Trained as an historian of science, he earned his Ph.D. in 2000 from the University of Minnesota. His research has focused on the history of biology in nineteenth and twentieth century United States, and his first book, Breeding Contempt, examined the role of biologists, physicians, and social scientists in the American coerced sterilization movement. Currently, he is working on the topic of vaccines, compulsory vaccination laws, and the public's anxiety over vaccine safety. He is the book review editor for the Journal of the History of Biology, editor of the Rutgers University Press series Studies in Modern Science, Technology and the Environment, and permanent secretary of the Columbia History of Science Group.