 In the broadest terms, theories of evolution seek to explain why species are the ways they are. For many evolutionists, this means explaining the possession by species of characteristic adaptations. It also means explaining diversity within species. The general mark of modern theories of cultural evolution is their insistence on the significance of cultural inheritance—particularly various forms of learning from others—for both of these questions. The prima-facie case for cultural evolutionary theories is irresistible. Members of our own species are able to survive and reproduce in part because of habits, know-how and technology that are not only maintained by learning from others, they are initially generated as part of a cumulative project that builds on discoveries made by others. And our own species also contains sub-groups with different habits, know-how and technologies, which are once again generated and maintained through social learning. Social learning is also an important agent of adaptation, and perhaps of speciation, in animals. The question is not so much whether cultural evolution is important, but how theories of cultural evolution should be fashioned, and how they should be related to more traditional understandings of organic evolution.