In Chapter 3, we traced the dispersal of hominins from Africa to Asia and Europe and saw the emergence of new species: Homo erectus, H. antecessor, and H. heidelbergensis. After 400,000 years ago, two new species arose: the Neanderthals (Homo neanderthalensis) in western Eurasia and Homo sapiens, or modern humans, in Africa. Recent genetic research has also uncovered a new hominin, the Denisovan, which shared a common ancestor with both H. sapiens and H. neanderthalensis. Eventually, H. sapiens spread out from Africa and replaced earlier species elsewhere. In this chapter we focus on these three humans, their behavior, and their expansion.