Arabian hydroclimate and human population dynamics since the middle Pleistocene

The Arabian Peninsula, a pivotal Africa-Eurasia land bridge, is crucial for understanding the human evolution and global dispersal. Orbital-scale increases in monsoonal precipitation periodically transformed the peninsula into widespread savannahs—termed “Green Arabian” periods (GAPs), which facilitated recurrent human occupation. GAPs fundamentally modulated Pleistocene population connectivity and demography between continents. Despite analysis of extensive archaeological remains from the Arabian Peninsula over the last decade, the regional environmental context of human dispersals remains poorly understood due to the absence of continuous paleoenvironmental records from hominin habitats, especially for the Pleistocene. Fortunately, an alternative to terrestrial sediments is marine dust record emanated from the Arabian Peninsula, since they are continuous and well-dated and have the potential to trace the aridity shifts. Here we present multi-proxy and high-resolution Arabian dust records from the western equatorial Indian Ocean spanning the last 500 kyr, to assess orbital-scale hydrological variations as regulators of human populations in Arabia.