How Ecosystem Evolution Strengthens the Case for Functional Pluralism

Functional Biodiversity and the Concept of Ecological Function

This chapter argues that the common claim that the ascription of ecological functions to organisms in functional ecology raises issues about levels of natural selection is ill-founded. This claim, I maintain, mistakenly assumes that the function concept as understood in functional ecology aligns with the selected effect theory of function advocated by many philosophers of biology (sometimes called “The Standard Line” on functions). After exploring the implications of Wilson and Sober’s defence of multilevel selection for the prospects of defending a selected effect account of ecological functions, I identify three main ways in which functional ecology’s understanding of the function concept diverges from the selected effect theory. Specifically, I argue (1) that functional ecology conceives ecological functions as context-based rather than history-based properties of organisms; (2) that it attributes to the ecological function concept the aim of explaining ecosystem processes rather than that of explaining the presence of organisms within ecosystems; and (3) that it conceives the ecological functions of organisms as use and service functions rather than design functions. I then discuss the extent to which the recently proposed causal role and organizational accounts of ecological functions better accord with the purposes for which the function concept is used in functional ecology.