Straight from the Horse's Mouth: Timing and Zoogeography of Domesticated Horse Arrivals in Mongolia and China

The timing, geographical pathways, and earliest uses for horses (Equus caballus) in East Asia have long been a scientific puzzle vigorously debated by scholars with different backgrounds across diverse disciplinary fields. Over the past two decades, a wide range of high-resolution evidence has been presented documenting the multi-regional dispersion of domesticated horses, but questions still abound, especially in the eastern regions of Eurasia. This study provides a rigorous critique of this body of evidence and advances hypotheses as to when and where domesticated horses first arrived in Mongolia and China. We present the earliest ancient DNA evidence for the DOM2 genetic lineage of modern domesticated horses in Mongolia and evaluate a comprehensive dataset of radiocarbon dates for East Asian domesticated horses using a Bayesian statistical approach that is powerful but seldom utilized by archaeologists. Our genetic and chronological evidence demonstrates that horses far to the east in Mongolia, interred in monumental prone burial contexts, were domesticated and contemporaneous with the earliest horses documented in western regions of Mongolia and Xinjiang. These results both complicate and clarify major questions related to the occurrence of domesticated horses within the greater region and help to explain the development of horse culture(s) and knowledge on the eastern steppe and at the Late Shang capital of Yinxu.