Time keeps on ticking, ticking … and as it does, evolution operates to produce remarkable changes in species. Wings may appear, tails disappear. Sea creatures drag themselves onto the shore and become landlubbers. But it’s not easy to grasp the expansive time scales involved in these transformative feats. Travel through millennia, back through mega and giga years, for a sense of what can occur over deep time, from the Cambrian Explosion to the age of the dinosaurs to the rise of Homo sapiens. Guests: Lorna O’Brien – Evolutionary biologist, University of Toronto Ivan Schwab – Professor of ophthalmology, University of California, Davis. His blog Don Henderson – Curator of dinosaurs, Royal Tyrrell Museum, Drumheller, Canada Gregory Cochran – Physicist, anthropologist, University of Utah Todd Schlenke – Biologist, Emory University Descripción en español First released April 2, 2012 Learn more about your ad choices. Visit megaphone.fm/adchoices