Humans are the dominant species on Earth and ecology is key to understanding the multiple feedbacks through which their activities affect human health. Fundamental principles of ecology, from population to ecosystem levels, will be examined through the lens of human health. Topics include human population growth and carrying capacity, why we age, infectious disease dynamics, the microbiome and human health, sustainable agriculture and food security, sustainable harvest of wild foods, dynamics of pollutants in food webs, ecosystem services to humans, and human impacts of climate change.