In the century and a half since Charles Darwin wrote his seminal On the Origin of the Species, our understanding of evolution has changed quite a bit. For one, we have not only identified the inheritance molecule DNA, but have determined its sequence in many animals and plants. Evolution has evolved, and we take a look at some of the recent developments. A biologist describes the escalating horn-to-horn and tusk-to-tusk arms race between animals, and a paleoanthropologist explains why the lineage from chimp to human is no longer thought to be a straight line but, instead, a bush. Also, New York Times science writer Carl Zimmer on the diversity of bacteria living on you, and which evolutionary concepts he finds the trickiest to explain to the public. Guests: Douglas Emlen – Biologist, University of Montana and author of Animal Weapons: The Evolution of Battle Bernard Wood – Paleoanthropologist, George Washington University Carl Zimmer – Columnist for the New York Times Learn more about your ad choices. Visit megaphone.fm/adchoices