Are There (Microbial) Aliens On Earth?

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 Learn more about your ad choices. Visit megaphone.fm/adchoices