Merriam-Webster Collegiate Dictionary - darwinism

 noun  Date: 1864  1. a theory of the origin and perpetuation of new species of animals and plants that offspring of a given organism vary, that natural selection favors the survival of some of these variations over others, that new species have arisen and may continue to arise by these processes, and that widely divergent groups of plants and animals have arisen from the same ancestors — compare evolution 4, neo-~  2. a theory that inherent dynamic forces allow only the fittest persons or organizations to prosper in a competitive environment or situation economic ~ — compare social ~  • Darwinist noun or adjective