Figure 2.

A schematic of the relationship between the biological process of evolution and theory. The example given illustrates classical population-genetic theory. A formal system is created to represent elements of evolution (e.g. p(t) represents the number of the blue genotype at time t). A set of premises is specified (e.g. initial genotype numbers, how genotypic fitnesses are determined, etc.—this is embodied by the mapping F). Rules of deduction are then followed (e.g. repeated application of the mapping F) to obtain new statements about elements of the formal theory (e.g. p(1); p(2); p(3), etc.). These new elements are then interpreted in terms of evolution (e.g. as predictions about genotype numbers at future times).