The last decades of the 20th century witnessed strongly growing interest in evolutionary approaches to the human past. Even now, however, there is little real agreement on what evolutionary archaeology is all about. A major obstacle is the lack of consensus on how to define the basic principles of Darwinian thought in ways that are genuinely relevant to the archaeological sciences. Each chapter in this new collection of specially invited essays focuses on a single major concept and its associated key words, summarizes its historic and current uses, and then reviews case studies illustrating that concept's present and probable future role in research. What these authors say shows the richness and current diversity of thought among those today who insist that Darwinism has a key role to play in archaeology. Each chapter includes definitions of related key words. Because the same key words may have the same or different meanings in different conceptual contexts, many of these key words are addressed in more than one chapter. In addition to exploring key concepts, collectively the book's chapters show the broad range of ideas and opinions in this intellectual arena today. This volume reflects-and clarifies-debate today on the role of Darwinism in modern archaeology, and by doing so, may help shape the directions that future work in archaeology will take.