The Confusions of Fitness

The central point of this essay is to demonstrate the incommensurability of'Darwinian fitness' with the numeric values associated with reproductive rates used in population genetics. While sometimes both are called 'fitness', they are distinct concepts coming from distinct explanatory schemes. Further, we try to outline a possible answer to the following question: from the natural properties of organisms and a knowledge of their environment, can we construct an algorithm for a particular kind of organismic life-history pattern that itself will allow us to predict whether a type in the population will increase or decrease relative to other types?