Endemic - The baseline level of disease usually present in a community.⏎
Epidemic - An often sudden increase in the level of disease in a specific population over a given period of time.⏎
Disease - Any abnormal condition that affects all or part of an organism, resulting in symptoms such as pain or loss of function.⏎
Evolution - The change in heritable traits in a population of organisms over successive generations.⏎
Ecosystem - A functional unit that consists of all the living organisms in a particular area, as well as the nonliving, physical components in the environment—such as air, soil, water, and sunlight—with which the organisms interact, and how natural and human-made changes affect these interactions.⏎