George B. Johnson, Ph.D., is a professor of biology at Washington University in St. Louis and a professor of genetics at the university's School of Medicine. He is a prolific author of life science texts and curriculum products in a variety of media. New to his list of works are the Explorations of Human Biology CD-ROM and the textbook Human Biology, both offered by Wm. C. Brown Publishers. Johnson is acknowledged as an authority on population genetics and evolution variability, and he has published more than 50 research papers dealing with these and related topics. Visitors to the St. Louis Zoo can appreciate Johnson's work in the Living World, the educational center of which he is the founding director.Raven, Peter H. is the author of 'Biology', published 2007 under ISBN 9780073227399 and ISBN 0073227390.