand towards South/West Asia on one side and towards Sahul in the other. Only NO breaks this pattern.

By the way. I'd be prepared to put a fair bit of money on the NOP expansion to, in fact, be "related to the mtDNA R explosion". I've always claimed that to be so.

In that case you should try to see how could this lineage be related to South Asia, as it was there where the mtDNA R explosion happened with all likelihood.

My amin objection is that mtR is dominant in West Asia but Y-K is not. IJ is instead. Maybe this might mean that is IJK as a whole, rather than K or NOP which is related to mtDNA R explosion - if anything.

In that case, I'd suely argue for a truly IJK original population in South Asia, where pre-IJ and pre-K coexisted before the Y-K and mtR explosion happened. That would allow for IJ to expand with the early mtR colonists of West Asia (though mtN1 seems older than R, it'd be hard to explain the IJ dominance otherwise).

terryt said...

"I can tentatively agree with that. It would be about the same as the K homeland anyhow".

So I've managed to widen your perspective to include SE Asia. I suppose it's a little soon to push for a more precise location: Wallacea. We'll leave it six months, by which time you will probably have seen it for yourself.