Keel has written widely about the history of racism and its connections to the modern biological sciences, religious intellectual history, law, medicine, and public health. He is the author of Divine Variations (Stanford University Press 2018). The book offers a new account of the development of scientific ideas about race. Focusing on the production of scientific knowledge over the last three centuries, Keel uncovers the persistent links between pre-modern Christian thought and contemporary scientific perceptions of human difference. He argues that, instead of a rupture between religion and modern biology on the question of human origins, modern scientific theories of race are, in fact, an extension of Christian intellectual history.