Over the years evolutionary theory has itself evolved to encompass new and more disciplines: social Darwinism, genetic algorithms, co-evolution of biology and culture, evolutionary psychology, economics, psychoanalysis, and more. Attempts to formalize evolution typically have focused on several elements or preconditions for natural selection:

1. a POPULATION of individual agents
2. a REPRODUCTION mechanism
3. a MUTATION mechanism that yields differential fitness of agents
4. a SELECTION mechanism which favors highly fit agents over others for reproduction