Dr. Knoll describes the causes of the previous five extinctions on Earth and the possibility of a sixth. He explains how the specific causes of different mass extinctions tend to impact ecosystems in distinct and unexpected ways. He discusses the threat of a sixth mass extinction. A key issue is how well evolutionary mechanisms can adapt to this type of destruction.
Yvonne Stapp runs Science for the Public, a grassroots organization whose mission is to improve public understanding of science. Science is essential to the vitality of modern culture, and science depends on public commitment to the scientific community
Andrew Knoll, Ph.D., is the Fisher Professor of Natural History and Professor of Earth and Planetary Sciences at Harvard University. He is a member of the National Academy of Sciences, the American Academy of Arts and Sciences, the American Philosophical Society, and the American Academy of Microbiology. Dr. Knoll has received many prestigious awards for his outstanding research on the interdependence of the evolution of life and the evolution of our planet. He is also the author of \_Life on a Young Planet: The First Three Billion Years of Life on Earth\_ (2003).