Western Steppe Herders

In archaeogenetics, the term Western Steppe Herders (WSH), or Western Steppe Pastoralists, is the name given to a distinct ancestral component that represents descent closely related to the Yamnaya culture of the Pontic-Caspian steppe.[lower-alpha 1] This ancestry is often referred to as Yamnaya Ancestry, Yamnaya-Related Ancestry, Steppe Ancestry or Steppe-Related Ancestry.[4]

Scheme of Indo-European migrations from c. 4000 to 1000 BCE according to the widely held Kurgan hypothesis. These migrations are thought to have spread WSH ancestry and Indo-European languages throughout large parts of Eurasia.[1][2][3]

WSHs are considered descended from Eastern Hunter-Gatherers (EHGs) who received some admixture from Caucasian Hunter-Gatherers (CHGs) during the Neolithic. The Y-DNA of the WSHs was mostly types of R1a and R1b, which are EHG lineages, suggesting that CHG admixture among the WSHs came through EHG males mixing with CHG females.[5] Around 3,000 BC, people of the Yamnaya culture, who belonged to the WSH cluster, embarked on a massive expansion throughout Eurasia, which might have resulted in the dispersal of Indo-European languages. WSH ancestry from this period is often referred to as Steppe Early and Middle Bronze Age (Steppe EMBA) ancestry.[lower-alpha 2]

This expansion led to the rise of the Corded Ware culture, whose members were of about 75% WSH ancestry, and the virtual disappearance of the Y-DNA of Early European Farmers (EEFs) from the European gene pool, significantly altering the cultural and genetic landscape of Europe. During the Bronze Age, Corded Ware people with admixture from Central Europe remigrated onto the steppe, forming a type of WSH ancestry often referred to as Steppe Middle and Late Bronze Age (Steppe MLBA) ancestry.[lower-alpha 2] Through the Sintashta culture, Andronovo culture and Srubnaya culture, Steppe MLBA was carried into Central Asia and South Asia along with Indo-Iranian languages, leaving a long-lasting cultural and genetic legacy.

The modern population of Europe can largely be modeled as a mixture of WHG (Western Hunter-Gatherer), EEF and WSH. In Europe, WSH ancestry peaks among Norwegians (ca. 50%), while in South Asia, it peaks among the Kalash people (ca. 50%) and Brahmins, according to Lazaridis et al. (2016). Narasimhan et al (2019), which employed a wider range of references in their ancestry models, found lower levels of steppe-derived ancestry among modern South Asians (e.g. ~30% among the Kalash).

Summary

Migration of Yamnaya-related people, according to Anthony (2007),[6] 2017;[7][note 1] Narasimhan et al. (2019);[8] Nordqvist and Heyd (2020):[9]
* 3000 BC: Initial eastward migration initiating the Afanasievo culture, possibly Proto-Tocharian.
* 2900 BC: North-westward migrations carrying Corded Ware culture, transforming into Bell Beaker; according to Anthony, westward migration west of Carpatians into Hungary as Yamnaya, transforming into Bell Beaker, possibly ancestral to Indo-Celtic (disputed).
* 2700 BC: Second eastward migration starting east of Carpatian mountains as Corded Ware, transforming into Fatyanovo-Balanova (2800 BCE) -> Abashevo (2200 BCE)-> Sintashta (2100-1900 BCE)-> Andronovo (1900-1700 BCE) -> Indo-Aryans.

A summary of several genetic studies published in Nature and Cell during the year 2015 is given by Heyd (2017):

Western Steppe Herders component "is lower in southern Europe and higher in northern Europe", where it is shared by more than 50 per cent of the current inhabitants of Norway, Lithuania and Estonia (Haak et al. 2015);
It is linked to the migrations of Yamnaya populations dated to ca. 3000 BCE (Allentoft et al. 2015; Haak et al. 2015);
Genetic transmission passed from steppe Yamnaya directly to the Corded Ware–Single Grave–Battle Axe Complex (Haak et al. 2015);
Third-millennium Europe (and prehistoric Europe in general) was "a highly dynamic period involving large-scale population migrations and replacement" (Allentoft et al. 2015);
The Yamnaya migrations are linked to the spread of Indo-European languages (Allentoft et al. 2015; Haak et al. 2015);
The plague (Yersinia pestis) killed prehistoric humans in Europe during the third millennium BCE (Rasmussen et al. 2015), and it stemmed from the Eurasian steppes;
Yamnaya peoples have the highest ever calculated genetic selection for stature (Mathieson et al. 2015);
Yamnaya peoples were light-skinned but had dark eye colours; blue eyes were more common in the Corded Ware–Single Grave–Battle Axe Complex, but the lactase persistence mutation was not yet present (Allentoft et al. 2015).

Studies

Haak et al (2015), Massive migration from the steppe was a source for Indo-European languages in Europe

Haak et al. (2015), Massive migration from the steppe was a source for Indo-European languages in Europe, a ground-breaking study published in Nature, found the ancestry of the people of the Yamnaya culture to be a mix of Eastern Hunter-Gatherer and another unidentified population. All seven Yamnaya males surveyed were found to belong to subclade R-M269 of haplogroup R1b. R1b had earlier been detected among EHGs living further north.[1]

The study found that people of the Corded Ware culture were of approximately 75% WSH ancestry, being descended from Yamnaya people who had mixed with Middle Neolithic Europeans. This suggested that the Yamnaya people embarked on a massive expansion ca. 3,000 BC, which might have played a role in the dispersal of Indo-European languages in Europe. At this time, Y-DNA haplogroups common among Early European Farmers (EEFs), such as G2a, disappear almost entirely in Central Europe, and is replaced by haplotypes of R1b and R1a, which are common among WSH. EEF mtDNA decreases significantly as well, and is replaced by WSH types, suggesting that the Yamnaya expansion was carried out by both males and females. In the aftermath of the Yamnaya expansion there appears to have been a resurgence of EEF and Western Hunter-Gatherer (WHG) ancestry in Central Europe, as this is detected in samples from the Bell Beaker culture and its successor the Unetice culture.[1] The Bell Beaker culture had about 50% WSH ancestry.[10]

All modern European populations can be modeled as a mixture of WHG, EEF and WSH. WSH ancestry is more common in Northern Europe than Southern Europe. Of modern populations surveyed in the study, Norwegians were found to have the largest amount of WSH ancestry, which among them exceeded 50%.[1]

Allentoft et al. (2015), Population genomics of Bronze Age Eurasia

Allentoft et al. (2015), Population genomics of Bronze Age Eurasia, published in Nature in June 2015 examined the Y-DNA of five Yamnaya males. Four belonged to types of R1b1a2, while one belonged to I2a2a1b1b. The study found that the Neolithic farmers of Central Europe had been "largely replaced" by Yamnaya people around 3,000 BC. This replacement altered not only the genetic landscape, but also the cultural landscape of Europe in many respects.[11]

It was discovered that the people of the contemporary Afanasievo culture of southern Siberia were "genetically indistinguishable" from the Yamnaya and thus largely of WSH ancestry. People of the Corded Ware culture, the Bell Beaker culture, the Unetice culture and the Nordic Bronze Age displayed close genetic affinity to WSH. The authors of the study suggested that the Sintashta culture of Central Asia emerged as a result of an eastward migration from Central Europe of Corded Ware people with both WSH and European Neolithic farmer ancestry.[11]

Jones et al. (2015), Upper Palaeolithic genomes reveal deep roots of modern Eurasians

Jones et al. (2015), Upper Palaeolithic genomes reveal deep roots of modern Eurasians, published in Nature Communications in November 2015, found that the WSHs were descended from admixture between EHGs and Caucasian Hunter-Gatherers (CHGs). CHGs were found to have split off from WHGs ca. 43,000 BC, and to have split off from EEFs ca. 23,000 BC.[12]

Mathieson et al. (2015), Genome-wide patterns of selection in 230 ancient Eurasians

Mathieson et al. (2015), Genome-wide patterns of selection in 230 ancient Eurasians, published in Nature in November 2015 found that the people of the Poltavka culture, Potapovka culture and Srubnaya culture were closely related and largely of WSH descent, although the Srubnaya carried more EEF ancestry (about 17%) than the rest. Like in Yamnaya, males of Poltavka mostly carried types of R1b, while Srubnaya males carried types of R1a.(Mathieson et al. 2015)

The study found that most modern Europeans could be modelled as a mixture between WHG, EEF and WSH.[lower-alpha 3]

Genomic insights into the origin of farming in the ancient Near East

A genetic study published in Nature in July 2016 found that WSHs were a mixture of EHGs and "a population related to people of the Iran Chalcolithic". EHGs were modeled as being of 75% Ancient North Eurasian (ANE) descent. A significant presence of WSH ancestry among populations of South Asia was detected. Here WSH ancestry peaked at 50% among the Kalash people, which is a level similar to modern populations of Northern Europe.[13]

Genetic Origins of the Minoans and Mycenaeans

A genetic study published in Nature in August 2017 examined the genetic origins of the Mycenaeans and the Minoans. Contrary to the Minoans, the Mycenaeans were found to harbor about 15% WSH ancestry. It was found that Mycenaeans could be modelled as a mixture of WSH and Minoan ancestry. This suggests that the Mycenaeans arrived in Greece as a southern wing of the Indo-European migrations.[14]

The Beaker phenomenon and the genomic transformation of northwest Europe

A genetic study published in Nature in February 2018 examined the entry of WSH ancestry into the British Isles. WSH ancestry was found to have been carried into the British Isles by the Bell Beaker culture in the 3rd millennium BC. The migrations of Bell Beakers were accompanied with "a replacement of ~90% of Britain's gene pool within a few hundred years". The gene pool in the British Isles had previously been dominated by EEFs with slight WHG admixture.[lower-alpha 4]

Y-DNA in parts of the modern British Isles belongs almost entirely to R-M269, a WSH lineage, which is thought to have been brought to the isles with Bell Beakers.[15]

The Genomic History of Southeastern Europe

A genetic study published in Nature in February 2018 noted that the modern population of Europe can largely be modeled as a mixture between EHG, WHG, WSH and EEF.[lower-alpha 5]

The study examined individuals from the Globular Amphora culture, who bordered the Yamnaya. Globular Amphora culture people were found to have no WSH ancestry, suggesting that cultural differences and genetic differences were connected.[10]

Notably, WSH ancestry was detected among two individuals buried in modern-day Bulgaria ca. 4,500 BC. This showed that WSH ancestry appeared outside of the steppe 2,000 years earlier than previously believed.[10]

The First Horse Herders and the Impact of Early Bronze Age Steppe Expansions into Asia

Damgaard et al. 2018 found that that Yamnaya-related migrations had a lower direct and long-lasting impact in East and South Asia than in Europe. Crucially, the Botai culture of Late Neolithic Central Asia was found to have no WSH ancestry, suggesting that they belonged to an ANE-derived population deeply diverged from the WSHs.[16]

Bronze Age population dynamics and the rise of dairy pastoralism on the eastern Eurasian steppe

A genetic study published in the Proceedings of the National Academy of Sciences of the United States of America in November 2018 examined the presence of WSH ancestry in the Mongolian Plateau. A number of remains from Late Bronze Age individuals buried around Lake Baikal were studied. These individuals had only 7% WSH ancestry, suggesting that pastoralism was adopted on the Eastern Steppe through cultural transmission rather than genetic displacement.[2]

The study found that WSH ancestry found among Late Bronze Age populations of the south Siberia such as the Karasuk culture was transmitted through the Andronovo culture rather than the earlier Afanasievo culture, whose genetic legacy in the region by this time was virtually non-existent.[2]

Ancient Human Genome-Wide Data From a 3000-Year Interval in the Caucasus Corresponds with Eco-Geographic Regions

A genetic study published in Nature Communications in February 2019 compared the genetic origins of the Yamnaya culture and the Maikop culture. It found that most of the EEF ancestry found among the Yamnaya culture was derived from the Globular Amphora culture and the Cucuteni–Trypillia culture of Eastern Europe.[17][18] Total EEF ancestry among the Yamnaya has been estimated at 10-18%. Given the high amount of EEF ancestry in the Maikop culture, this makes it impossible for the Maikop culture to have been a major source of CHG ancestry among the WSHs. Admixture from the CHGs into the WSHs must thus have happened at an earlier date.[18]

The genomic history of the Iberian Peninsula over the past 8000 years

A genetic study published in Science in March 2019 analyzed the process by which WSH ancestry entered the Iberian Peninsula. The earliest evidence of WSH ancestry there was found from an individual living in Iberia in 2,200 BC in close proximity with native populations. By 2,000 BC, the native Y-DNA of Iberia (H, G2 and I2) had been almost entirely replaced with a single WSH lineage, R-M269. mtDNA in Iberia at this time was however still mostly of native origin, affirming that the entry of WSH ancestry in Iberia was primarily male-driven.[lower-alpha 6]

Narasimhan et al. (2019), The Genomic Formation of South and Central Asia

Yamnaya-related migrations according to Narasimhan et al. (2019).

Narasimhan et al (2019), The Genomic Formation of South and Central Asia, published in Science in September 2019, found a large amount of WSH ancestry among Indo-European-speaking populations throughout Eurasia. This lent support to the theory that the Yamnaya people were Indo-European-speaking.[3]

The study found people of the Corded Ware, Srubnaya, Sintashta and Andronovo cultures to be a closely related group almost wholly of WSH ancestry, but with slight European Middle Neolithic admixture. These results further underpinned the notion that the Sintashta culture emerged as an eastward migration of Corded Ware peoples with mostly WSH ancestry back into the steppe. Among early WSHs, R1b is the most common Y-DNA lineage, while R1a (particularly R1a1a1b2) is common among later groups of Central Asia, such as Andronovo and Srubnaya.[3]

West Siberian Hunter-Gatherers (WSGs), a distinct archaeogenetic lineage, was discovered in the study. These were found to be of about 30% EHG ancestry, 50% ANE ancestry, and 20% East Asian ancestry. It was noticed that WSHs during their expansion towards the east gained a slight (ca. 8%) admixture from WSGs.[3]

It was found that there was a significant infusion of WSH ancestry into Central Asia and South Asia during the Bronze Age. WSH ancestry was found to have been almost completely absent from earlier samples in southern Central Asia in the 3rd millennium BC.[lower-alpha 7]

During the expansion of WSHs from Central Asia towards South Asia in the Bronze Age, an increase in South Asian agriculturalist ancestry among WSHs was noticed. Among South Asian populations, WSH ancestry is particularly high among Brahmins and Bhumihars. WSH ancestry was thus expected to have spread into India with the Vedic culture.[3]

Antonio et al.(2019), Ancient Rome: A genetic crossroads of Europe and the Mediterranean

Antonio et al.(2019), Ancient Rome: A genetic crossroads of Europe and the Mediterranean, published in Science in November 2019 examined the remains of six Latin males buried near Rome between 900 BC and 200 BC. They carried the paternal haplogroups R-M269, T-L208, R-311, R-PF7589 and R-P312 (two samples), and the maternal haplogroups H1aj1a, T2c1f, H2a, U4a1a, H11a and H10. A female from the preceding Proto-Villanovan culture carried the maternal haplogroups U5a2b.[20] These examined individuals were distinguished from preceding populations of Italy by the presence of ca. 30-40% steppe ancestry.[21] Genetic differences between the examined Latins and the Etruscans were found to be insignificant.[22]

Fernandes et al. (2019), The Arrival of Steppe and Iranian Related Ancestry in the Islands of the Western Mediterranean

Fernandes et al. (2019), The Arrival of Steppe and Iranian Related Ancestry in the Islands of the Western Mediterranean, found that a skeleton excavated from the Balearic islands (dating to ∼2400 BCE) had substantial WSH ancestry; however, later Balearic individuals had less Steppe heritage reflecting geographic heterogeneity or immigration from groups with more European first farmer-related ancestry. In Sicily, WSH ancestry arrived by ∼2200 BCE and likely came at least in part from Spain. 4 of the 5 Early Bronze Age Sicilian males had Steppe-associated Y-haplogroup R1b1a1a2a1a2 (R-P312). Two of these were Y-haplogroup R1b1a1a2a1a2a1 (Z195) which today is largely restricted to Iberia and has been hypothesized to have originated there 2500-2000 BCE. In Sardinia, no convincing evidence of WSH ancestry in the Bronze Age has been found, but the authors detect it by ∼200-700 CE..[23]

Analysis

The American archaeologist David W. Anthony (2019) analyzed the recent genetic data on WSHs. Anthony notes that WSHs display genetic continuity between the paternal lineages of the Dnieper-Donets culture and the Yamnaya culture, as the males of both cultures have been found to have been mostly carriers of R1b, and to a lesser extent I2.[10]

While the mtDNA of the Dnieper-Donets people is exclusively types of U, which is associated with EHGs and WHGs, the mtDNA of the Yamnaya also includes types frequent among CHGs and EEFs. Anthony notes that WSH had earlier been found among the Sredny Stog culture and the Khvalynsk culture, who preceded the Yamnaya culture on the Pontic–Caspian steppe. The Sredny Stog were mostly WSH with slight EEF admixture, while the Khvalynsk living further east were purely WSH. Anthony also notes that unlike their Khvalynsk predecessors, the Y-DNA of the Yamnaya is exclusively EHG and WHG. This implies that the leading clans of the Yamnaya were of EHG and WHG origin.[24] Because the slight EEF ancestry of the WSHs has been found to be derived from Central Europe, and because there is no CHG Y-DNA detected among the Yamnaya, Anthony notes that it is impossible for the Maikop culture to have contributed much to the culture or CHG ancestry of the WSHs. Anthony suggests that admixture between EHGs and CHGs first occurred on the eastern Pontic-Caspian steppe around 5,000 BC, while admixture with EEFs happened in the southern parts of the Pontic-Caspian steppe sometime later.[5]

As Yamnaya Y-DNA is exclusively of the EHG and WHG type, Anthony notes that the admixture must have occurred between EHG and WHG males, and CHG and EEF females. Anthony cites this as additional evidence that the Indo-European languages were initially spoken among EHGs living in Eastern Europe. On this basis, Anthony concludes that the Indo-European languages which the WSHs brought with them were initially the result of "a dominant language spoken by EHGs that absorbed Caucasus-like elements in phonology, morphology, and lexicon" (spoken by CHGs).[5]

Physical appearance

Physical anthropologists have determined that the Yamnaya people and their successors were tall, massively built and Europoid.[25] This has been confirmed by genetic studies of WSHs, who are found to have been much taller than Neolithic populations of Central Europe. The genetic basis of a number of physical features of the Yamnaya people were ascertained by the ancient DNA (aDNA) studies conducted by Haak et al. (2015), Wilde et al. (2014) and Mathieson et al. (2015): They were genetically tall (phenotypic height is determined by both genetics and environmental factors), overwhelmingly dark-eyed (brown), dark-haired and had a skin colour that was moderately light, though somewhat darker than that of the average modern European. Despite their pastoral lifestyle, there was little evidence of lactase persistence. It has been suggested that the increased height of modern populations of Northern Europe as compared to those of Southern Europe can be ascribed to increased WSH ancestry among Northern Europeans.[lower-alpha 8]

Notes

"Recent paleogenomic studies have shown that migrations of Western steppe herders (WSH) beginning in the Eneolithic (ca. 3300–2700 BCE) profoundly transformed the genes and cultures of Europe and central Asia... The migration of these Western steppe herders (WSH), with the Yamnaya horizon (ca. 3300–2700 BCE) as their earliest representative, contributed not only to the European Corded Ware culture (ca. 2500–2200 BCE) but also to steppe cultures located between the Caspian Sea and the Altai-Sayan mountain region, such as the Afanasievo (ca. 3300–2500 BCE) and later Sintashta (2100–1800 BCE) and Andronovo (1800–1300 BCE) cultures."[2]
"We collectively refer to as "Western Steppe Herders (WSH)": the earlier populations associated with the Yamnaya and Afanasievo cultures (often called "steppe Early and Middle Bronze Age"; "steppe_EMBA") and the later ones associated with many cultures such as Potapovka, Sintashta, Srubnaya and Andronovo to name a few (often called "steppe Middle and Late Bronze Age"; "steppe_MLBA")."[4]
"Most present-day Europeans can be modeled as a mixture of three ancient populations related to Mesolithic hunter-gatherers (WHG), early farmers (EEF) and steppe pastoralists (Yamnaya)."(Mathieson et al. 2015)
"[M]igration played a key role in the further dissemination of the Beaker Complex, a phenomenon we document most clearly in Britain, where the spread of the Beaker Complex introduced high levels of Steppe-related ancestry and was associated with a replacement of ~90% of Britain's gene pool within a few hundred years."[15]
"It has previously been shown that the great majority of European ancestry derives from three distinct sources. First, "hunter-gatherer-related" ancestry that is more closely related to Mesolithic hunter-gatherers from Europe than to any other population, and can be further subdivided into "Eastern" (EHG) and "Western" (WHG) hunter-gatherer-related ancestry.7 Second, "NW Anatolian Neolithic-related" ancestry related to the Neolithic farmers of northwest Anatolia and tightly linked to the appearance of agriculture. The third source, "steppe-related" ancestry, appears in Western Europe during the Late Neolithic to Bronze Age transition and is ultimately derived from a population related to Yamnaya steppe pastoralists. Steppe-related ancestry itself can be modeled as a mixture of EHG-related ancestry, and ancestry related to Upper Palaeolithic hunter-gatherers of the Caucasus (CHG) and the first farmers of northern Iran."[10]
"We reveal sporadic contacts between Iberia and North Africa by ~2500 BCE, and by ~2000 BCE the replacement of 40% of Iberia's ancestry and nearly 100% of its Y-chromosomes by people with Steppe ancestry... Y-chromosome turnover was even more dramatic, as the lineages common in Copper Age Iberia (I2, G2, H) were nearly completely replaced by one lineage, R1b-M269."[19]
"Importantly, in the 3rd millennium BCE we do not find any individuals with ancestry derived from Yamnaya-related Steppe pastoralists in Turan. Thus, Steppe_EMBA ancestry was not yet widespread across the region."[3]
"[R]esults suggest that the modern South-North gradient in height across Europe is due to both increased steppe ancestry in northern populations, and selection for decreased height in Early Neolithic migrants to southern Europe."(Mathieson et al. 2015)

See also Eurogenes Blog (December 18, 2017), Corded Ware as an offshoot of Hungarian Yamnaya (Anthony 2017)

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