Mass Extinctions

**Contemporary Science Issues and Innovations, April 09, 2019 Belmont Media Center

Andrew Knoll, Ph.D., Fisher Professor of Natural History and Professor of Earth and Planetary Sciences, Harvard University.
The Knoll Lab

Dr. Knoll describes the causes of the previous five extinctions on Earth and the possibility of a sixth. He explains that mass extinctions in the past have been caused by different triggers (e.g., glaciation vs ocean anoxia), and that the cause of an extinction tends to impact ecosystems in distinct and unexpected ways. He discusses the threat of a sixth mass extinction, this one complicated by a number of factors. A key issue is how well evolutionary mechanisms can adapt to this type of destruction.

Professor Knoll is a member of the National Academy of Sciences, the winner of numerous awards, most recently one of the most prestigious awards in natural science, the International Prize for Biology, conferred in Tokyo in the presence of the Emperor and Empress of Japan.

Some background:
Myers & Knoll How Will the Sixth Extinction Affect Evolution of Species?
Knoll (interview) Ranking Extinctions by Ecological Impact

Info about Andy Knoll’s book Life on a Young Planet: The First Three Billion Years of Evolution on Earth