Niles Eldredge is a curator at the American Museum of Natural History and was curator of its popular Darwin exhibit. He has blogged as if he were channeling Charles Darwin.

Heather Strang is director of the Centre for Restorative Justice at Australian National University. She has done research in Australia and Great Britain on the effectiveness of restorative justice.

Christopher D. Marshall wrote Beyond Retribution: A New Testament Vision for Justice, Crime and Punishment. An expert in biblical ethics and peace theology, he teaches religious studies at Victoria University of Wellington in New Zealand.

Pamela Jordan is an associate professor of family and child nursing at the University of Washington and developer of the Becoming Parents Program. Her research focuses on the transition to parenthood and supporting individuals and couples as they become parents.

Judith K. Balswick is senior professor of marital and family therapy in the School of Psychology at Fuller Theological Seminary in Pasadena, Calif.

Jack O. Balswick is senior professor of sociology and family development in the School of Psychology at Fuller Theological Seminary in Pasadena, Calif.

Scott Stanley is co-director of the Center for Marital and Family Studies at the University of Denver. He has published widely both research reports as well as writings for couples, with a key focus on commitment theory and research.

Galena K. Rhoades is a senior researcher for the Center for Marital and Family Studies in the psychology department at the University of Denver.

Glenn W. Olsen is professor emeritus of history at the University of Utah in Salt Lake City. He is the editor of Christian Marriage: A Historical Study.