Australia’s Aboriginal Martu people hunt kangaroos and set small grass fires to catch lizards, as they have for at least 2,000 years. A University of Utah researcher found such man-made disruption boosts kangaroo populations – showing how co-evolution helped marsupials and made Aborigines into unintentional conservationists. “We have uncovered a framework that allows us to predict when human subsistence practices might be detrimental to the environment and when they might be beneficial,” says Brian Codding, an assistant professor of anthropology.