DRI’s Erick Robinson, Associate Research Professor of Climate and Archaeology, co-authored a new study that provides insight into North America’s Indigenous communities prior to European contact. The research found that although Indigenous populations varied regionally, the continent saw a population peak around 1150 A.D. before experiencing declines, likely stemming from drought, disease, emigration and warfare. A brief recovery around 1500 A.D. was followed by a sharp decrease upon the arrival of Europeans.