Abstract: Malaria is a disease that had its origins in the coevolution of humans’ changing their physical environment, certain parasites that thrived in the human bloodstream, and an insect vector (the Anopheles mosquito species) that spread those parasites. Over tens of thousands of years, as early humans expanded into tropical Africa and across tropical Eurasia, malaria parasites continued to take advantage of human migration and the need to gather into stable social communities. Eventually the parasites moved with their human hosts into the nascent river-basin communities that would develop into sedentary agricultural settlements. Malaria has thus been a disease created and sustained by human transformations of the landscape and the ecology of agriculture. This paper is a part of the five-year Rockefeller Foundation-sponsored project of the Boston University African Studies Center and the Harvard School of Public Health entitled The Effect of Maize Cultivation on the Transmission of Malaria in Ethiopia. The project has undertaken a study that associates the distribution and intensity of malaria transmission with the expansion of maize as a dominant crop in the ecology of African agriculture.