ˈdärwə̇ˌnizəm, ˈdȧw- noun
( -s )
Usage: usually capitalized
Etymology: C. R. Darwin, its promulgator + English -ism
: the theory of the origin and perpetuation of new species of animals and plants holding that organisms tend to produce offspring varying slightly from their parents, that the process of natural selection tends to favor the survival of individuals whose peculiarities render them best adapted to their environment, and that chiefly by the continued operation of these factors new species not only have been and may still be produced but organisms of widely differing groups may have arisen from common ancestors ; broadly : biological evolutionism — compare evolution 5b, neo-darwinism ; lamarckism , mutation