Rare Earth and Mass Extinction

Please use this link to Peter Ward’s TED talk on mass extinction.  I first heard of Dr. Ward over twenty years ago when he co-wrote Rare Earth, a thought provoking take on the potential for complex life in the universe. 

Paleontologist and astrobiologist Peter Ward studies events such as the Cretaceous-Tertiary extinction event which made dinosaurs go extinct. He is a Professor at University of Washington where he does research on mass extinctions and habitability, conservation biology of coral reefs, as well as paleontology and astrobiology. Ward is the author of Rare Earth and The Medea Hypothesis.