Title page of Darwin's "On The Origin Of Species By Means of Natural Selection", 1859. In this book, Darwin suggested that natural variation in a species creates a wide range of individual characteristics. Competition to survive in nature provides a driving force for evolution in the form of natural selection, a mechanism which weeds out those individuals possessing traits less suitable to the environment. The implications of his theory to man's own origins fueled a bitter controversy with the church. Charles Robert Darwin (February 12, 1809 - April 19, 1882) was an English naturalist, geologist and biologist. Puzzled by the geographical distribution of wildlife and fossils he collected on the five-year voyage on HMS Beagle, Darwin began detailed investigations and in 1838 conceived his theory of natural selection. He was writing up his theory in 1858 when Alfred Russel Wallace sent him an essay that described the same idea, prompting immediate joint publication of both of their theories. In 1871 he examined human evolution and sexual selection in The Descent of Man, and Selection in Relation to Sex, followed by The Expression of the Emotions in Man and Animals (1872). Darwin has been described as one of the most influential figures in human history. He died in 1882, at the age of 73, and he was honored by burial in Westminster Abbey.