Western Steppe Herders
In archaeogenetics, the term Western Steppe Herders (WSH), or Western Steppe Pastoralists, is the name given to a distinct ancestral component first identified in individuals from the Eneolithic steppe around the turn of the 5th millennium BC, subsequently detected in several genetically similar or directly related ancient populations including the Khvalynsk, Sredny Stog, and Yamnaya cultures, and found in substantial levels in contemporary European, West Asian and South Asian populations. This ancestry is often referred to as Yamnaya ancestry, Yamnaya-related ancestry, Steppe ancestry or Steppe-related ancestry. Western Steppe Herders are considered descended from a merger between Eastern Hunter-Gatherers (EHGs) and Caucasus Hunter-Gatherers (CHGs). The WSH component is modeled as an admixture of EHG and CHG ancestral components in roughly equal proportions, with the majority of the Y-DNA haplogroup contribution from EHG males. The Y-DNA haplogroups of Western Steppe Herder males are not uniform, with the Yamnaya culture individuals mainly belonging to R1b-Z2103 with a minority of I2a2, the earlier Khvalynsk culture also with mainly R1b but also some R1a, Q1a, J, and I2a2, and the later, high WSH ancestry Corded Ware culture individuals mainly belonging to haplogroup R1b in the earliest samples, with R1a-M417 becoming predominant over time. Around 3,000 BC, people of the Yamnaya culture or a closely related group, who had high levels of WSH ancestry with some additional Neolithic farmer admixture, embarked on a massive expansion throughout Eurasia, which is considered to be associated with the dispersal of at least some of the Indo-European languages by most contemporary linguists, archaeologists, and geneticists. WSH ancestry from this period is often referred to as Steppe Early and Middle Bronze Age (Steppe EMBA) ancestry. This migration is linked to the origin of both the Corded Ware culture, whose members were of about 75% WSH ancestry, and the Bell Beaker ("Eastern group"), who were around 50% WSH ancestry, though the exact relationships between these groups remains uncertain.