Charles Robert Darwin was born in Shrewsbury, England, on February 12, 1809. He came from a wealthy family and never had to work. He studied medicine and theology. In 1831 he graduated from the University of Cambridge with a degree of theology. He began a career as a scientist quite by chance. On December 27, 1831, 22 years old Charles Darwin joined the crew of the HMS Beagle as a naturalist. The five years expedition collected hydrographic, geologic, and meteorologic data from South America and many other regions around the world. Darwin's own observation on this voyage led to his theory of natural selection. Charles Darwin was greatly influenced by the geologist Adam Sedgwick and naturalist John Henslow in his development of the theory of natural selection, which was to become the foundation concept supporting the theory of evolution. Darwin's theory holds that environmental effects lead to varying degrees of reproductive success in individuals and groups of organisms. Natural selection tends to promote adaptation in organisms when necessary for survival. This revolutionary theory was published in 1859 in Darwin's now famous On the Origin of Species by Means of Natural Selection. Charles Darwin's theory of evolution believed that ...