A People in Flux Guest: Robert Hitchcock, Professor, Evolutionary Anthropology, University of New Mexico The San people of Southern Africa are one of the most studied on the planet—you may know them from their famous Click language—but they have many of the same challenges we all face, including how to respond to Covid-19. Viking Board Games Guest: David Petts, Associate Professor, Archaeology, Durham University, and Member, Institute of Medieval and Early Modern Studies A crowd-sourced dig team unearthed a board game piece on the Holy Island of Lindisfarne in the UK, connecting early Christianity with the Vikings. The Strategic Importance of Guano Islands Guest: Daniel Immerwahr, Associate Professor, History, Northwestern University, and author, "How to Hide an Empire: A History of the Greater United States" Guano Islands are just what they sound like—tiny rocks in the ocean covered with bird droppings. And nothing more. But nations fought over them, or at least diplomatically elbowed each other. Because they were worth enormous amounts—for fertilizer. Guano was a powerful natural source of nitrogen. This is the story of how America built its guano island empire.