Widespread horse-based mobility arose around 2,200 BCE in Eurasia

Abstract

Horses revolutionized human history with fast mobility. However, the timeline between their domestication and widespread integration as a means of transportation remains contentious. Here we assemble a large collection of 475 ancient horse genomes to assess the period when these animals were first reshaped by human agency in Eurasia. We find that reproductive control of the modern domestic lineage emerged ~2,200 BCE (Before Common Era), through close kin mating and shortened generation times. Reproductive control emerged following a severe domestication bottleneck starting no earlier than ~2,700 BCE, and coincided with a sudden expansion across Eurasia that ultimately resulted in the replacement of nearly every local horse lineage. This expansion marked the rise of widespread horse-based mobility in human history, which refutes the commonly-held narrative of large horse herds accompanying the massive migration of steppe peoples across Europe ~3,000 BCE and earlier. Finally, we detect significantly shortened generation times at Botai ~3,500 BCE, a settlement from Central Asia associated with corrals and a subsistence economy centered on horses. This supports local horse husbandry before the rise of modern domestic bloodlines.