ABSTRACT
I n the 1970s, a single sentence uttered on a university campus and containing both the word evolution and the word culture most likely referred to oppos-ing explanations of the same outcome-for instance, a contrast between a view that a behavior is an outcome of genetic evolution (as a sociobiologist might have claimed) and one that behavior is the outcome of a cultural process. During the 1980s, such a sentence may well have spoken of a particular form of evolution: cultural evolution. According to dual inheritance theory, two forms of evolution affecting behavior can be distinguished: genetic evolution, which consists of changes in gene frequencies within a population across time, and cultural evolution, which consists of changes in culturally transmitted information over time (e.g., Boyd & Richerson, 1985; Dawkins, 1976; Durham, 1991; Lumsden & Wilson, 1981; Richerson & Boyd, 2005). Furthermore, both can be modeled within a population genetic framework (Boyd & Richerson, 1985). Though these forms of evolution do not proceed entirely independently of one another (so that, for instance, changes in culture can affect selection and evolution of gene frequencies), the processes are distinct from one another (see, for instance, Laland & Brown, 2002). And one can argue that one or the other is a more potent cause of behavior within a specic domain.
