Bekoff, M. and Allen, C. (1995) Teleology, function, design, and the evolution of animal behaviour. Trends in Ecology and Evolution 10(6):253--263

Concerns about teleological language in evolutionary biology focus on the notions of function, design and adaptation. Accounts that naturalise these ideas are currently popular. In keeping with recent developments in evolutionary theory and philosophy of biology, three naturalistic analyses of function -- current utility, historical function, and functions as capacities -- should be differentiated. All have roles to play in biology, although the historical conception seems most central to evolutionary theory. While rarely distinguished from function, design should be regarded as an extension of the notion of historical function. We consider the utility of this distinction for the study of behaviour.