<P> Darwinism is a theory of biological evolution developed by the English naturalist Charles Darwin (1809--1882) and others, stating that all species of organisms arise and develop through the natural selection of small, inherited variations that increase the individual's ability to compete, survive, and reproduce . Also called Darwinian theory, it originally included the broad concepts of transmutation of species or of evolution which gained general scientific acceptance after Darwin published On the Origin of Species in 1859, including concepts which predated Darwin's theories . It subsequently referred to the specific concepts of natural selection, the Weismann barrier, or the central dogma of molecular biology . Though the term usually refers strictly to biological evolution, creationists have appropriated it to refer to the origin of life, and it has even been applied to concepts of cosmic evolution, both of which have no connection to Darwin's work . It is therefore considered the belief and acceptance of Darwin's and of his predecessors' work--in place of other theories, including divine design and extraterrestrial origins . </P> <P> English biologist Thomas Henry Huxley coined the term Darwinism in April 1860 . It was used to describe evolutionary concepts in general, including earlier concepts published by English philosopher Herbert Spencer . Many of the proponents of Darwinism at that time, including Huxley, had reservations about the significance of natural selection, and Darwin himself gave credence to what was later called Lamarckism . The strict neo-Darwinism of German evolutionary biologist August Weismann gained few supporters in the late 19th century . During the approximate period of the 1880s to about 1920, sometimes called "the eclipse of Darwinism," scientists proposed various alternative evolutionary mechanisms which eventually proved untenable . The development of the modern synthesis in the early 20th century, incorporating natural selection with population genetics and Mendelian genetics, revived Darwinism in an updated form . </P>

What is the main premise of darwinian evolution