Evolutionary Individuals

Abstract

Abstract This chapter defends an evolutionary understanding of biological individuals. I use the example of Galapagos finches to explain the role played by the concept of the individual in evolutionary theory, and argue that what’s needed is to find the definition that best supports this role. My ‘levels of selection’ account defines evolutionary individuals in terms of policing and Demarcating Mechanisms that determine which compositional units are capable of evolving by natural selection. I offer an ‘operational strategy’ that explains how to apply the definition in practice. A core (and novel) claim is that evolutionary biologists are making good use of a highly idealised concept here, just as physicists make good use of the ‘ideal gas’ concept. I’ll explain what the concept ignores, and how the abstraction is best navigated for maximal theoretical success. Finally, the chapter explores some dimensions of the concept that are underdetermined by facts, such as whether to adopt a historical or a forwards-looking version.