Project description:Through the use of proteomic analysis of 32 dental calculus samples from anceint Mongolia, we show that ruminant dairying was present in Mongolia by at least 3000 B.C.E., over 1500 years prior to previously published work. Excitingly, the earliest site with dairy evidence has been identified as archaeologically Afanasievo, supporting the hypothesis that dairy practices and animals likely entered the Eastern steppe with migrating western steppe populations. Furthermore, at 1200 B.C.E. we detect the first direct evidence for horse milk consumption, demonstrating the Bronze Age origins of equine dairying on the eastern steppe which occurred concomitantly with early evidence for horse bridling and riding in the region. The incorporation of horse milk and riding into early Mongolian subsistence strategies led to dramatic economic and demographic shifts that enabled the formation of the well-known steppe empires.
Project description:BackgroundThe redundancy hypothesis predicts that the species redundancy in a plant community enhances community stability. However, numerous studies in recent years questioned the positive correlation between redundancy and stability.MethodologyWe explored the relationship between the species redundancy, functional redundancy and community stability in typical steppe grassland in Northern China by sampling grassland vegetation along a gradient of resource availability caused by micro-topography. We aimed to test whether community redundancy enhanced community stability, and to quantify the relative importance of species redundancy and functional redundancy in maintaining community stability.ResultsOur results showed that the spatial stability of plant community production increases with increased supply of soil resources, and the functional redundancy instead of species diversity or species redundancy is correlated with the community stability. Our results supported the redundancy hypothesis and have implications for sustainable grassland management.