Richard Levins

Richard Levins (1930 to 2016) was an American biologist who worked as a population geneticist, mathematical ecologist and philosopher of science, and who spent about forty years at the Harvard T.H. Chan School of Public Health, where he held the John Rock chair of population sciences. Born in Brooklyn, he studied agriculture and mathematics at Cornell, farmed for a time in Puerto Rico, took his doctorate at Columbia, and taught at the University of Puerto Rico and the University of Chicago before moving to Harvard. He is best known for modelling evolution in changing environments, showing that selection need not maximise adaptation, and for coining the term metapopulation in 1969 for a population of populations; the single equation now called the Levins model describes how patch occupancy balances extinction and colonisation. He also developed loop analysis for causal feedback in ecological systems, wrote The Dialectical Biologist with Richard Lewontin, helped found the Harvard Working Group on New and Resurgent Diseases, and promoted agroecology and gentle pest management in poorer countries. He was a committed Marxist and political activist.