Spencer Wells is an Explorer-in-Residence at the National Geographic Society and the director of the Genographic Project. After studying under genetic pioneer Luigi Cavalli-Sforza at Stanford University, he began an unusual career that mixes science, writing, and filmmaking. His acclaimed first book, "The Journey of Man," combined his own DNA research with the work of archaeologists, paleoanthropologists, paleoclimatologists, and linguists to show how modern humans came to populate the planet.