Continuing with some thoughts about Narisimhan et al 2018 (preprint) from the previous post…
The steppe people going south
Now turning our attention to how the steppe people interacted, influenced or migrated to SC Asia, let’s first look at the Andronovo-BMAC interactions and then we’ll move further south onto the Indus Valley. I will follow the freely available (here) paper from Frachetti and Rouse 2012, Central Asia, the Steppe, and the Near East, 2500–1500 BC.
By the time of the formation of the Sintashta and Andronovo cultures, the situation further south in Asia was that of an already productive network of cultural and material exchange across a vast territory:
In the mid- to late 3rd millennium BC, centuries before the start of the BMAC, the antecedent framework for wide-scale connections between Mesopotamia, Elamite Iran, the Persian Gulf, Oman, Central Asia, and the Indus Valley was taking shape. A pioneer trade network, which Possehl (2007) has called the “Middle Asian Interaction Sphere” [MAIS] (see also Ch. II.40; Tosi and Lamberg-Karlovsky 2003) appears to have fostered the transmission of select innovations and ideologies far across Asia before the more substantial political economic formations of the 2nd millennium BC.¹
In addition to this, there was another, less known until very recently, trade network connecting BMAC with China, mediated by some nomadic pastoralist groups from the Inner Asia Mountain Corridor, found at sites like Tasbas or Begash². This Central Asian population was unrelated to the steppe people (Yamnaya, Afanasievo or later Andronovo), as evidenced by the ancient DNA sample I3447 (Dali_EBA) featured in this new preprint.
The arrival of the Sintashta/Andronovo people to the area, with their mobile pastoral economy and fast transport, found an excellent match in the urban society of the BMAC, always in need of importing raw materials and exporting manufactured products.
The links between these areas cross regions that have historically been utilized by mobile pastoralists (cf. Ratnagar 2004). If these routes were similarly exploited in the Bronze Age, mobile pastoralists would have been ideally placed to broker BMAC trade through a down-the-line exchange network (Vinogradova 1993; Christian 1998). By acting as middlemen, mobile pastoralists could have diversified their income sources without having to sacrifice a pastoral lifestyle or significantly alter their productive strategies, and, importantly, could thus establish themselves as peers rather than subjects of the BMAC communities.¹
And archaeology provides good evidence that the mobile pastoralists from the steppe were in close contacts with the BMAC:
Hiebert’s excavation at a discrete scatter of predominantly ICW ceramics, located c.1 kilometer southwest of the fortified BMAC site of Gonur South, recovered pottery belonging to both ICW and BMAC traditions and dated stylistically to the Late Bronze Age (1800–1500 BC). Hiebert considered these forms consistent with the preparation, storage, and consumption of liquids (Hiebert and Moore 2004). On the basis of these observations and the proximity of Gonur-N to Gonur South, Hiebert concluded that Gonur-N represented a short-term, mobile pastoral encampment where members of independent mobile pastoralist and BMAC communities feasted together as part of negotiations over land use (Hiebert and Moore 2004).¹
This mutually beneficial relationship was the base of the interactions between the steppe nomads and the agricultural societies from the south. No evidence of war, conquer or animosity is found, contrary to some unfounded speculations (not in academic circles, fortunately).
So what’s the cultural and genetic impact that these interactions had in the steppe to BMAC direction? In this early period (2100-1500 BCE), not much as far as we know. Apart from the exchange of some goods (Horses? Spoked wheels?), there’s not much evidence of cultural shift towards the steppe in the agricultural societies from SC Asia. From a genetic point of view we don’t see much influence either in the samples available. Dzharkutan1_BA, Bustan_BA, Sumbar_LBA or Parkhai_LBA (from around the mid 2nd mill.) don’t show any significant steppe admixture nor any Y-DNA R1a, which was almost fixed in the steppe groups. A sample that does show some small amount of steppe admixture is labelled as an outlier (I6667, Parkhai_LBA_o, 1497-1413 calBCE):
Bustan_BA (4 samples)
Dzharkutan1_BA (7 samples)
Parkhai_LBA_o (1 sample)
(Other outliers like the two Dzharkutan2_BA samples have steppe admixture, but probably acquired around the Caucasus, where they seem to come from).
However, we do know that there were steppe people moving and settling south:
As far south as Tajikistan, settlements such as Kangurt-tut and burial sites such as Zardcha Khalifa and Dashti Kozy exhibit ceramics and metallurgy with obvious parallels to late Bronze Age sites in the steppe zone (Bobomulloev 1998). These sites, roughly dated to the late 2nd millennium BC, suggest that the extension of steppe networks was intertwined with exchange vectors of southern Central Asia.¹
And we have samples from them:
Dashti_Kozy_BA (3 samples, c. 1500 BCE, all 3 females)
Kashkarchi_BA (2 samples, c. 1200-1000 BCE, both R1a-Z93 males)
The Indus Valley Civilization and the later Swat Valley culture
For the first time we got a sneak-peek into what the Indus Valley people could look like genetically. This comes from 3 samples found in the periphery of the IVC that harbour and unusual amount of Ancient Ancestral South Indian (AASI) admixture, while lacking any Anatolian related one, which makes them probable migrants from the IVC to those other places. The samples labelled as Indus_diaspora are:
- Gonur2_BA, I2123, Gonur Tepe, Turkmenistan, 2452-2140 calBCE
- Shahr-i-Sokhta_BA2, S8726, SE Iran, 3200-3000 BCE, mtDNA U2c1, Y-DNA J2a1h
- Shahr-i-Sokhta_BA3, S8728, SE Iran, 2550-2450 BCE, mtDNA R7, Y-DNA J2a
The first two of them are genetically similar, with around 15% AASI admixture, while the third one has clearly higher AASI admixture at around 40%. This makes it difficult to say which is more representative of the average, so we’ll have to wait for more samples to know about the levels of AASI in the area. But the West Eurasian part is more or less clear, as something that can be modelled as Iran_Neolithic + ANE and lacking Anatolian-related admixture in any significant degree.
Now let’s compare these samples with the later ones from the Swat Valley.
Udegram_IA (15 samples)
The Swat Valley samples are from 2 periods, the first one being around 1200-800 BCE and the second one around 500 BCE – 1 AD. The above Udegram_IA ones belong to the first period and are more or less in the average of the rest. Variation of steppe admixture between individuals is high, ranging between 0 and 20%. You can check a similar model for them here.
From the 41 samples from the first period, 21 of them yielded Y-DNA. None of them belongs to the steppe_MLBA marker R1a-Z93, and there is one R1b (but could be dubious given other R1b’s assigned in the supplements). From the later samples, 15, 6 of them yielded Y-DNA, and one of them does belong to R1a. On the mtDNA side there are more matches with steppe populations.
The burial site at Udegram from where the above samples come from is described is described in this paper³ by Massimo Vidale and Roberto Micheli. The majority of the burials had a primary and a secondary interment.
This funerary pattern was also common in the cemeteries of Katelai I, Loebanr I and Butkara II. Thanks to the anthropological analysis by Maria Letizia Pulcini, we know that at Udegram, in the majority of cases, the primary burial was a mature adult female, resting directly on the ﬂoor of the grave, followed by a secondary burial of a male, of the same age or slightly younger, but not young enough to be considered her son. In some cases, the coxal and long bones of the secondary burial had indisputable cut marks from deﬂeshing, left by metal blades that included cleavers.
All of this suggests a female-centred pattern: women were buried in megalithic graves, thereby alluding to their leading role in the household, while the remains of a male relative (?) played an important but secondary role as an ‘accessory’, joining the female occupant after a divergent and more transformative funerary process that may have involved exposure, deﬂeshing and sometimes bone-chopping.
So where does this leaves us in terms of the steppe migration theory? The archaeology and the genetics tell us that this population from the Swat Valley didn’t descend from the steppe nomads. That part is clear. They do have some steppe admixture, but it’s not much (~12%?) and mostly (or totally) from the female side. Was it due to political marriages from the steppe people involved in trade in order to secure their business (marrying their daughters to locals looks like a safest way to avoid conflicts, robberies, etc… in the risky travel across the mountains passes)? Or was it something else?
Whatever the case, the problem is that the Swat Valley is a small and isolated area, not that representative of the who north of India and Pakistan. But these samples are what we have for now. How much can we extrapolate from them and modern ones?
We can look at Figure S4.2, where the Swat Valley samples (SPGT) are plotted together with modern SC Asian populations:
What this figure shows is that the ancient samples have a significantly lower amount of steppe ancestry than expected given their amount of West Eurasian ancestry (when compared to all modern populations). Does this mean that they are an extinct population? No, not really. Some relic populations from the area (like the Kalash) do show continuity with these ancient samples, though their steppe admixture also seems to have increased (about doubled) in the last 2000 years. How? Well, we don’t really know, though it seems that all the movements from historical steppe people have been accumulating steppe ancestry in SC Asia ever since those first movements from the middle Bronze Age. Or it could be something else, I guess.
The case of R1a-Z93
From a genetic point of view, the presence of early Y-chromosome haplogroup R1a-M417 in the steppe, and then it’s daughter (or grand daughter) clade Z93 has been the single strongest argument in favour of a migration from the steppe to India. India has a high incidence of this haplogroup, just like Eastern Europe, and they both are sister clades of the Z645 parent node (Z283 in Eastern Europe and Z93 in SC Asia). Sintashta and Andronovo (and Srubnaya, Potapovka,…) are almost unanimously R1a-Z93 in their male lineages, and many modern SC Asians belong to this clade.
So a movement of people from the steppe to India is undeniable based on this fact, right? (Unless R1a-Z93 was found in SC Asia before 2100 BCE, but that was unlikely and haven’t happened so far). Well, yes, but what about the details?
The first important detail was already mentioned above: The Swat Valley samples from the Iron Age don’t have a single instance of R1a-Z93, and only one sample has it in the historical period. The paper mentions the R1a connection, but remains silent about the lack of R1a in the ancient samples.
The second important detail is that all the steppe samples belong to a subclade of Z93, that is, Z2124. We have lots of samples across space and time in the steppe, but not a single one with the sister clade L657 has been found so far. The latter is the most common clade in South Asia today. What this means is that L657 did probably arrive together with Z2124, but it was a very rare clade among the steppe populations. Its high incidence today in South Asia looks much more like local expansion of a rare but lucky lineage than a marker for any large migration, making the overall incidence of R1a in South Asia hardly relevant for historical purposes.
The marker that should be more directly linked to steppe migrations is clearly Z2124, which is not too high in South Asia (but it is high in Central Asia). Even then, the details of when and how it impacted those populations is unclear. Was it mostly during the Bronze Age or mostly during historical times? (And then there’s the founder effects in many populations, with Kyrgyz being a prime example).
You can check models with modern SC Asian populations here. The first sheet uses an AASI ghost, while the second one is the same but using Mala instead, for those who prefer avoiding a ghost (just keep in mind that Mala appears in the first sheet as 9.2% Sintashta_MLBA, so that should be accounted for on the second sheet somehow).
In the absence of any convincing archaeology, the main source for providing support to the Aryan Migration Theory (BTW, I don’t care much about semantics, but the often (mis)used work “invasion” instead of “migration” is really out of place. An invasion is what Germany during the 3rd Reich did with Poland or France: a military offensive in order to control a territory. This was not a case of Germans migrating to Poland and France to settle there. See the difference?) has been the early Vedic texts, chiefly the Rigveda. This is a book of mystical chants written in an intentionally obscure and symbolic language, for those who “understand”. It’s use as a source of historical information is limited, and the interpretations of it for historical purposes have mostly been an abuse more than anything else.
As an example, the detailed horse sacrifices have been interpreted as a prove of the steppe migrations. Leaving aside other archaeological matters (like equid burials in Mesopotamia, etc..), one question raised from within those same detailed descriptions has been the fact that the sacrificed horses, to be true horses, should have 17 pairs of ribs. From modern horses, only the Arabian Horse has (most often) 17 pairs of ribs (the rest having most often 18). So how many pairs of ribs did the Sintashta horses have? If they had 18, then the Sintashta provenance would be disproved, right? Well, here’s a counter argument I’ve heard (can’t remember where exactly right now): those 17 pairs of ribs are a symbolic reference to some constellation and not literally refer to the horse anatomy. Fair enough, but if one is going to interpret such a precise detail as a symbolic and non-realistic reference to some astronomical phenomenon, shouldn’t the same principles apply to the rest of the details?
My take on this is that we should leave the Rigveda alone, except for the linguistic analysis and very few other details that are unambiguous. Otherwise anyone can abuse the interpretation of the text to fit their own hypothesis leading to absurd and contradictory conclusions. Let’s stick to more objective data.
So all in all, what’s the verdict from all this data? The jury is still out. I think that the most clear answers will come when we get ancient DNA from those regarded as early Vedic Cultures (Cemetery H, Ochre Coloured Pottery culture,…) around the Punjab and Haryana c. 1900-1400 BCE. If those turn out to be very Sintashta-like and mostly R1a-Z93, the Aryan migration from the steppe theory will get strong support (or proved, as some will prefer to say). I will leave up to each one to decide how likely that option seems when looking at the current data.
1 – Frachetti and Rouse 2012, Central Asia, the Steppe, and the near East, 2500–1500 BC, in A Companion to the Archaeology of the Ancient Near East
2 – Spengler et al 2014, Early agriculture and crop transmission among Bronze Age mobile pastoralists of Central Eurasia
3 – Vidale, M. and Micheli, R, 2017, Protohistoric graveyards of the Swat Valley, Pakistan: new light on funerary practices and absolute chronology