How Individualized Niches Arise: Defining Mechanisms of Niche Construction, Niche Choice, and Niche Conformance

The debate between the extended evolutionary synthesis (EES) and the modern synthesis (MS) partly relies on different interpretations of niche construction. We dissect the umbrella term of niche construction into three separate mechanisms: niche construction (taken in a narrow sense), in which individuals make changes to the environment; niche choice, in which individuals select an environment; and niche conformance, in which individuals change their phenotypes. Each of these individual-level mechanisms affects an individual’s phenotype-environment match, its fitness, and its individualized niche, defined in terms of the environmental conditions under which an individual can survive and reproduce. Our conceptual framework distinguishes several ways in which individuals alter the selective regimes that they and other organisms experience. It also places clear emphasis on individual differences and construes niche construction and other processes as evolved mechanisms. We therefore argue that our framework helps to resolve the tensions between EES and MS.