The Genetic Origin of the Indo-Europeans

[HurrianFam]

Need some help here, as I'm not fully grasping the connection between Hittites and that CLV cline. How many confirmed Hittite samples were there? I read there also was a sample from Armenia; how was genetic continuity between CLV, Armenia and Hittites confirmed? With little samples from south Pontic/Caucusus, everything looks a bit flimsy to me and I'm in doubt between either a CLV or South Caucasus/S. Pontic origin territory of early PIE, with a language shift happening on its other side of the Caucasus.

The southern end of the CLV cline is Neolithic Armenia, which I guess can account for the CHG in Bronze/Copper Age Anatolia. Meanwhile, the northern end (Eneolithic Steppe) can account for most of the ancestry of Yamnaya and much of the ancestry of Sredny Stog. 

There isn't necessarily a relationship between these things, it depends on how you think Anatolian entered Anatolia.

So the CHG in Anatolia/Hittites and in Yamnaya is reported to be from that same CHG source population in (or near) Armenia?

And how does Maykop and steppe Maykop fit into all of this, seeing as they're also CHG or CHG+EHG?

The 2022 Southern Arc paper claimed that the only major link between the Yamnaya and the Central Anatolian Bronze Age (Ovaoren, Kalehoyuk, etc) was the shared CHG ancestry from a Proto-Indo-Anatolian homeland that they identified as being most likely in the Caucasus, particularly as they couldn't detect steppe ancestry (particularly the EHG component) in Central Bronze Age Anatolian samples. We can't be certain of the ethnolinguistic identity of these individuals, but it's reasonable to assume that at least some were speakers of Anatolian languages like Hittite based on time and location. 

The new paper finds the key mixture from the CLV cline (Aknashen Neolithic, the CHG/EHG mix of the Steppe Eneolithic, etc) in both Yamnaya individuals and the same Central Anatolian Bronze Age samples, meaning that their shared ancestry is not limited to the CHG component. Besides the detectable steppe admixture, the IBD sharing between Steppe Eneolithic samples and Central Anatolian Bronze Age samples means that they become open to the possibility of a homeland north of the Caucasus. The route preferred by Lazaridis et al is that this CLV ancestry reached Anatolia by first moving through Armenia, where the Chalcolithic samples from Areni Cave show ancestry from north of the Caucasus, then moved into Anatolia after mixing with Mesopotamian-related populations.

Yamnaya and Anatolians share CLV ancestry (Fig. 2e,f), which must stem from proto-Indo-Anatolian language speakers, except for the possibility of an early transfer of language without admixture. That the CLV ancestry in Central Anatolians during the Hittite presence included lower Volga-related ancestry implies an origin north of the Caucasus (Fig. 2f and Extended Data Fig. 1). Long (30 cM or longer) IBD segments shared by Igren-8 Serednii Stih and Areni-1 with Berezhnovka-2 document Eneolithic links of lower Volga ancestry (Extended Data Table 5), and one link (15.2 cM) between the north Caucasus Vonyucka-1 with early Bronze Age Ovaören (MA2213) ties Central Anatolia to this once expansive network. Even so, only two Indo-Anatolian descendant groups transmitted their languages to posterity: the Yamnaya, aided by their horse-wagon technology, and Anatolian speakers, surviving long enough for their languages to be committed to clay around 2000 BC5, vanishing in late antiquity and fortuitously decyphered in the twentieth century. Our reconstruction, based on genetics (Extended Data Fig. 5), has traced both groups to the CLV people north of the Caucasus, but it cannot discern who first spoke pre-Indo-Anatolian languages.

[blazing_sun]

Thanks for the comprehensive answer.

Have any other Anatolian/South Caucasus samples been tested yet for this CLV cline? I remember reading about R1b-v1636 in Arslantepe, but that was discovered before this paper established CLV. Two of four samples at that site had steppe-related ancestry iirc.

[HurrianFam]

Thanks for the comprehensive answer.

Have any other Anatolian/South Caucasus samples been tested yet for this CLV cline? I remember reading about R1b-v1636 in Arslantepe, but that was discovered before this paper established CLV. Two of four samples at that site had steppe-related ancestry iirc.

I'm not sure I understand your question. This paper doesn't include any new samples from Anatolia or the South Caucasus, all the results I'm talking about regarding CLV ancestry in these regions is from running previously sampled individuals from this area through models that include the new samples from the North Caucasus and Steppe. 

Extended Data Fig.1: The steppe (BPgroup)+Çayönü model fails all Chalcolithic/Bronze Anatolians except people of the Central Anatolian Bronze Age. d, Steppe (BPgroup) ancestry in the BPgroup+Çayönü model is observed in all individuals of the Central Anatolian Bronze Age (mean and ±3 s.e. estimated by qpAdm are shown for all Chalcolithic and Bronze Age individuals from Anatolia that fit the model at p > 0.05) as well as in individual ART027_d from Chalcolithic Arslantepe in Eastern Anatolia. e, BPgroup-related ancestry admixed with different substrata: Aknashen-related in the North Caucasus Maikop, Masis Blur-related in Chalcolithic Armenia, and Mesopotamian-related (Çayönü) in the ancestors of the Central Anatolian Bronze Age, following the route (f) from the North Caucasus to Anatolia; sites with BPgroup-related ancestry marked in bold. In all panels p-values estimated by qpWave are shown.

   

[Jaska]

These two movements would produce very different languages, as different to one another as Core PIE is to Anatolian. They cannot be grouped under a single umbrella. "Oh these languages stayed similar, but Yamnaya differed more" is nonsensical.

Well, not necessarily nonsensical – it all comes back to the linguistic results. Which branch was more innovative, Anatolian or core Indo-European? If the latter, then “Proto-Anatolian” could almost equal Proto-Indo-Anatolian. In theory, we could have a tripartite division of Proto-Indo-Anatolian:

1. Western Indo-Anatolian
2. Eastern Indo-Anatolian
3. Northern Indo-Anatolian = Core/Late Proto-Indo-European

Then, the first two branches could have ended up in Anatolia via different routes converging there to form the reconstructed Proto-Anatolian, while their closest relatives in Europe became replaced by LPIE descendants.

Kloekhorst et al. 2023 (Proto-Indo-Anatolian, the “Anatolian split” and the “Anatolian trek”: a
comparative linguistic perspective) write:
“Recently, Tijmen Pronk and I have gathered a total of twenty-three examples that we regard as “good candidates” for possible linguistic innovations that have taken place between Proto-Indo-Anatolian and Classical Proto-Indo-European (Kloekhorst & Pronk 2019: 3–4). - - Besides these twenty-three cases, we list another eleven examples that we regard as “promising, though perhaps less forceful” than the other ones, or as “requiring additional investigation before it can be decided whether we are genuinely dealing with an innovation of the ‘classical’ Indo-European languages” (ibid.: 4–5). - - we would arrive at a date of ca. 4400 to 4200 BCE for the “Anatolian split,” which means that the last stage of Proto-Indo-Anatolian must have been spoken before this date.”

However, when we look at Proto-Anatolian itself, it seems to require an early “linguistic bottleneck” between 4200–3000 BCE, thus making it impossible that “Anatolian” languages could have arrived in Anatolia through two different routes and then converging there:

“Nevertheless, there are certain innovations in Proto-Anatolian that most scholars would agree on - - The changes in the verbal system in particular seem to be innovations that would have needed considerable time to take place. We may therefore assume that the time gap between Proto-Indo-Anatolian and Proto-Anatolian may have been at least 1000 years, or perhaps even 1200 years.”

However, even this still leaves a theoretical possibility for a tripartite division of Proto-Indo-Anatolian:

1. Proto-Anatolian (western or eastern route to Anatolia)
2. Extinct branch (the remaining route to Anatolia)
3. Northern branch = Core/Late Proto-Indo-European

Although it is very possible that there were also language lineages which have not survived and about which we do not even know anything, it is of course methodologically questionable to assume such language lineages based only on ancient DNA. Most movements of people were never accompanied by the spread of a new language (or at least the prevailing of such a new language in the target region after the first generation of immigrants).

And another thing often overlooked in linguistics is convergence. By the time records survive, the various Anatolian branches were already interacting in Anatolia for centuries. That might mess up textbooks ‘divergence by time’ clocks.

This is a valid point.
There is more than a millennium from Proto-Anatolian to the literarily attested Anatolian languages. Some shared features could be due to the convergence of closely related and geographically adjacent vernaculars after the actual proto-language. So, I rephrase:
"However, when we look at Proto-Anatolian itself, it seems to require an early “linguistic bottleneck” between 4200–3000 BCE, thus making it impossible that “Anatolian” languages could have arrived in Anatolia through two different routes and then converging there - unless these linguistic developments in reality occurred in a convergence process after Proto-Anatolian."

[parasar]

Thinking of making a map of early I-L699 samples (very rough draft below). It's not exhaustive, but any others that folks here think are worth including?

It appears that L699 goes down in frequency in the area almost at the same time as R1a goes up.
So it is quite possible that the movement to the Indus/Swat-Katelai region was from a population during this transition period.

"the Don Yamnaya, dominated by haplogroup I-L699 (17 of 20 instances), had continuity with their Serednii Stih and Neolithic hunter-gatherer ancestors (Fig.3 and Supplementary Table 7)" 
https://reich.hms.harvard.edu/sites/reic...Nature.pdf

"Haplogroup I-L699 was an important lineage in the Dnipro area since the Neolithic hunter-gatherer period, continued to be prevalent among the Serdenii Stih, and in the Don Yamnaya was dominant (17/20 instances)."

"Temporal distribution of key Y-chromosome haplogroups from Kazakhstan, Kyrgyzstan, Mongolia, Russia, Turkmenistan, Ukraine, Uzbekistan, and comparative regions of Europe and West Asia 6000–1000 BCE. The Early and Middle Bronze Age group includes the Yamnaya, Afanasievo, Poltavka, Catacomb, Chemurchek, and North Caucasus cultures; the Middle and Late Bronze Age group individuals of diverse cultures down to 1000 BCE including those of the Sintashta, Andronovo, Potapovka, and Srubnaya cultures."

[Rozenfeld]

I found this video on Youtube:


https://www.youtube.com/watch?v=JfDHfVJTfDA

Dr. Nick Patterson (Broad Institute) presents a guest lecture on how archaeogenetics, archaeology, and linguistics are uniting to answer the question of where Indo-European languages originated and how they spread, with questions and remarks from Prof. Tony Yates (UCLA) and Dr. Jackson Crawford.

I have not watched it myself yet

[AimSmall]

Nice find Rozenfeld

[RCO]

Here we go, again !

[Konieczny]

Dr. Nick Patterson, mentions Sintashta culture and the older culture Poltavka in regards to horse breeding. No word on the Catacomb culture horse burial around Tsatsa, Russia?

[parasar]

Here we go, again !