This subcategory gathers theories belonging to biology broadly: the models describing how living things originate, are organized, evolve, and interact with each other and their environment, including the origin and cellular basis of life, the mechanisms and history of evolution by natural and sexual selection, ecological relationships between organisms, and the historical medical and biological theories, sound and superseded alike, that the life sciences have proposed to explain disease and vital processes. A theory placed here concerns life's organization, history or ecology at a level broader than the specific molecular-genetic mechanisms gathered in genetics.