"In the aDNA literature, “steppe ancestry” is a phrase used since Allentoft et al.147 and Haak et al.148 to refer to the typical Yamnaya pattern of genetic ancestry. The principal components of steppe ancestry were EHG & CHG, each in robust proportions, like Khvalynsk, although often with more CHG than in the Khvalynsk/Progress-2 population, with an added component of Anatolian Farmer (AF) ancestry (5–15 %) that was absent from the Khvalynsk/ Progress-2 populations149. Also, the Khvalynsk/Progress-2 mating network has not yet yielded the Y-haplogroup mutations that were directly ancestral to the typical Yamnaya form of R1b (R-Z2103). The R-V1636 form of R1b, found in males at Khvalynsk, Ekaterinovka Mys, Berezhnovka II, and Progress-2, identifies a branch that split from the Yamnaya branch defined by R-P297 > R-M269 > R-L23 > R-Z2103 (yfull.com). This entire branch is absent from the sampled Eneolithic males from the steppes, appearing for the first time in Yamnaya males. The evolution of Yamnaya Y-haplogroup ancestry occurred in a still-unsampled Eneolithic population. The Eneolithic populations around the Dnieper Rapids150 were even more different from Yamnaya. All those sampled were admixtures of EHG (primarily) and Western European Hunter-Gatherers (WHG) similar to the Iron Gates Mesolithic populations151. Among 30 published individuals from three Neolithic and Eneolithic cemeteries (Dereivka-1, Vil’nyaka, and Vovnigi) in the Dnieper River valley dated 5200–4400 BC, assigned to the Dnieper-Donets culture, there were a few individuals with minor (<10 %) CHG ancestry, but most had none152. The Khvalynsk/Progress-2 populations had substantial CHG ancestry but no WHG ancestry, ubiquitous in Dnieper-valley populations. This indicates that the Dnieper-Donets mating network did not extend eastward to the Volga, nor westward to the Criş and early Tripol’ye farmers, whose ancestry was typical of European farmers (AF or EEF)153. The Dnieper-Donets people seem to have been an endogamous population focused on the rich resources of the Dnieper Rapids. Their substantial WHG ancestry, nearly absent in Yamnaya individuals, rules them out from being a major source for the Yamnaya. The Sredni Stog culture succeeded and replaced the Dnieper-Donets culture in the strategic Dnieper Rapids and throughout the steppes of Ukraine beginning around 4500–4300 BCE and ending in the late fourth millennium BCE with the appearance of Yamnaya. Unpublished Sredni Stog male genomes exhibit admixture ‘cocktails’ with the same basic elements as Yamnaya (EHG & CHG & AF). The CHG & EHG component was like Khvalynsk/ Progress-2, suggesting an eastern origin for at least part of the Sredni Stog population, and the AF component could have come from either the early Maikop or Tripol’ye populations. Sredni Stog introduced into the Ukrainian steppes new funeral customs (the Khvalynsk or ‘Yamnaya’ position), ceramic types (shell-tempered like Khvalynsk), and economies (large numbers of horse bones) that had appeared earlier on the Volga. Sredni Stog has for decades been recognized154 as an Eneolithic ancestor of Yamnaya influenced by late Khvalynsk, early Maikop, and the Tripol’ye and Varna cultures. But neither R1b Z-2108 nor its immediate ancestral forms are found among sampled Sredni Stog males, most of whom belonged to the R1a or I haplogroups, unlike Volga males. The sampled Sredni Stog populations included individuals who autosomally resembled Yamnaya a millennium before the Yamnaya culture appeared. But within that population the Yamnaya Y-haplogroup patriline evolved in a region that has not been sampled"