Abstract
The adaptationist program attempts to determine what selective advantages have contributed to the shaping of the phenotype. Evolutionary change falls far short of being a perfect optimization process. Stochastic processes and other constraints on selection prevent the achievement of perfect adaptedness. Evolutionists must pay more attention to these constraints than they have in the past. As already stressed by Darwin, (1859) there is no selective premium on perfect adaptation. Even though the adaptationist program has been occasionally misapplied, particularly in an uncontrolled reductionist manner, its heuristic power justifies its continued adoption under appropriate safeguards. The application of the adaptationist program has led to important discoveries in many branches of biology.