Evolutionary biologist Dr. Bret Weinstein returns to explore the latest developments in gene splicing, stem cells, lifespan extension, the search for extraterrestrial civilizations, and the next (and perhaps final) step in human evolution - the Fourth Frontier.

Dr. Bret Weinstein is host of the DarkHorse Podcast and a Visiting Fellow in the James Madison Program at Princeton University. Follow him on Twitter at @BretWeinstein.