Darwin, Charles Robert (1809–1882)

The theory of evolution which Darwin first expressed in The Origin of Species resulted from his discoveries while naturalist on board the Beagle when he was in his early 20s. Charles Robert Darwin spent the rest of his life studying the results of that expedition, and formulating his theory of the evolutionary process.

A portrait of the English naturalist Charles Darwin, copy by John Collier (1850–1934) in the National Portrait Gallery, London. As the originator of the theory of evolution based on the concept of natural selection, Darwin's publication of his famous treatise The Origin of Species (1859) aroused considerable opposition, mainly from the church, and led to an historic debate at Oxford in 1860 on whether man was descended from ‘apes or angels’.

English naturalist who developed the modern theory of evolution and proposed, with Welsh naturalist Alfred Russel Wallace, the principle of natural selection. After research in South America and the Galapagos Islands as naturalist on HMS Beagle (1831–36), Darwin published On the Origin of Species by Means of Natural Selection or the Preservation of Favoured Races in the Struggle for Life (1859). This book explained the evolutionary process through the principles of natural selection and aroused widespread argument and debate among scientists and religious leaders because it disagreed with the literal interpretation of the Book of Genesis in the Bible.

Darwin was born in Shrewsbury, the grandson of Erasmus Darwin, and studied medicine at Edinburgh and theology at Cambridge. His theory of natural selection concerned the differences existing between members of a sexually reproducing population. Those members with characteristics better fitted to the environment in which they lived would be more likely to survive and breed than other members, subsequently passing on these favourable characteristics to their young. He avoided the issue of human evolution, however, remarking at the end of The Origin of Species that ‘much light will be thrown on the origin of man and his history’. It was not until his publication of The Descent of Man and Selection in Relation to Sex (1871), that Darwin argued that people evolved just like other living organisms. He did not seek the controversy he caused but his ideas soon caught the public imagination. The popular press soon published articles about the ‘missing link’ between humans and apes. Darwin's view was that when females or males choose to mate they are applying a form of natural selection that would result in evolution. Until fairly recently, this part of Darwin's theory was not widely supported by biologists, but now has some following.

Origin of Darwin's theories Darwin's work marked a turning point in many of the sciences, including physical anthropology (study of the development of the human race) and palaeontology (study of fossils). But, before the voyage of the Beagle, Darwin, like everyone else at that time, did not believe in the mutability of species (the theory that animals and plants could change and adapt over time to their surroundings). Acceptance of the mutability of species would challenge the teachings of the Bible that God created the Earth and the creatures on it. In South America, Darwin saw fossil remains of giant sloths and other animals now extinct, and on the Galapagos Islands he found a colony of finches that he could divide into at least 14 similar species, none of which existed on the mainland. It was obvious to him that one type must have made the long journey from South America and evolved into many others, but Darwin was unable to explain how this had happened. Two years after his return he read ‘An Essay on the Principle of Population’ (1798) by English economist Thomas Malthus, which proposed that the human population was growing too fast for it to be adequately fed, and that something would have to reduce it, such as war or natural disaster. This work inspired Darwin to see that the same principle could be applied to animal populations.

On the Origin of Species also rejected earlier evolutionary theories, such as those of French naturalist J B de Lamarck. Lamarck's view was that structures that changed during the life of an organism would remain changed in its offspring. For example, Lamarck would have believed that a giraffe may stretch its neck to reach leaves and produce offspring with longer necks. Darwin's view was that there would be differences between individual giraffes, and that some would have longer necks. If the climate changed and food was reduced, the giraffes which inherited the characteristic of longer necks would survive to reproduce more than those with shorter necks.

Reaction The significance of Darwin's work could not be ignored. The 19th century was still an age where religion was an all-dominating force in society. God's creation of the world and its creatures in six days, as stated in the Book of Genesis, was taken as fact, while his creation of Adam and Eve was believed to be the origin of the human race. The idea that animals and humans had evolved or changed over millions of years challenged the basic foundations of Christian teaching. The suggested process of evolution involved improvements in species, implying that God had not created the perfect creature. In addition to this, the Christian faith gave humans a special place in the world, superior to all other living things. If humans, like animals, were the result of evolution, this special position was denied.

Darwin's theories were also opposed by many botanists. As he could not completely prove his theories, many rejected them as fanciful nonsense, so far removed from standard ideas as to be unbelievable. Darwin himself played little part in the debates, but his Descent of Man (1871) added fuel to the theological discussion, in which English scientist T H Huxley and German zoologist Ernst Haeckel took leading parts.

Early work and other research Darwin's first book was Journal of Researches into the Geology and Natural History of the Various Countries Visited by HMS Beagle (1839). By 1844 he had enlarged his sketch of ideas to an essay of his conclusions, but remained cautious about its publication. However, in 1858 he was forced into action when he received a memoir from Alfred Russel Wallace, containing the same theory of evolution.

Darwin also made important discoveries in many other areas, including the fertilization mechanisms of plants, the classification of barnacles, and the formation of coral reefs. He was the first to propose a link between coral reefs and volcanic islands. His ideas remain the primary theory of atoll growth formation, explaining how ring-shaped coral islands developed.

Gregor Mendel Darwin never understood what caused newly formed advantageous characteristics to appear in animals and plants because he had no knowledge of heredity and mutations. The irony is that the key work on heredity by the Austrian scientist Gregor Mendel was carried out during Darwin's own lifetime and published in 1865, but was neglected until 1900. Neo-Darwinism, the current theory of evolution, is a synthesis of Darwin's theories and genetics based on Mendel's work.