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Friday, April 27, 2018

The mystery of the Sintashta people


During the Middle to Late Bronze Age, the steppes southeast of the Ural Mountains, in what is now Russia, were home to communities of metallurgists who buried their warriors with horses and the earliest examples of the spoked-wheel battle chariot.

We don't know what they called themselves, because they didn't leave any written texts, but their archaeological culture is commonly known as Sintashta. It was named after a river near one of their main settlements; an elaborate fortified town that has also been described as an ancient metallurgical industrial center. Another of their well known settlements, very similar to Sintashta, is Arkaim, pictured below courtesy of Wikipedia.


Sintashta is arguably one of the coolest ancient cultures ever discovered by archaeologists. It's also generally accepted to be the Proto-Indo-Iranian culture, and thus linguistically ancestral to a myriad of present-day peoples of Asia, including Indo-Aryans and Persians. No wonder then, that its origin, and that of its population, have been hotly debated issues.

The leading hypothesis based on archaeological data is that Sintashta is largely derived from the more westerly and warlike Abashevo culture, which occupied much of the forest steppe north of the Black and Caspian Seas. In turn, Abashevo is usually described as an eastern offshoot of the Late Neolithic Corded Ware Culture (CWC), which is generally seen as the first Indo-European archaeological culture in Northern Europe (see here).

Below is a Principal Component Analysis (PCA) featuring 38 Sintashta individuals from the recent Narasimhan et al. 2018 preprint. Note that the main Sintashta cluster overlaps almost perfectly with the main CWC cluster. The relevant datasheet is available here.


Moreover, many ancient and present-day South and Central Asians, particularly those identified with or speaking Indo-Iranian languages, appear to be strongly attracted to the main Sintashta cluster, forming an almost perfect cline between this cluster and the likely Indus Valley diaspora individuals who show no evidence of steppe ancestry.

This is in line with mixture models based on formal statistics showing significant Sintashta-related ancestry in Indo-Iranian-speakers (for instance, see here), and high frequencies of Y-haplogroup R1a-Z93 in both the Sintashta and many Indo-Iranian-speaking populations.

Some of the Sintashta samples are outliers from the main Sintashta cluster, and that's because they harbor elevated levels of ancestry related to the Mesolithic and Neolithic foragers of Eastern Europe and/or Western Siberia. This is especially true of a pair of individuals who belong to Y-haplogroup Q. However, this doesn't contradict archaeological data, which suggest that the Sintashta community may have been multi-cultural and multi-lingual. Indeed, it's generally accepted based on historical linguistics data that there were fairly intense contacts in North Eurasia between the speakers of Proto-Indo-Iranian, Proto-Uralic and Yeniseian languages.

Thus, it appears that there's not much left to debate because ancient DNA has seemingly backed up the most widely accepted hypotheses about the origin of Sintashta and its people, and their identification mainly as Proto-Indo-Iranian-speakers.

However, a sample from a Sredny Stog II culture burial on the North Pontic steppe, in what is now eastern Ukraine, has complicated matters somewhat. This individual, known as Ukraine_Eneolithic I6561, not only clusters very strongly with the most typical Sintashta samples, but also belongs to Y-haplogroup R1a-Z93. On the other hand, none of the CWC remains sequenced to date belong to this particular subclade of R1a (although, obviously, they do belong to a host of near and far related R1a subclades).

I've never seen anyone worth reading propose that Sintashta might derive from Sredny Stog II instead of Abashevo. And no wonder, because Sredny Stog II was long gone when Sintashta appeared in the archaeological record.

But if CWC remains continue to fail to produce R1a-Z93, while, at the same time, the steppes of eastern Ukraine and surrounds are shown to be a hotbed of R1a-Z93 from the Sredny Stog to the Sintashta periods, which I think is possible, then ancient DNA might well force a serious re-examination of how the awesome Sintashta culture and people came to be.

See also...


222 comments:

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Rob said...

@ Anthro

Ah- it seems you’re unaware that Tumular groups had been in east hungry and lower Danube since 4000 BC
That’s why your models are wrong

Anthro Survey said...

@Rob

Yes, but, the thing is, how demographically important were these groups in the long run and, more importantly, what were these groups like ancestrally? Were these basically EEFs or EHG-EEF hybrids like that Chalco outlier?

Either way, Yamna itself did not form near Bulgaria even if much of its cultural package owes itself to these or sister tumular groups, but ended up expanding(refluxing, in a sense) there later on.

Rob said...

@ AnthroS
Yamnaya is a large horizon which spanned from Hungary to the urals and was preceded by several phases of kurgan culture
So no, Yamnaya didn’t form in Thrace (south Bulgaria) but in E Hungary and north Bulgaria (the Getan steppe) is no later than Yamnaya in the east
Based on the genetic data it seems that, for western Yamnaya , groups like cernavoda and konstantinova are what are important;
whilst for the Samara region it would be konstantinova moving into Khvalynsk . CWC comes from this eastern range
I would have thought you understand these basic aspects by now

vAsiSTha said...

@alberto
The 4000bc connection between Armenia and sarazm is very interesting indeed.

Chad said...

LOLZ.. Just for shits and giggles...

left pops:
Brahmin
Shahr_I_Sokhta_BA1
West_Siberia_N
Onge

right pops:
Mota
Ust_Ishim
Kostenki14
MA1
GoyetQ116-1
Vestonice16
Villabruna
ElMiron
Iron_Gates
EHG
Ganj_Dareh_N
Natufian
Anatolia_N
Boncuklu
Steppe_EMBA
Globular_Amphora
LBK_EN
Ami


best coefficients: 0.523 0.116 0.361
std. errors: 0.030 0.025 0.029

fixed pat wt dof chisq tail prob
000 0 15 6.921 0.959807 0.523 0.116 0.361

Chad said...

left pops:
Brahmin
Mala
Sappali_Tepe_BA
Krasnoyarsk_MLBA
Dali_EBA

right pops:
Mota
Ust_Ishim
Kostenki14
MA1
GoyetQ116-1
Vestonice16
Villabruna
ElMiron
Iron_Gates
EHG
Ganj_Dareh_N
Levant_N
Anatolia_N
Hajji_Firuz_ChL
Steppe_EMBA
Globular_Amphora
Ami
Onge

best coefficients: 0.604 0.243 0.081 0.072
std. errors: 0.032 0.040 0.043 0.035

fixed pat wt dof chisq tail prob
0000 0 14 17.291 0.241011 0.604 0.243 0.081 0.072

Chad said...

left pops:
Brahmin
Mala
Gonur1_BA
Sintashta
Dali_EBA

right pops:
Mota
Ust_Ishim
Kostenki14
MA1
GoyetQ116-1
Vestonice16
Villabruna
ElMiron
Iron_Gates
EHG
Ganj_Dareh_N
Levant_N
Anatolia_N
Hajji_Firuz_ChL
Steppe_EMBA
Globular_Amphora
Ami
Onge
West_Siberia_N

best coefficients: 0.611 0.254 0.059 0.077
std. errors: 0.030 0.042 0.040 0.028

fixed pat wt dof chisq tail prob
0000 0 15 17.394 0.295853 0.611 0.254 0.059 0.077

Chad said...

Malayan looks to best represent the South Indian ancestry of Brahmins. I tried to add some Iranian admixture, but it was -1.5%. So, I may need an even more West Asian source for another attempt. Certainly an interesting output.

left pops:
Brahmin
Malayan
Gonur1_BA
Dali_EBA
Sintashta

right pops:
Mota
Ust_Ishim
Kostenki14
MA1
GoyetQ116-1
Vestonice16
Villabruna
ElMiron
Iron_Gates
EHG
Ganj_Dareh_N
Anatolia_N
Hajji_Firuz_ChL
Ami
West_Siberia_N
Onge


best coefficients: 0.527 0.365 0.062 0.046
std. errors: 0.027 0.040 0.029 0.040

fixed pat wt dof chisq tail prob
0000 0 12 8.702 0.728139 0.527 0.365 0.062 0.046
0001 1 13 11.129 0.600042 0.522 0.397 0.081 0.000
0010 1 13 16.616 0.217443 0.553 0.360 0.000 0.087

Chad said...

If IVC ends up being just Iran plus something like Onge, with no Anatolian, then watch BMAC numbers jump and Sintashta or Steppe MLBA really decline. We need IVC samples to be sure. But if this Malayan represents IVC, plus a later SA admixture event into Brahmins, then BMAC is going to go way up, like it is here. We just have to wait and see what the IVC samples say.

left pops:
Brahmin
Malayan
Sappali_Tepe_BA
Krasnoyarsk_MLBA
Dali_EBA

right pops:
Mota
Ust_Ishim
Kostenki14
MA1
GoyetQ116-1
Vestonice16
Villabruna
ElMiron
Iron_Gates
EHG
Ganj_Dareh_N
Anatolia_N
Hajji_Firuz_ChL
Ami
West_Siberia_N
Onge

best coefficients: 0.508 0.364 0.043 0.085
std. errors: 0.028 0.038 0.042 0.031

fixed pat wt dof chisq tail prob
0000 0 12 8.008 0.784502 0.508 0.364 0.043 0.085
0001 1 13 15.695 0.26602 0.548 0.334 0.119 0.000
0010 1 13 9.086 0.766445 0.503 0.392 0.000 0.105

Rob said...

Nice Chad
That might answer the differences in what Anthro and I were discussing.
If Shahr-3 isn’t the optimal representation of IVC, then BMAC will rise

Davidski said...

Let's see what Fst-based models have to say. Running an Fst matrix on the new South/Central Asian data and much more right now.

Ryukendo K said...

@ Chad

Blessed post 🙏

old europe said...

@Rob and Anthro

So basically you're saying that we have now a genetic confirmation of basically the Manzura thesis.

Rob said...

@ Old Europe
There was a continuum over the epochs but it was not a static one.
Toward the 3000 BC mark, the pendulum definitely swings toward the EHG/ CHG side in terms of overall autosomal ancestry. But that's just one dimension of the puzzle, and one which is still being reconstructed. =

Anthro Survey said...

Rob

Which western yamnaya samples do you have in mind?

Again, there was an improtant, formative stage of back-n-forth interaction between "Old Europe" and "Khvalynsk horizon" taking place over the checkerboard that was Ukraine. My original point was in regards to the importance of the single digit EEF in Yamnaya which belies it.

Nevertheless, that Bulgarian Yamna is not a local but is partly descended from immigrants further to the north/east. Back and forth.

Anthro Survey said...

@Chad

Very interesting! Thanks for running.

Rob said...

@ AnthroS

"Rob

Which western yamnaya samples do you have in mind?

Again, there was an important, formative stage of back-n-forth interaction between "Old Europe" and "Khvalynsk horizon" taking place over the checkerboard that was Ukraine. My original point was in regards to the importance of the single digit EEF in Yamnaya which belies it.

Nevertheless, that Bulgarian Yamna is not a local but is partly descended from immigrants further to the north/east. Back and forth."

You're not understanding the issue. The crux of the matter is Yamnaya Bulgaria descends from local Cernavoda groups resident since at least 4000 BC who intermixed with the females of Volga-Don groups. Their presence can be tracked by the long-existing presence of I2a2a1b in Alfold LBK, EN Bulgaria, western Mariupol, Bulgarian Yamnaya, Hungarian BB, Bulgarian EBA barrows - all with significant EEF. This isn;t from Samara or any 'eastern place.
You clearly don't understand the cultural sequences nor the genetics of the region, and are thus simply modelling blindly. And there's also no point using wishy-washy terms like 'old Europe' , because the variety of EEF groups in the pre-yamnaya phase were a very distinct subset of people.

Let's analyse the basic components of western Yamnaya groups


ALPc_MN I2a2a1b (5500 BC)
Balkans_N 90.9 %
WHG 8.2 %

Ukraine_Mariupol Avg (5000 BC; many I2a2a1b)
Ukraine_Mesolithic 71.8 %
WHG 15.8 %
Balkan N 10.8
CHG 1.9 %

Yamnaya_Bulgaria - I2a2a1b (3000 BC)
Balkans_N 37 %
CHG 26.5 %
Ukraine_Mesolithic 18.5 %
Samara EHG 18 %



Now, I really can't explain it any more for you aside from giving you a puppet show.

Anthro Survey said...

@Rob

>ALPc_MN 5500 BC
>Ukraine_Mariupol Avg 5000 BC
>Western Yamnaya.
Really?
Mind you, I don't dispute that such groups contributed or were otherwise sister branches(both genetically and culturally) to EEF groups who had a formative role in "proper" Yamna's formation.

When I say "Old Europe", I don't, in fact, imply a uniform, monochrome picture of Neolithic Europe. It's used for brevity's sake here in reference to the EEF-like Neolithic cultures of Ukraine or adjacent Easter European regions.

As for the I2a? As has been discussed here on multiple occasions, the Bulgarian Yamna was I2a2a1b1b---which is omitted in the setup above. So, ultimately, I2a2a1b did arrive from the Balkans but ended up refluxing. Back and forth dynamics. Again, I don't think the Yamnaya question can be adequately answered with a simple pulse model.

Rob said...

@ Anthro

That's a strawman, I am not proposing a 'simple pulse model". Also, you- nor anyone else- haven't parsed through the rest of the calls (so don't in fact understand what is what), nor do you understand sequences of the region, even when outlined in a manner a 7 year old would understand (e.g. I2a2a1b or any derived branch does not appear in Ukraine before Mariupol. That's derivation/ migration, not 'sister' branches).
You have no position nor capacity to discuss from.

Anthro Survey said...

@Rob

Seems you're the one engaging in straw-mans.
"e.g. I2a2a1b or any derived branch does not appear in Ukraine before Mariupol"
Please point to where you see me disputing such a movement from the Balkans that would result in this.

Sister branches aren't mutually exclusive with migrations.
Ancestral stream A migrates into a zone. Mixes with locals and turns into B. B then splits into C and D. Groups C and D share a certain intrusive haplogroup not found in the previous local population, but only D contributes meaningfully to some later "horizon of interest". Thus, C is a sister branch with respect to the intrusive ancestral stream in this context. Not that complicated.

What you say about parsing through the rest of the calls goes both ways, by the way. What makes you so certain it was an influx of "Volga Don females" and not a reflux from the north? The latter is more parsimonious as things stand, but I remain open minded.

Rob said...

@ AnthroS

I understand what you're saying, but that's not a reflection of reality. You're making theoretical scenarios in place of reality.
The predecessor I2a2a1b1 found in Bulgarian Yamnaya (3000-2600 cal BC) is found in preceding pre-Bronze Age Tell site (3300 cal BC; Smyadovo) and is found in contemporary, non-Yamnaya Bronze Age Bulgarian sites. By contrast, no such lineages have been found in Ukraine Eneolithic (R1b, R1a-M417 and some Caucasus chicks). But it subsequently does appear in Catacomb period Ulan IV, east of the Dnieper.
So your scenario seems a little ass up. Points for trying though.

Anthro Survey said...

@Rob

Even if further evidence vindicates your speculations about I2a, how do you know Yamnaya groups in Bulgaria were predominantly local by their paternal origins(n being ~1)? How do you know it wasn't a mix of z2103 and local EEF Hgs? I'm not saying you're wrong, but this isn't established. At any rate, you apparently don't seem to disagree about Yamnaya_Ukr/Rus-like folks from further north making an impact, after all, but merely dispute it was male-driven.

For the chess-board region that it was, Eneolithic Ukraine 4500-3500 BC is badly under-sampled and we all know it. This was an important interaction zone consisting of Balkan-style EEFs(like the outlier dude), forest-zone WHG-rich groups and EHGs. So, it's quite parsimonious to suspect that groups of Yamnaya "proper" from Samara, Kalmykia and Ukraine obtained their EEF admixture through these mediating populations over the course of a few back-n-forth exchanges. This was my original point but somehow you chose to go off on a side tangent about groups in Bulgaria.

For the record, we do have I2a2a1b1b from Neolithic Vovnigi, as well.

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