Patreon: https://www.patreon.com/seanmcarroll Blog post with audio player, show notes, and transcript: https://www.preposterousuniverse.com/podcast/2025/05/12/314-karen-lloyd-on-the-deep-underground-biosphere/ There are living creatures dwelling deep below the surface of the Earth, as deep as we are able to drill. These hearty microorganisms are related to more familiar life forms on land and under water, but the operate and survive in ways that are quite different from what we're familiar with. They live off of nutrients that have penetrated from the surface, or sometimes off of pure electrons. Karen Lloyd is a scientist who has traveled around the world studying these organisms, as she explains in her new book Intraterrestrials: Discovering the Strangest Life on Earth. Karen Lloyd received a Ph.D. in marine sciences from the University of North Carolina. She is currently the Wrigley Chair in Environmental Studies and Professor of Earth Sciences at the University of Southern California. Among her awards are a Sloan Fellowship, a Simons Early Career Investigator, and a NASA Early Career Fellowship. Mindscape Podcast playlist: https://www.youtube.com/playlist?list=PLrxfgDEc2NxY_fRExpDXr87tzRbPCaA5x Sean Carroll channel: https://www.youtube.com/c/seancarroll #podcast #ideas #science #philosophy #culture