The first horse herders and the impact of early Bronze Age steppe expansions into Asia

Abstract

The Yamnaya expansions from the western steppe into Europe and Asia during the Early Bronze Age (~3000 BCE) are believed to have brought with them Indo-European languages and possibly horse husbandry. We analyze 74 ancient whole-genome sequences from across Inner Asia and Anatolia and show that the Botai people associated with the earliest horse husbandry derived from a hunter-gatherer population deeply diverged from the Yamnaya. Our results also suggest distinct migrations bringing West Eurasian ancestry into South Asia before and after but not at the time of Yamnaya culture. We find no evidence of steppe ancestry in Bronze Age Anatolia from when Indo-European languages are attested there. Thus, in contrast to Europe, Early Bronze Age Yamnaya-related migrations had limited direct genetic impact in Asia. Europe PMC Funders Author Manuscripts The vast grasslands making up the Eurasian steppe zones, from Ukraine through Kazakhstan to Mongolia, have served as a crossroad for human population movements during the last 5000 years (1–3), but the dynamics of its human occupation—especially of the earliest period—remain poorly understood. The domestication of the horse at the transition from the Copper Age to the Bronze Age ~3000 BCE, enhanced human mobility (4, 5) and may have triggered waves of migration. According to the “Steppe Hypothesis,” this expansion of groups in the western steppe related to the Yamnaya and Afanasievo cultures was associated with the spread of Indo-European (IE) languages into Europe and Asia (1, 2, 4, 6). The peoples who formed the Yamnaya and Afanasievo cultures belonged to the same genetically homogenous population, with direct ancestry attributed to both Copper Age (CA) western steppe pastoralists, descending primarily from the European Eastern hunter-gatherers (EHG) of the Mesolithic, and to Caucasian groups (1, 2), related to Caucasus hunter-gatherers (CHG) (7). * Correspondence to: rd109@cam.ac.uk (R.D.); ewillerslev@snm.ku.dk (E.W.). Author contributions: EW, KK, AO, and AW: initiated the study. EW, RD, KK, AO, and PBD: designed the study. EW and RD: led the study. KK and AO: led the archaeological part of the study. GK, MP, and GB: led the linguistic part of the study. PBD, CZ, FEY, IU, CdF, MI, HS, ASO, and MEA: produced data. PBD, RM, JK, JVMM, SR, KHI, MS, RN, AB, JN, EW, and RD: analyzed or assisted in analysis of data. PBD, RM, JK, JVMM, RD, EW, AO, KK, GK, MP, GB, BH, MS, and RN: interpreted the results. …