Published online by Cambridge University Press: 28 February 2022
Darwin's theory of evolution by means of natural selection is an extremely powerful explanatory device. For its rigorous application to any phenomenon it requires only that some form of variation in the manifestation of the phenomenon exists, that the variations can persist in time, and that the properties of the variants cause them to have different average persistence times. So, for example, one could make a Darwinian explanation of the frequency of different sorts of rocks. There is variation in the hardness of rocks, they persist in time and indeed are being formed anew, and the harder rocks are more “adapted” to survive the weathering and erosion of wind and water. A similar story can be told about political parties, rumors, jokes, stars and discarded soft drink containers.