Evolutionary biologists standardly treat organisms as agents: they have goals and purposes and preferences, and their behaviors and adaptive traits contribute to the achievement of their goals. This explanatory practice brings evolutionary biology into conceptual contact with rational choice theory, which provides models of how people make decisions and act on them. In Agents and Goals in Evolution
(Oxford University Press, 2018), Samir Okasha
explores the fascinating and complex links between evolutionary biology and rational choice theory, arguing that “agential thinking” in adaptationist explanations of nonhuman organisms is justified by providing explanatory purchase that goes beyond using the concept of function. He also argues how natural selection does not necessarily or even probably lead to the most adapted (or fittest) traits, and considers how and when the idea of utility maximization in economics has its valid analogue in the idea of adaptive fitness.