Chen (2006) has located the origin of the statement of maximum power as a formal principle in a tentative proposal by Alfred J. Lotka (1922a, b). Lotka's statement sought to explain the Darwinian notion of evolution with reference to a physical principle. Lotka's work was subsequently developed by the systems ecologist Howard T. Odum in collaboration with the chemical engineer Richard C. Pinkerton, and later advanced by the engineer Myron Tribus.