Paul Ehrlich has been a pioneer in alerting the public to the problems of overpopulation, and in raising issues of population, resources and the environment as matters of public policy. He was perhaps the first person to broach the topic in a broad context with his book The Population Bomb in 1968. His book — cowritten with wife Anne — has had a profound and lasting impact on the discourse on population growth. In his current work at the Center for Conservation Biology at Stanford, Ehrlich, an entomologist, studies dynamics and genetics of butterflies. Another special interest of Ehrlich’s is cultural evolution, especially with respect to environmental ethics, and he is deeply involved in the Millennium Assessment of Human Behavior (MAHB).