ABSTRACT
This chapter describes quantitative evolutionary theory their application to situations in which social interactions play an important role in determining variation in individual characteristics empirical studies on cooperative breeding that have successfully measured the parameters specified in evolutionary theory. One of the major advances in studies of sociality has been the introduction of Darwinian evolutionary theory. There are thus two main aspects to this theory: heritable variation, concerned with how variations are passed from parent to offspring, and natural selection, concerned with the relationship between the characteristics of an organism and their survival and reproduction in a specific environment. In models of evolution in a social environment this double counting is avoided by assigning fitness directly to the individual who survives and/or reproduces. In order to better understand the evolution of social behavior, researchers need to actually measure the fitness consequences for both the actor and recipient involved in social interactions rather than assuming altruistic selection based on incomplete information.
