Eating meat is what made us human. At least, that's one of the leading theories to explain how our brains got so big. The theory says that our human ancestors evolved bigger brains as a result of switching from a plant-based to a nutrient-rich meat diet. But earlier this year a Smithsonian researcher discovered that this theory may not have as much meat on its bones as previously believed.

Guests:

Briana Pobiner, paleoanthropologist; research scientist and museum educator with the Human Origins Program at the Smithsonian's National Museum of Natural History

Becky Malinsky, curator of primates, Smithsonian's National Zoo and Conservation Biology Institute

Andrew Barr, paleoanthropologist; assistant professor of anthropology, The George Washington University