The [[theory of natural selection]] is one of two major evolutionary theories advanced by Darwin, the other being the [[theory of descent with modification]].<ref> [http://www.newworldencyclopedia.org/entry/Darwinism]</ref> | The [[theory of natural selection]] is one of two major evolutionary theories advanced by Darwin, the other being the [[theory of descent with modification]].<ref> [http://www.newworldencyclopedia.org/entry/Darwinism]</ref> |