Selection

Abstract

One of Darwin’s major contributions to our understanding of evolution, namely natural selection, seems a very simple idea. However natural selection is a very subtle concept and biologists and philosophers have been struggling for decades to make sense of it and justify its explanatory power. In this chapter, fi rst I present the most general formulations of natural selection in terms of necessary conditions, and I argue that none of them capture all the aspects of the concept. Second, I question the explanatory status of selection, asking what exactly it is supposed to explain, and considering its relationship with stochastic factors (i.e. genetic drift). Second, I investigate its metaphysical status, asking whether it can be seen as a law, and to what extent it would deprive evolution of any contingency. The last section presents controversies about the units and levels of selection, and, after exposing the philosophical assumptions proper to various positions, sketches a pluralist conception.