Lee Berger is a paleoanthropologist and National Geographic explorer-in-residence. He is best known for his discovery of early human ancestors, including Australopithecus sediba in 2008 and Homo naledi in 2013. He is an award-wining author, speaker and research professor at the Evolutionary Studies Institute at South Africa's University of the Witwatersrand in Johannesburg. On this edition of Conversations, I talk with him about his book Almost Human: The Astonishing Tale of Homo naledi and the Discovery That Changed Our Human History. He co-authored the book with John Hawkes, a paleoanthropologist who works with him on the Rising Star Expedition.