George Johnson’s textbook has often been considered a student favorite. Dr. Johnson has written this non-majors textbook from the ground up to be an engaging and accessible learning tool with an emphasis on "how things work and why things happen the way they do". This authoritative textbook features a straightforward, clear writing style and a wide variety of media assets to enhance the content of the textbook. The strength of the fourth edition is the integration of many tools that are designed to inspire both students and instructors. The multi-media package for the new edition stretches students beyond the confines of the traditional textbook to include high interest video clips and animations of key biological concepts. 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.