In this episode, theoretical physicist, cosmologist and astrobiologist Paul Davies ponders the question of whether life originated more than once on earth, and how to find examples of a second origin if it did. Plus we'll test your knowledge of some recent science in the news. Websites mentioned on this podcast include: www.sciam.com/sciammag or tinyurl.com/3b8voo; www.beyond.asu.edu; www.sciam.com/sciambody; www.mayoclinic.com