A simplistic view of human evolution is that we are the result of a naturally evolving species. But that idea discounts the many random occurrences that have affected our development. This hour, we’ll talk about how we got to now with Ian Tattersall, curator emeritus in the American Museum of Natural History’s Division of Anthropology and author of The Strange Case of the Rickety Cossack: and Other Cautionary Tales from Human Evolution (Palgrave Macmillan).