Charles Darwin (1809–1882) is easily one of the most influential figures in modern science. His theory of evolution has influenced every scientific discipline involved with living organisms. Prior to the theory of evolution, the variety of life on earth was seen as a product of God’s creation. All creation occurred according to the book of Genesis with no changes since. To suggest that animals had changed over time implied that God’s creation was less than perfect. Thus the theory of evolution challenged Christian theology about the very origins of life.

Because of this, Darwin’s theory was highly controversial in its day. In some circles it remains so today. Scientifically, however, Darwin’s basic premises have never been seriously challenged. Darwin was not the first proponent of a theory of evolution. In fact, his grand father Erasmus Darwin (1731–1802) contributed to early work on the subject. What was missing in Darwin’s day was an exact explanation of the mechanism of evolution and appropriate supporting evidence. Darwin gathered evidence for his theory on his famous sea voyage on the H.M.S. Beagle in 1831, in which he traveled from England to the coast of Africa to the southern tip of South America and back. It took him more than twenty years, though, to synthesize his observations into a coherent theory.

By the time Darwin published his famous essay “On the Origins of Species by Means of Natural Selection” in 1859, the scientific community was ready to receive it. It was an immediate sensation. Darwin’s theory of genetics, however, was not well developed. The monk Gregor Mendel did not publish his study of pea plants until 1866 and his work was not appreciated until the beginning of the twentieth century. The current view of evolution reflects a synthesis of Darwin’s theory of natural selection and Mendelian genetics.