What was the first lifeform like? What was the first fish or mammal? Is it even possible to know? In this episode, we look to the fossil record to help us trace our roots back to the Last Universal Common Ancestor. Paleontologist Neil Shubin joins us to talk about discovering a remarkably cool fossil that helped us understand how life evolved over billions of years. We also take a field trip to the Hall of Ancestors and examine a few branches on the tree of life. And we learn why figuring out how life began on earth could help us as we find life elsewhere in the universe.

This episode is sponsored by Pillsbury Crescent Rolls, KiwiCo (kiwico.com/brains) and Quip (getquip.com/brainson). You can support the show at brainson.org/donate