In numerous studies, experimental economists have documented the fact that people tend to propose that divisible goods be divided equally. It has often been proposed, most notably by the sociobiologists, that this tendency may have a biological basis, and might be the product of evolution and natural selection. ;My dissertation addresses methodological and philosophical problems that arise in the course of establishing this naturalistic claim. Specifically, the focus of this dissertation is on the project of using evolutionary game theory to (...) model the emergence of behavioral norms in a population. ;Chapter 1 briefly surveys the experimental economics literature that supports the existence of such behavioral propensities, and gives an overview of the dissertation. Chapter 2 introduces the fundamental concepts of game theory and evolutionary game theory. Chapter 3 argues that certain robustness failures may be overcome if group selection mechanisms are incorporated into the evolutionary models. Chapter 5 defends Peter Railton's causal theory of explanation, and argues that it best accommodates the dynamical models of evolutionary game theory. Chapter 6 addresses the question of whether a descriptive account of the origins of our moral intuitions is relevant to the normative project of identifying our moral obligations, and critiques arguments by Peter Singer and Peter Unger that our moral intuitions lack justification. (shrink)