Darwinism is the concept of organic evolution, from a common ancestor, by means of natural selection. The theory was popularized by its namesake, English naturalist Charles Robert Darwin (1809-1882). Darwin's theory first appeared in his book, On the Origin of Species in 1859. Later, Darwin expanded his evolutionary model to include humans. He discussed the scientific importance of man's antiquity in his other major work, The Descent of Man.

Darwin was not the first scientist to propose a theory of evolution. Even Darwin's own grandfather, English physician and naturalist Erasmus Darwin (1731-1802), gained fame for this theories of organic development. Relying on much of the pioneering work of his contemporaries in the fields of geology and biology, and upon his own observations of animal populations he made while circumnavigation the globe as ship's naturalist aboard the H.M.S. BeagleDarwin set forth to explain the inter-linking of all...