Evolutionary epistemology refers to three distinct topics: (1) the biological evolution of cognitive mechanisms in animals and humans, (2) a theory that knowledge itself evolves by natural selection, and (3) the study of the historical discovery of new abstract entities such as abstract number or abstract value that necessarily precede the individual acquisition and usage of such abstractions.
"Evolutionary epistemology" can refer to a branch of epistemology that applies the concepts of biological evolution to the growth of animal and human cognition. It argues that the mind is in part genetically determined and that its structure and function reflect adaptation, a nonteleological process of interaction between the organism and its environment. A cognitive trait tending to increase inclusive fitness in a given population should therefore grow more common over time, and a trait tending to prevent its carriers from passing on their genes should show up less and less frequently.
"Evolutionary epistemology" can also refer to a theory that applies the concepts of biological evolution to the growth of human knowledge, and argues that units of knowledge themselves, particularly scientific theories, evolve according to selection. In this case, a theory—like the germ theory of disease—becomes more or less credible according to changes in the body of knowledge surrounding it.
One of the hallmarks of evolutionary epistemology is the notion that empirical testing alone does not justify the pragmatic value of scientific theories, but rather that social and methodological processes select those theories with the closest "fit" to a given problem. The mere fact that a theory has survived the most rigorous empirical tests available does not, in the calculus of probability, predict its ability to survive future testing. Karl Popper used Newtonian physics as an example of a body of theories so thoroughly confirmed by testing as to be considered unassailable, but which were nevertheless overturned by Einstein's bold insights into the nature of space-time. For the evolutionary epistemologist, all theories are true only provisionally, regardless of the degree of empirical testing they have survived.