'On the Origin of Species' (1859), evolutionary diagram. This diagram, the only illustration in the book, depicts the diversification of life from one or more common ancestor. Fourteen generations are shown here, moving from bottom to top. The full title of the book is 'On the Origin of Species by means of Natural Selection, or the preservation of favoured races in the struggle for life'. It was written by British naturalist Charles Darwin (1809-1882). His theory of evolution caused a storm of controversy with Christian orthodoxy, as it contradicted the widely accepted belief that different animal and plant species were created by a divine creator (God).