A study by researchers from the Max Panck Institute of Geoanthropology in Germany suggests that the risk of malaria influenced where prehistoric people lived in sub-Saharan Africa. The research is the first to link early human habitation with the deadly disease and contrasts with early assumptions that prehistoric people moved to different regions due to environmental concerns. The study used existing climate models and environmental data to compare them with maps of early human settlements. It found that prehistoric humans avoided areas where malaria was prevalent long before farming was introduced. The researchers also found that this behavior helped determine human population structures by at least 13,000 years ago. This discovery suggests that malaria was already a problem before agriculture, but likely worsened after people became sedentary and settled at high density due to food production.