evidence: (1809 – 1882) Developed theory of evolution against a backdrop of disbelief and scepticism. Collected evidence over 20 years, and published conclusions in On the Origin of Species (1859). [...] "I have called this principle, by which each slight variation, if useful, is preserved, by the term Natural Selection" [...] "The expression often used by Mr. Herbert Spencer of the Survival of the Fittest is more accurate, and is sometimes equally convenient"