I welcome renowned evolutionary paleobiologist Bruce S. Lieberman, a professor at the University of Kansas in Lawrence, who is an expert on how cosmic cataclysms have impacted the evolution of life here on Earth.  Massive nearby supernovae, gamma-ray bursts (GRBs) as well as asteroidal and cometary impactors have each played a role in our planet’s long tape of life.  And if we were able to rewind that tape and roll the die once more?  Would intelligent life have manifested itself here at all?  This lively episode delves into our long road from Trilobite to Human Intelligence.