I highly recommend Patient Zero, the latest episode of the podcast RadioLab. It covers Typhoid Mary, the origin of HIV, and the diffusion of ideas. Evocative as always, but what I like the most is how they add new information to stories you think you know. For one, you really feel sorry for Mary. And I've read quite a bit on the origin of HIV (a great way to learn more about phylogenetics!) but RadioLab takes it back even further and highlights some research I hadn't seen. Related: I haven't read it yet, but Tyler Cowen really likes Jacques Pepin's new book, The Origin of AIDS -- more happy reading for Christmas break.