Richard Levins (June 1, 1930 – January 19, 2016)[3] was a Marxist biologist, population geneticist, biomathematician, mathematical ecologist, and philosopher of science[4][5] who researched diversity in human populations. Until his death, he was a university professor at the Harvard T.H. Chan School of Public Health and a long-time political activist. He was best known for his work on evolution and complexity in changing environments and on metapopulations.