The origins and spread of domestic horses from the Western Eurasian steppes:
Domestication of horses fundamentally transformed long-range mobility and warfare1. However, modern domesticated breeds do not descend from the earliest domestic horse lineage associated with archaeological evidence of bridling, milking and corralling at Botai, Central Asia around 3500 BC3. Other longstanding candidate regions for horse domestication, such as Iberia5 and Anatolia6, have also recently been challenged. Thus, the genetic, geographic and temporal origins of modern domestic horses have remained unknown. Here we pinpoint the Western Eurasian steppes, especially the lower Volga-Don region, as the homeland of modern domestic horses. Furthermore, we map the population changes accompanying domestication from 273 ancient horse genomes. This reveals that modern domestic horses ultimately replaced almost all other local populations as they expanded rapidly across Eurasia from about 2000 BC, synchronously with equestrian material culture, including Sintashta spoke-wheeled chariots. We find that equestrianism involved strong selection for critical locomotor and behavioural adaptations at the GSDMC and ZFPM1 genes. Our results reject the commonly held association7 between horseback riding and the massive expansion of Yamnaya steppe pastoralists into Europe around 3000 BC8,9 driving the spread of Indo-European languages10. This contrasts with the scenario in Asia where Indo-Iranian languages, chariots and horses spread together, following the early second millennium BC Sintashta culture.
And, Late Quaternary dynamics of Arctic biota from ancient environmental genomics:
During the last glacial–interglacial cycle, Arctic biotas experienced substantial climatic changes, yet the nature, extent and rate of their responses are not fully understood1,2,3,4,5,6,7,8. Here we report a large-scale environmental DNA metagenomic study of ancient plant and mammal communities, analysing 535 permafrost and lake sediment samples from across the Arctic spanning the past 50,000 years. Furthermore, we present 1,541 contemporary plant genome assemblies that were generated as reference sequences. Our study provides several insights into the long-term dynamics of the Arctic biota at the circumpolar and regional scales. Our key findings include: (1) a relatively homogeneous steppe–tundra flora dominated the Arctic during the Last Glacial Maximum, followed by regional divergence of vegetation during the Holocene epoch; (2) certain grazing animals consistently co-occurred in space and time; (3) humans appear to have been a minor factor in driving animal distributions; (4) higher effective precipitation, as well as an increase in the proportion of wetland plants, show negative effects on animal diversity; (5) the persistence of the steppe–tundra vegetation in northern Siberia enabled the late survival of several now-extinct megafauna species, including the woolly mammoth until 3.9 ± 0.2 thousand years ago (ka) and the woolly rhinoceros until 9.8 ± 0.2 ka; and (6) phylogenetic analysis of mammoth environmental DNA reveals a previously unsampled mitochondrial lineage. Our findings highlight the power of ancient environmental metagenomics analyses to advance understanding of population histories and long-term ecological dynamics.
Related to the first paper, The horse bit and bridle kicked off ancient empires – a new giant dataset tracks the societal factors that drove military technology:
Starting around 3,000 years ago, a wave of innovation began to sweep through human societies around the globe. For the next millennium the continued emergence of new technologies had a dramatic effect on the course of human history.
This era saw the advancement of the ability to control horses with bit and bridle, the spread of iron-working techniques through Eurasia that led to hardier and cheaper weapons and armor and new ways of killing from a distance, such as with crossbows and catapults. On the whole, warfare became much more deadly.
I still think this is a plausible model:
– Horses were used opportunistically on the Eurasian steppe between 3500 BC and 2000 BC
– The horse was fully domesticated 2000 BC with the emergence of the light war-chariot
– The true power of the horse as a military instrument emerged after 1000 BC due to the emergence of mounted cavalry
I can be convinced that the horse wasn’t used opportunistically but it makes the militaristic expansion of Corded Ware so much more plausible to me. We’ll see what David Anthony comes up with in the near future, as he’s on the horse-beat too…
Said enough on the Open Thread on this, so want to leave that to breathe and not spam too much so people can focus on Razib’s comments here. Slight modification to what I said there; I think I may have slightly overplayed the precedence of Potapovka before Sintashta, as slightly influenced by dna samples we have. The periodisation may not be as simple as I thought. So that might need some scrutiny! But I do think that Potapovka culture needs more looking at, as the unusual diversity in the samples we have does seem like it fits with a sudden mobility increase and people suddenly being able to travel relatively further. Also need looking at do the horses of Gonur and the BMAC – might represent a dispersal of the horse into the Oxus Civilization before Indo-Iranian spread.
It seems like we might have a “two wind” model of Indo-European spread on the table; the first wave/wind is the Yamnaya or Corded Ware spread, where they take advantage of declines in Neolithic societies in Europe*, increase in their own size and the new mobility technology of the wagon, and maybe military technology of the horse, and slowly integrate women (like 1-2/100 per generation). Followed by a second wind with this domesticated, adapted horse which spreads most easily through IE who border the steppe, but is perhaps less consistently associated with population movements, immediately. In Asia this is ultimately associated with the spread of Indo-Iranian, but the horse may have spread faster (before language). And then possibly further mobility technology advantages may have compounded?
I say “two winds”, and as per the paper “Instead of horse-mounted warfare, declining populations during the European late Neolithic may thus have opened up an opportunity for a westward expansion of steppe pastoralists”, but the two phenomena may be hard to separate entirely. Take Southern Europe. In Iberia we actually have a lot of the samples with the first steppe ancestry in interval 2400-2200 BCE, there are still quite a few I2 men with no detectable steppe ancestry by around 2200 BCE (https://imgur.com/a/LjTwwkW). That’s actually overlapping the timeframe here. So it’s plausible that the dispersal of the DOM2 horse was happening at this time and pushed the advantage in South Europe for IE cultures. Likewise Italy and “the coming of the Greeks” to Greece.
Re; Turchin’s paper, it’s likely interesting but I do find he tends to anachronistically emphasise the Eurasian steppe in the genesis of the very first empires, rather than competition between agricultural states of increasing population size. Ancient Egypt is around 3200 BCE and Akkad 2300 BCE. Even the later would be very rapid for the dispersal of these horses to catalyze it.
I appreciate your GNXP comments, Matt. Usually well above my level, but your dialogs with Razib are often illuminating (both when you agree, and when you don’t).
The horse paper cites a 1970 review claiming that horses were mounted for a couple centuries before chariots (but probably not very efficiently at first?)
https://www.jstor.org/stable/4199890?read-now=1&seq=8#page_scan_tab_contents
@AMac78, feels like a bit more like a long monologue on my part sometimes ;), thanks, I appreciate it.
I don’t remember the source, but someone claimed the early domesticated horse were too small for sustained riding, and were best used as draft animals, including chariots.
FWIW, I am reading the very thorough “Early Riders: The Beginnings of Mounted Warfare in Asia and Europe” by Robert Drews.
And what you are saying seems very much inline with his thinking. I particularly like his comments on metal bits and the spread of the mulit-part bits being important. Not because that technology is necessary for horseback riding today, but because it would have been necessary for the horseback riding of the time. The “knowing” of of the possibilities of riding came after early riding. I would add only to his thoughts that it seems very possible that one additional reason you don’t need the metallic bits is that horses themselves have been bred to be more cooperative.
Really cool paper, even more samples especially from Europe to clarify some of it would be nice in the future. Some related thoughts, having had a first read of it with probably some repetition with above posts and the OP:
I notice Kristiansen is cited for the horse cheek piece map and his work has quite a few interesting things to say about the general interconnectivity during that period. Kristiansen was also a quite migration-friendly archaeologist even when it was downplayed as a factor for more endogenous developments. Probably worth a read for people interested in the general subject (another plus of these aDNA studies generally make me want to revisit those older readings when time permits to get some sense of what people were arguing at the time and what might be going on during those periods). I don’t remember Razib’s podcast episode with him covering much of this though, rather just some earlier European-related aspects.
Tangentially, as clear on the map, Mycenaean Greece is where all those three depicted traditions of cheek pieces meet, the yellow Carpathian antler, red steppe-forest steppe bone and white Near Eastern bronze. It’s one reason, among others, why I always felt like this represents more the cosmpolitan nature of the LBA culture, which also draws a lot of other material from cultures that couldn’t plausibly be the source of proto-Greek and so weren’t considered in that role in their case, just as trade partners, rather than the often posited connection between charioteers of the forest steppe and proto-Greek speakers which would have probably arrived somewhat earlier (late EH – early MH rather than early LH) per another common scenario and connected with different steppe populations and which picture is also slowly starting to get clarified.
As for domestication, even Gimbutas and Anthony who have(/had) been strong proponents of horses have being ridden systematically quite early and might have had something to do with the IE expansions certainly thought the earliest domestication had more to do with their use as a food source. A lot of archaeologists seem to have been much more skeptical about earlier, at least more consistent riding. The above-mentioned, well-known Drews is one of them though his separate view of how charioteering was related to the very late (LBA) in his view, probably general IE expansion is now of course much less likely. Certainly the last point that Razib mentions in the OP that Drews argued for a lot seems fairly plausible.
Somogyvar-Vinkovci is interesting because it’s Vucedol related, we see steppe ancestry appearing there first half of 3rd millennium BC.
The CW data are very limited but it’s interesting that these horses don’t seem steppe-related. Instead what spreads later on is most closely related to ones found among Steppe_E(M)BA cultures, perhaps in the eastern part of the Don-Volga area. So that’s a question I have here: since those forest steppe cultures are the result of CW reflux from further west (and we also know that Yamnaya and CW probably had a recent common ancestor rather than Yamnaya -> CW), what exactly is going on here? Did they pick them up from the steppe cultures, that they ultimately ended up replacing, before this apparent intensification of a process that might have already started among the former or what might be going on? Similarly I wonder if the horses of that “intermediate” period (~ late 3rd millennium) with more limited spread around eastern Europe – Balkans – Anatolia might be related to the earlier steppe cultures, not those later horse-breeding charioteers who apparently spread them so widely though the dating there makes the window pretty tight. I have the sense that the horse slightly consistently predates the chariot too in Greece (MBA vs LBA) though that timeline is also short enough that there might be an overinterpretation going on here.
On that point, as Matt mentioned, it’s also an interesting possibility that just knowledge of domestication of the horse rather than the domesticated breeds themselves also were transmitted and so IE speakers further west could employ local horses. This was considered already before aDNA from what I remember e.g. with Beaker horse remains pointing to an apparent difference to steppe horses though some further clarification there with aDNA would be nice.
@Matt
I noticed some of the discussion over the Potapovka samples (here and elsewhere), sorry if I missed something and am repeating some points. The labels in the Harvard file from what I see are:
I0244 – (F) Russia_Potapovka_o1 2343-2039 calBCE
I0246 – (R1a) Russia_Potapovka 2468-1925 calBCE
I0419 – (R1a) Russia_Potapovka_o2 2200-1900 BCE
I7670 – (R1b) Russia_MLBA_Potapovka 2129-1940 calBCE
From what I can tell, I0246 seems to be Steppe_MLBA + WSHG, I0244 Lola-like, I0419 Steppe_MLBA and I7670 Steppe_EBA. Is your interpretation of those four similar? Then the similarly eastern position of I7670 and I0246, superficially both Steppe_EBA-like (is that why they’re the ones named as non-o, alongside I0418?), might be due to somewhat different reasons. Right now it looks like we actually have four quite differently composed individuals, though two arguably have that common core of Steppe_MLBA ancestry, that are labeled as “Potapovka”.
To speculate based on what we have so far, this might represent the beginning of the transition between the earlier R1b groups to the later R1a ones in the eastern part of the original more “core area” itself. Potapovka was seen as having similarities to the reflux forest steppe groups rather than necessarily presenting full continuity with Poltavka. At the same time you also have apparently Lola-related groups in this area. Maybe that’s what we’re seeing here. As far as I can tell, the similar transition in the western steppe is definitively with Srubnaya/Timber Grave with the samples we have so far (perhaps of some interest is that Srubnaya seems to be somewhat more eastern-shifted than e.g. Sintashta – is it extra local Steppe_EBA-like ancestry, maybe? – but I haven’t looked at that apparent small difference too much) but the often-mentioned Babino-Multiroller Ware (post-Catacomb, core area on the western steppe) hasn’t been tested. It might very well represent continuity with Catacomb as I’ve seen some papers basically argue. There are signs of apparent conflict between it and the forest steppe-related groups that end up occupying the steppe for good during the LBA period. Could be that the transition from R1b to R1a takes place during that period on the western steppe and that Babino itself is still R1b-rich.
Honestly though, I’ve seen lots of different overall scenaria in the things I’ve come across about the relationships between all those cultures so it’s always good to be more tentative, as you are being with it, rather than too certain about these things (e.g. X should look like Y). Especially with the redatings we know have happened of some interesting samples that come up from time to time and change our perception of them a lot (Alexandria individual, Yamnaya Caucasus individual etc.)
@Forgetful, yeah, I think that was right from the last time I ran the models (it’s hard to remember; I remember the levels of WSHG/Steppe_Maykop/Lola shift, but whether they fit better as WSHG/Steppe_Maykop/Lola plus Yamnaya-like Steppe_EMBA or Sintashta is harder to recall, but I think it was like you say). I think the Lola sample to me looked like some blend of mostly Steppe_Maykop and a minority later Yamnaya-like, itself.
(There was also the additional one, the woman I0418 who was called as Potapovka but has now been reclassified as within Poltavka culture, though with a much later date than any other Poltavka sample).
The archaeological scenario you’re describing does seem like it fits pretty well with the sequence of the Potapovka samples and the surrounding sample record so far. I’ll definitely keep that in mind for what this actually means. (Only thing I’d add is it does seem like the upcoming paper from Ayshin et al does seem to suggest that Catacomb were supplanted in the steppe region that was closed to the Caucasus, by the Lola Culture: “During the Bronze Age, we found in Steppe Maykop individuals a genetic link to West Siberian hunter-gatherers, a component that is absent from Yamnaya, North Caucasus and Catacomb groups, but reappears in Bronze Age individuals associated with the Lola culture”, although this may be more of a co-existence).
I guess in a very crude sense perhaps it’s like we would see a scenario where after the initial Steppe_EMBA expansion, something is happening that makes the Steppe_EMBA groups less competitive in the more eastern and more steppe biome areas of the range as we move into the late 3rd millennium, and perhaps there is some movement to the west/south for them (maybe the Multi-Roller culture is the last and most western of these)? And their former range is taken up by people who might have better technology package, while the remaining Steppe_EMBA coalesce a little bit with other populations to north and south (which aren’t very expanding at this time)?