Showing posts with label Steppe. Show all posts
Showing posts with label Steppe. Show all posts

Wednesday, November 13, 2024

Steppe Eneolithic and the Origins of Yamnaya Ancestry

Steppe Eneolithic and the Origins of Yamnaya Ancestry

In 2019, Wang et al. published three ancient DNA samples from the northern Caucasus foothill steppe region. These samples were labeled Steppe Eneolithic. In genetic studies, the term “Steppe” is usually used to describe DNA profiles related or similar to the Yamnaya genetic profile.

These Steppe Eneolithic samples were remarkable because they already displayed a genetic profile similar to Yamnaya, while being older than the Yamnaya culture itself. At the time, however, they did not receive the attention they deserved, largely because they were not associated with a well-known archaeological culture.

In 2024, Lazaridis et al. proposed a new term for this population: the Caucasus–Lower Volga (CLV) cline, and added additional samples with similar genetic profiles. Genetic modeling showed that Yamnaya populations derived most of their genome-wide ancestry from these CLV groups.

Despite this important progress, two crucial Y-DNA markers were still not securely linked to the CLV population: R1b-M269 and R1a-M417, the two major lineages that later expanded widely across Eurasia and are often associated with the spread of Indo-European languages.

New Evidence

The study by Ghalichi et al. (2024) helped fill this gap. Two new cases of R1b-M269 were discovered north of the Caucasus, predating the Yamnaya culture. These individuals had ancestry similar to other Steppe Eneolithic groups and were dated to approximately 3800 BCE.

It is worth noting that an older R1b-M269 sample (I33307) from Kalmykia, dated to around 3700 BCE, had already been reported. However, its genetic profile is identical to Core Yamnaya, which raises the possibility that the radiocarbon date may be somewhat inaccurate. In Lazaridis et al., this sample was classified as part of the Russia_CaspianInland_EBA_Yamnaya group, which is why it is not included in the list of Steppe Eneolithic Y-DNA samples (4700–3000 BCE).
(See the map for the geographic area.)

Steppe Eneolithic Y-DNA Distribution (4700–3000 BCE)

  • R1b-V1636 — 9 samples

  • R1b-M269 — 2 samples

  • R1a — 1 sample

  • I2-L699 — 1 sample

  • J2a — 1 sample

  • J2b2a — 1 sample

Another possible early R1b-M269 case (around 4500 BCE) was discovered in a Varna culture burial in Bulgaria. Its autosomal profile clearly shows Steppe Eneolithic–related ancestry, indicating that it was not related to local Neolithic farmers but rather represents a migrant from the Caucasus–Lower Volga region.

The Varna culture itself was unusual, characterized by a highly hierarchical social structure. Its graves contained large quantities of gold artifacts, among the earliest known examples of gold metallurgy.

The Role of J2b2a-L283

Another important finding in the Steppe Eneolithic context is J2b2a-L283. Its autosomal profile shows a stronger Caucasus-related component, which is understandable. Nevertheless, it clearly belonged to the emerging Eneolithic kurgan populations, from which both the Yamnaya culture and the Corded Ware culture would develop several centuries later.

The Question of R1a-M417

So far, R1a-M417 has not yet been identified in the Steppe Eneolithic / CLV context. However, one of the oldest R1a-M198 samples (closely related to M417) was found in the Middle Volga region, suggesting that M417 may eventually be discovered within the CLV or Steppe Eneolithic populations as well. Currently, one of the oldest known R1a-M417 individuals comes from a Yamnaya layer in the Balkans.

Implications for Yamnaya Origins

Based on these findings, I remain skeptical of the hypothesis that Yamnaya originated directly from the Sredny Stog culture in Ukraine, as sometimes suggested in discussions.

The highest diversity of R1b-Z2103 lineages that are positive for Z2103 but negative for Z2106 is found in the Near East, suggesting that the region where Z2103 began its expansion was likely close to the Caucasus. Additional ancient DNA samples will hopefully clarify this question in the future.

Note

The Eneolithic Y-DNA list above does not include samples from Steppe Maykop, which have a different origin related to Central Asian ancestry.

In addition, one R1b-V1636 sample is dated to around 2800 BCE, slightly later than the 3000 BCE cutoff used here. However, its autosomal profile indicates that it belonged to the preceding Steppe Eneolithic population, rather than to Core Yamnaya.

Sunday, November 3, 2024

Ukraine Neolithic Hunter-Gatherer Ancestry in Yamnaya

Ukraine Neolithic Hunter-Gatherer Ancestry in Yamnaya

Lazaridis et al. (2024) discovered that Yamnaya populations contain a component of Ukraine Neolithic hunter-gatherer ancestry (UNHG). The term UNHG can be somewhat confusing, since in some archaeological traditions—especially in former Soviet scholarship—a hunter-gatherer community may be labeled “Neolithic” simply because it produced pottery, even if it did not practice farming.

Ghalichi et al. (2024) confirmed the presence of roughly 15% UNHG ancestry in Yamnaya populations. One example of a lineage associated with this component is I2-L699, which is regularly found in steppe populations and appears to derive from UNHG groups.

Importance for Armenian Ethnogenesis

The presence of I2 lineages in Yamnaya-related cultures is particularly relevant for discussions of Armenian ethnogenesis, given the presence of I2a2b in the Trialeti–Vanadzor culture.

Until recently, we had little additional information about this lineage. The closest European sample related to it was found in Eneolithic Croatia, with a common ancestor dated by FTDNA to around 8200 BCE. This age is sufficiently early for the lineage to have existed both among European farmers and UNHG populations.

A New Clue from the Steppe Eneolithic

Ghalichi et al. (2024) reported a new sample that may shed light on how I2a2b could have entered early Yamnaya communities as a rare lineage.

The study includes a female individual from the region near the Azov–Black Sea junction, labeled “Steppe Eneolithic outlier west” (KHB) and dated to around 4000 BCE near the Taman Peninsula. This individual shows a very high proportion of UNHG ancestry (about 43%), suggesting that the population may have migrated into the region from Ukraine.

Possible Scenario

If this outlier represents a regular population present in the region, it raises the possibility that I2a2b-Y16419 was also present there during the Eneolithic period. When Yamnaya and later Catacomb cultures formed, this lineage may have been incorporated into those populations as a minor component.

Later, it may have moved southward, eventually becoming part of populations associated with the Trialeti–Vanadzor culture, where it experienced a more significant expansion.

Future Research

To verify this hypothesis, additional ancient DNA samples will be necessary, particularly from:

  • the Azov–Taman region, and

  • southern Ukraine more broadly.

Such data may help clarify how UNHG-derived lineages became integrated into steppe populations and later appeared in the South Caucasus.



Saturday, May 18, 2024

Qpadm models about the Core Yamnaya origins.

We have one sample from north Caucasus PG2004 which is similar to so called BP group of Caucasus Lower Volga cline.

Modeling Yamnaya as a three-way mixture of CLV_BP, Aknashen and Ukraine Neolithic hunter gatherers was very easy, as in the paper.
BP group 66.5%
Aknashen 19.5%
UNHG. 14.0%
p value 0.17
It didn't require from me any extra effort to find the correct "settings" (outgroups). Adding western Ukraine Trypllia farmers didn't made the model better. Aknashen was still wanted while Trypllia not. I tried various ways to make Trypllia wanted, but it didn't work. Finally, I removed Aknashen and forced the model to rely solely in Trypllia. I got a p value lower than 0.05. So practically a failure. Nikitin 2024 dedicates a special chapter to this subject. Their conclusion is that Yamnaya probably do have some Trypllia but it's very low.
My conclusions are the same. Aknashen ancestry in Yamnaya is real. It is supported by Y DNA of preceding period, and I am sure that the scrupulous analysis of mtDNA will show the same result. Finally, if I had access to the Nalchik farmer data then the percentage would be twice higher.
Then I tried the same in G25 and here a surprise. The raw unscaled models behaved in the same manner as qpadm albeit with a different proportion. But the scaled G25 showed a clear a preference for Trypllia. I said in this group many times that tools and settings matters. And this an excellent example why the use of scaled models can lead to misleading results. I want to remind that scaled coordinates are artificially altered numbers.
Keeping this in mind let's see what means CLV-steppe ancestry in Bronze Age Anatolia that Lazaridis 2024 supposedly has found but Lazaridis 2022 didn't detected. I don't have Cayonu files to reproduce their models in qpadm but what we know from G25 behavior is that:
+ When Anatolia N and CHG are used in models as source they mask the steppe ancestry and show a lower number. This was done in Lazaridis 2022 which not only didn't find any steppe in BA Anatolia but even in Van Urartu.
+ When a Mesopotamian or Levantine and Iran Neo are used as sources and CHG and Anatolia_N are ommitted then this exaggerates the steppe ancestry in northwest Asia. In Lazaridis 2024 they used Cayonu Neolithic which was a north Mesopotamian population. This exaggerated the steppe ancestry in Bronze Age Anatolia where Hittite lived. If the same Cayonu was used for Minoans, they would find steppe even in Minoans and probably Alalakh Hurrians and Semites also. Which doesn't make sense. Uniparental markers do NOT support such high level of CLV-steppe ancestry in BA Anatolia. Quite contrary they speak about very low or virtual absence of it. Just one R1b-V1636 in the midst of more than dozen local haplotypes.
My conclusions are that based on this genetic data it is not possible to consider IE homeland issue fully solved. We are very close it. And the broad picture. But the exact details are not still there, and linguistics also can be helpful.
What is needed now is to have more than 50 Y DNA from Bronze Age Anatolia. Also, a large number of Y DNA is needed from South Caucasus and historic Armenia LC-EBA period to see what happened to those Late Chalcolithic migrants from north. How much they left an impact and why their autosomes were diluted after the Areni C. It is also important to have samples from LC kurganic burials like Aknalich and Soyuq Bulaq.

See also








Saturday, April 27, 2024

Pastoralism in East Europe

We have now quite large number of samples before the Yamnaya period in East Europe ( before 3300BC) to have some conclusions about the origins of pastoralism in Pontic Caspian steppe and forest steppe regions.

If we keep aside local hunter gatherer lineages and those associated with Maykop culture in North Caucasus, then we are left with haplotypes that are associated with South Caucasian farmers. Shulaveri Aratashen culture.
  • J2-M319 - an obvious farmer lineage, which usually is associated with Minoans but it's deeper origins are without doubt in historic Armenia. Absent in European farmers.
  • J2b2b from Eneolithic Moldova associated with migrations from east. This branch was never found in any Euro-Anatolian farmer site but was found in Mentesh tepe in northwest of Azerbaijan.
  • J2b2a1-L283 currently the oldest sample from this branch is from Yamnaya but there is little doubt that it was present in Eneolithic steppe also. It became part of Yamnaya communities, moved to west Balkans and had a successful founder effect there. It's parallel branch the J2b2a2 is a lineage found in farmers from Central Asia who from there moved to India. Thus, indirect evidence supports that it was a south Caucasian farmer lineage. Its hunter gatherer origin is less likely.
  • J1b - it was a west Caucasian hunter lineage. It could be a CHG lineage in steppe. But a farmer lineage can't be ruled out completely given that this branch was found in many farmers sites stretched from Pakistan to Crete. In steppe it was found in Volga region and Usatovo cultures.
  • J1-CTS1026 - similar to J1b uncertain affiliation. It's south Caucasian origin in steppe is without doubt.
Besides those cases there were also J1* in Karelia in hunter gatherer context. Those were almost certainly from CHG.
On the other hand, there was no single European farmers lineage found in Pontic Caspian steppe. Archaeologists believed that west Ukraine farmers played an important role in the introduction of pastoralism, but the genetic data do not support that idea. In west Ukraine Cucuteni Trypllia farmers we have G2a2a, G2a2b, E1b-L618, C1a2, I2a2a etc. None of them is found in steppe.
An unpublished sample from Nalchik proves that farmers from South Caucasus moved to north. Despite this southern input, the Eneolithic steppe was predominantly R1b-V1636 and I2-L699. This latter was a Ukraine hunter gatherer lineage in its deep origin.
What was the reason of the mismatch between autosomes and Y DNA is hard to say but a similar scenario occurred in main Europe where after an initial success, the G2 farmers lost their positions and I2 became more frequent. While the autosomes didn't change in a significant manner.
Those genetic results is supported by the linguistics data also. Sahala notice that the Sumerian word gud, gu meaning ox, bull is a good parallel with PIE *gou(s) meaning cow, ox. From which the Armenian word kov is derived.
Matasovic notice that the reconstructed PIE language morphology shares features with North Caucasian languages.
PS You can see the Caucasus Lower Volga cline on the map which had both CHG and South Caucasian farmers ancestry mixed with local hunter gatherers



Friday, April 26, 2024

The Yamnaya culture and it's legacy

Yamnaya was an Early Bronze Age culture (3300-2700BC) that expanded in Pontic Caspian steppe in East Europe. It is remarkable due to its homogenous population which contrasts to the diversity of the preceding Eneolithic (means Chalcolithic) cultures. In just 1000 years genes associated with Yamnaya culture reached what is now Portugal and western Mongolia, Britain and South-Central Asia. The scale of this expansion can be considered as one of the most important demographic events in West Eurasia after the invention of farming in Fertile Crescent. In 2022 Lazaridis et al. announced that all modern living IE nations languages can be derived from the Yamnaya.
In 2015 the first ancient DNA of Yamnayans was published and it became clear that they do not directly descend from Eastern European hunter gatherers. Roughly the half of their ancestry was from south, and the "Armenian like" term was used to label this southern part. Then in late 2015 the Caucasian hunter gatherers (CHG) were discovered. In 2016 Iranian Zagros Neolithic farmers were published and since then both those populations were used to model the Yamnayans.
Despite those statistical models the formation of Yamnayans gene pool was remaining an obscure subject. Finally in April 2024 two large papers dedicated to this subject provided more clarity. Various Neolithic and Eneolithic groups living in East Europe had both shared ancestry and differences. One group who was living from North Caucasus foothills to Lower Volga (site Berezhnovka ) was labeled as "Caucasus Lower Volga cline". CLV had both southern Caucasian hunters and farmers (Aknashen) ancestry.
I will dedicate a special topic to describe what is CLV but at this stage it's sufficient to say that Yamnayans had up to 80% of their ancestry from CLV. Not only Yamnayans but all Kurganic cultures (Sredni Stog, Khvalynsk, Cernabida, Usatovo) of eastern Europe and Balkans had the CLV ancestry mixed with various local European populations. For the case of Yamnayans the second part of their ancestry was the Ukraine hunter gatherers (UNHG), which made them similar to Sredni Stog. Even though the most important Y DNA's were missing in Sredni Stog which could mean that Proto Yamnaya's exact immediate geographic location is not found yet but shouldn't be outside from Don - Volga - Caucasus triangle. With more sampling we will learn the exact origin of the two most successful lineages. R1b-M269 and R1a-M417.
The samples from the new paper are not available yet but we have two samples from the forementioned CLV cline. They are from the Progress - 2 site in the North Caucasus (4500-4000BC, see the last map for the location). I used them to model various Yamnaya samples and got the same result as in Lazaridis 2024. More than 75-80% of ancestry in regular Yamnaya samples is from the Progress / CLV. Some outliers have extra ancestries which is normal given their location.
You may wonder how "Hittites from east, from historic Armenia" and "Yamnaya from CLV" are connected to each other? After all there is no evidence that Hittites and other Anatolian speakers descend from Yamnaya culture. What is the common shared ancestry between IE Anatolians and Yamnaya?
Another topic will be dedicated to this subject.
And at the end here is the list of Y DNA found in Yamnaya at this stage. R1b-Z2103 (west Asia Balkans), R1b-L51 (west Europe), R1a-M417 (Asia - Europe), I2-L699, J2b-L283 (west Balkans), R1b-PF7562 (Balkans Mycenean ) Q-L939 and isolated cases of J1 and R1b-V1636.

See also






Wednesday, October 25, 2023

There is some big data that is accumulating about the Upper Paleolithic period in Caucasus and Europe

There is some big data that is accumulating about the Upper Paleolithic period in Caucasus and Europe. We have 26000-year-old samples from West Georgia and now very important samples from Crimea. (~36000-year-old, Bennet 2023).

This samples from Crimea can be labeled as Proto Gravettian culture. The Gravettian culture is very important for Europe because their autosomes are at the origin of later WHG that appears after the LGM. Gravettian culture is also important because it's the first apparition of the haplogroup I in Europe which later will expand in the form of I2.
With this new data it's becoming clear that the population that created the Gravettian culture moved via Caucasus to Eastern Europe and from there to Balkans and Western Europe. Replacing the local more archaic humans, who left virtually no ancestry in modern Europeans.
This make sense from the Y DNA point of view because I and J have common ancestors and the oldest cases of J are found in Southern Caucasus.
Based on the Yfull the I and J separated from each other 42000 years ago. Which is consistent with the archaeological dates we have.
And finally, the Upper Paleolithic samples from Western Georgia are very unusual. They are quite different from post-LGM period Caucasian hunter-gathers (CHG). Those Caucasian Upper Paleolithic samples have lot shared alleles with Anatolian hunter gatherers and farmers. But even more surprising they had shared alleles with WHG that didn't exist yet at that period. Also, they had shared alleles with Eastern European Upper Paleolithic samples like Kostenki14 and Vestonice cluster, the aforementioned Gravettian culture.
This situation make sense given the common origins of J and I. We could expect that in the deep past they were coming from a population with similar autosomes.
Below in Figure 1 You can see the closest pops to Georgia Upper Paleolithic. As You can see it's more oriented to ancient Europe with high Anatolian and WHG ancestries.
The next puzzle now to solve is the origin of CHG and Iran_Neo. What made them so different from Anatolia forager's/farmers. And the ultimate question where the common origin of all these folks was.