The Importance of a “Quantitative Genetic” Approach to the Evolution of Artifact Morphological Traits

Recent years have seen substantial growth in the application of evolutionary approaches to spatial and temporal variation exhibited in archaeological data. As is now well known, the application of this approach rests on the basis that artifacts are an expression of a genuine evolutionary system mediated by transmission (via social learning), variation in transmitted elements, and differential replication of transmitted elements across time. While this provides the necessary fundamental basis for the application of an evolutionary approach to artifactual variation, application of the term “evolution” still provides a source of confusion for some archaeologists. Part of this confusion may stem from an underdeveloped body of theory that conceptually makes explicit the link between the evolution of socially transmitted information and the expression of that evolutionary process in terms of physical artifacts. This is especially the case given that artifactual variation is inevitably influenced by several different factors (e.g., raw material properties and/or post manufacture attrition), not all of which are necessarily heritable in systems of social learning. In order to resolve these difficulties and make more clear the case for an evolutionary approach to artifactual variation, there is a need for an explicit quantitative body of theory that links statistical variation in artifactual traits to factors such as selection and drift when (1) sources of artifact variation are multiple and not all necessarily heritable, (2) the proximate socially transmitted elements are unknown, and (3) many artifactual traits will be influenced simultaneously by multiple aspects of socially transmitted practices. Here, it is argued that a “quantitative genetic” approach can resolve these problems.