The emergence of food production represents one of the most significant positive changes in the history of human society. Food production set the stage for virtually all subsequent cultural developments. Coincident with these changes was the rise of cultural selection replacing natural selection as the determining force in the ecology and evolution of plant and animal species. Food production was tightly tied to climate and drought and significant changes in these factors often resulted in disruption of production and cultural collapse. This award investigates the origins of food production in the tropical lowlands of Belize, Central America occurring from 3000-6000 years ago and the ecological and cultural response to a three-century drought that began 4200 years ago. Climate modeling, environmental reconstruction and archaeological inference of human adaptation will be used to evaluate the long-term relationships among these factors and changing socio-environmental dynamics. This study will provide insights to the experience of thousands of generations of human responses to environmental change and potential guidance so that future generations can be more resilient to major environmental changes. This research is transformative in advancing basic understanding of interactions between how human populations feed themselves and tropical forest ecology in response to profound environmental change. <br/><br/>This award will examine how drying environmental conditions affect human subsistence practices and how intensified food production, in turn, affect local vegetation patterns. Food production is one of the most significant developments in the history of the human species and as the determining force in the evolution of a select number of plant and animal species. Food production has long been acknowledged as setting the stage for virtually all subsequent cultural developments by increasing the carrying capacity of land, the degree of sedentism that is possible as well as greater population density. As a result, the production of food was a required prerequisite for the establishment of urban life. Food production is also necessary to underwrite the division of labor within society that allowed farmers to support ever-increasing numbers of non-producers such as political rulers, priests, engineers and scientists. Environmental change is often posited as resulting in cultural collapse. The reconstruction of human occupation and forest floral species diversity in the tropical lowlands of northern Belize, Central America will be reconstructed from 6000-3000 year ago to document how food production and settlement patterns were affected by climate change and, in turn, how local vegetation was reconstituted. This reconstruction will be accomplished by combining archaeological excavation that document human habitation and lake sediment coring to reconstruct changing patterns of plant pollen from economically useful species and charcoal that result from human burning of local vegetation to increase soil productivity. Research will focus on the "4.2 ka BP event" that caused three centuries of climate disturbance world-wide between 4200 and 3900 years ago. Evidence of human settlement patterns and diet from before, during and after this period will be used to evaluate paleoecological evidence of changing species availability and the extent of anthropogenic disturbance through the use of fire. Evidence of human settlement patterns and diet will be evaluated in light of expectations of niche construction theory (NCT) and optimal foraging theory (OFT) and related to evidence of changing species availability and the extent of anthropogenic disturbance on the landscape with fire.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.