Climate, habitats, and food resources—Environmental influences on early human occupation in the Nihewan Basin, East Asia

Over the past century, the Nihewan Basin is a key area for studying Quaternary environmental changes and hominin adaptations in East Asia and has served as a vital region for exploring the evolution of early human cultures. However, the insufficient research on human-environment interactions in this region has hindered a comprehensive understanding of hominin evolutionary processes. Here, we quantify climatic variations, reconstruct ecosystem landscapes, analyze the richness of food taxa potentially exploitable by hominins, and evaluate environmental impacts on human activities in the Nihewan Basin for the last 3.3 Ma. Results show that (1) temperature and precipitation have displayed an overall declining trend since 3.3 Ma, suggesting that hominins lived in warmer and wetter conditions than today; (2) during this time span, the Nihewan paleolake formed, expanded, and eventually contracted into a riverine system. Vegetation shifted from closed forests to forest-grassland and grassland/desert. In these landscapes, mammals coexisted with hominins in expanding lakeside grassland habitats; (3) a decline in the overall richness of food taxa was partially offset by rising relative proportions of easily exploitable taxa and the persistent representation of staples; and (4) the initial settlement of hominins in the Nihewan Basin may have been associated with its relatively open landscapes and a high richness of food taxa, while their prolonged occupation may have been supported by further landscape opening, an increased relative proportion of high-utility plant taxa, and the persistent representation of staple food taxa. Technological advancements may have played an important role in early human adaptation to environmental challenges. These findings significantly contribute to our understanding of hominin behavioral adaptation to environmental changes.