DARWIN, CHARLES ROBERT English naturalist, author of the Origin of Species, was born at Shrews bury on Feb. 12, 1809, the grandson of Dr. Erasmus Darwin (q.v.). His mother, a daughter of Josiah Wedgwood (1730– '795), died in 1817. Charles's elder brother, Erasmus Alvey (1804-81), was interested in literature and art rather than sci ence: on the subject of the wide difference between the brothers Charles wrote that he was "inclined to agree with Francis Galton in believing that education and environment produce only a small effect on the mind of anyone, and that most of our qualities are innate" (Life and Letters, London, 1887). Darwin considered that his own success was chiefly due to "the love of science, un bounded patience in long reflecting over any subject, industry in observing and collecting facts, and a fair share of invention as well as of common sense" (ibid.). He also says : "I have steadily endeavoured to keep my mind free so as to give up any hypothesis, however much beloved (and I cannot resist forming one on every subject), as soon as facts are shown to be opposed to it" (ibid.). The essential causes of his success are to be found in this latter sentence, the creative genius ever inspired by exist ing knowledge to build hypotheses by whose aid further knowl edge could be won, the calm unbiassed mind, the love of truth which enabled him to abandon or to modify his own creations when they ceased to be supported by observation. The great naturalist appeared in the ripeness of time, when the world was ready for his splendid generalizations. In the preparation for Darwin Sir Charles Lyell's Principles of Geology played an im portant part, accustoming men's minds to the vast changes brought about by natural processes, and leading them, by its lucid and temperate discussion of Lamarck's and other views, to reflect upon evolution.
' Darwin studied at Shrewsbury School under Dr. Samuel Butler (1774-1839), and in 1825 went to Edinburgh to prepare for the medical profession, for which he was unfitted by nature. In 1828 his father sent him to Christ's College, Cambridge with the idea that he should become a clergyman. He took his degree in 1831, tenth in the list of those who do not seek honours. Both at Edinburgh and at Cambridge he gained the friendship of, older scientific men—Robert Edmond Grant and William Mac gillivray at the former, John Stevens Henslow and Adam Sedg wick at the latter. From Dec. 1831 to Oct. 1836, Darwin was on the "Beagle" as naturalist for the surveying expedition. After visiting the Cape de Verde and other Atlantic islands, the ex pedition surveyed on the South American coasts and adjacent islands (including the Galapagos), afterwards visiting Tahiti, New Zealand, Australia, Tasmania, Keeling Island. Maldives, Mauritius, St. Helena, Ascension, and Brazil, de Verdes and Azores on the way home. His work on the geology of these countries and that on coral islands became the subject of volumes which he published after his return, as well as his Journal of a Naturalist, and his other contributions to the official narrative. The voyage was the real preparation for his life-work. His ob servations on the relation between animals in islands and those of the nearest continent and between living animals and those most recently extinct and found fossil in the same country, related but not the same, led him to reflect upon the modification of species. He had also been much impressed by "the manner in which closely allied animals replace one another in proceeding southwards" in South America. His pocket-book for 1837 con tains the words : "In July opened first note-book on Transmuta tion of Species. Had been greatly struck from about the month of previous March [while still on the voyage and just over twenty-eight years old] on character of South American fossils, and species on Galapagos Archipelago. These facts (especially latter) origin of all my views." From 1838 to 1841 he was secre tary of the Geological society, and saw a great deal of Sir Charles Lyell, to whom he dedicated the second edition of his Journal. In Jan. 1839 he married his cousin, Emma Wedgwood. They lived in London until 1842, when they moved to Down, which was Darwin's home for the rest of his life. From 1846 to 1854 he was chiefly engaged upon four monographs on the recent and fossil cirripede Crustacea (Ray Soc., 1851 and 1854; Palaeontograph. Soc., 1851 and 18J4).
Soon after opening his note-book in 1837 he began to collect facts bearing upon the formation of the breeds of domestic animals and plants, and quickly saw "that selection was the key stone of man's success. But how selection could be applied to organisms living in a state of nature remained for some time a mystery to me." Various ideas as to the causes of evolution had to be successively abandoned. He had the idea of "laws of change" which affected species and finally led to their extinction, to some extent analogous to the causes which bring about the development, maturity and finally death of an individual. He also had the conception that species must give rise to other species or else die out, just as an individual dies unrepresented if it bears no offspring. In Oct. 1838 he read Malthus on Population, and his observations having long since convinced him of the struggle for existence, it at once struck him "that under these circum stances favourable variations would tend to be preserved, and unfavourable ones to be destroyed. The result of this would be the formation of new species. Here, then, I had a theory by which to work." In June 1842 he wrote out a sketch, which in 1844 he expanded to an essay of 231 pages folio. The idea of progressive divergence as an advantage in itself, because the competition is most severe between organisms most closely re lated, did not occur to him until long after. In Jan. 1844 he wrote to his friend, Sir Joseph Hooker: "At last gleams of light have come, and I am almost convinced (quite contrary to the opinion I started with) that species are not (it is like confessing a mur der) immutable" (ibid., ii. 13). In 1857 he explained his views to the great American botanist Asa Gray in a letter which afterwards became classical. He had completed about half of a third and far more expanded treatise, when, in June 1858, he received a manuscript from A. R. Wallace, who was then at Ternate in the Moluccas. Wallace wanted Darwin's opinion on the manuscript, which he asked should be forwarded to Lyell. Darwin was much startled to find in the essay a complete abstract of his own theory of natural selection. He wrote to Lyell, "your words have come true with a vengeance—that I should be forestalled." He placed himself in the hands of Lyell and Hooker, who decided to send Wallace's essay to the Linnean society, together with an abstract of Darwin's work, which they asked him to prepare, the joint essay being accompanied by an explanatory letter to the secretary. The title of the joint communication was "On the Tendency of Species to form Varieties; and on the Perpetuation of Varieties and Species by Natural Means of Selection." It was read on July 1, 1858, and appears in the Linn. Soc. Journal (Zoology) for that year. In this statement of the theory of natural selection, Darwin's part consisted of two sections, the first being extracts from his 1844 essay, including a brief account of sexual selection, and the second an abstract of his letter to Asa Gray dated Sept. 5, 1857. Canon H. B. Tristram was the first to apply the new theory, explaining by its aid the colours of desert birds, etc. (Ibis, Oct. 1859).
Acting under the advice of Lyell and Hooker, Darwin published on Nov. 24, 1859, his great work, On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life. The whole edition of 1,25o copies was exhausted on the day of issue. The first four chapters explain the operation of artificial selection by man and of natural selec tion in consequence of the struggle for existence. The fifth chap ter deals with the laws of variation and causes of modification other than natural selection. The five succeeding chapters con sider difficulties in the way of a belief in evolution generally as well as in natural selection. The three remaining chapters (omit ting the final recapitulation), deal with the evidence for evolution. The theory which suggested a cause of evolution is thus given the foremost place and the evidence for the existence of evolution considered last. This evidence had never been thought out and marshalled in a manner which bears any comparison with that of Darwin, and the work would have been epoch-making had it con sisted of the later chapters alone. A storm of controversy arose over the book, reaching its height at the British Association at Oxford in 186o, when the celebrated duel between T. H. Huxley and Bishop Wilberforce of Oxford took place. Throughout these struggles Huxley was the foremost champion for evolution and for fair play to natural selection, although he never entirely ac cepted the latter theory, holding that until man by his selection had made his domestic breeds sterile inter se, there was no suf ficient evidence that selection accounts for natural species which are thus separated by the barrier of sterility.
The Variation of Animals and Plants under Domestication. —Probably the second in importance of Darwin's works was published in 1868, and may be looked upon as a complete account of the material condensed in the first chapter of the Origin. He finally brought together an immense number of apparently dis connected sets of observations under his "provisional hypoth esis of pangenesis," which assumes that every cell in the body, at every stage of growth and in maturity, is represented in each germ-cell by a gemmule. The germ-cell is only the meeting-place of gemmules, and the true reproductive power lies in the whole of the body-cells which despatch their representatives, hence "pangenesis." There are reasons for believing that this infinitely complex conception, in which, as his letters show, he had great confidence, was forced upon Darwin in order to explain the heredi tary transmission of acquired characters involved in the small proportion of Lamarckian doctrine which he incorporated. If such transmission does not occur, a simpler hypothesis based on the lines of Weismann's "continuity of the germ-plasm" is sufficient to account for the facts (see HEREDITY; LAMARCKISM).
The Descent of Man and Selection in Relation to Sex (1871), both fulfilled his statement in the Origin that "light would be thrown on the origin of man and his history," and collected the evidence in support of his hypothesis of sexual selection which he had briefly described in the 1858 essay. The Expression of the Emotions (1872) offered a natural explanation of phenomena which appeared to be a difficulty in the way of the acceptance of evolution. In 1876 Darwin brought out his two previously pub lished geological works on Volcanic Islands and South America as a single volume. The widely read Formation of Vegetable Mould through the Action of ll'orms appeared in 1881 ; and the Fertil ization of Orchids in 1862. The Effects of Cross- and Self-Fertil ization in the Vegetable Kingdom (1876) proved that the off spring of cross-fertilized individuals are more vigorous, as well as more numerous, than those produced by a self-fertilized parent. Different Forms of Flowers on Plants of the Same Species (18 7 7 ) demonstrates that each different form, although possessing both kinds of sexual organs, is specially adapted to be fertilized by the pollen of another form, and that when artificially fertilized by pollen from a plant of its own form, less vigorous offspring are produced. Climbing Plants and Insectivorous Plants were pub lished in 1875, and The Power of Movement in Plants in 1880. Darwin died on April 19, 1882, and was buried in Westminster Abbey on the 26th.
Two daughters and five sons survived him, four of the latter becoming prominent in the scientific world,—Sir George Howard (1845-1912), who became professor of astronomy and experimen tal philosophy at Cambridge ; Sir Francis (1848-1925 ) , distin guished botanist; Leonard (b. 185o), a major in the royal engi neers, and afterwards well known as an economist and eugenist; and Sir Horace (1851-1928), civil engineer.
See Life and Letters of Darwin, including an autobiographical chapter, ed. by his son Francis Darwin (3 vols., 1887) and More Letters (2 vols., 19o3) ; E. B. Poulton, Darwin and the Theory of Natural Selection (1896) and Darwin and the Origin of Species (19o9) ; L. Huxley, Life and Letters of T. H. Huxley (2 vols., 190o) and Charles Darwin (1921) ; V. L. Kellog, Darwinism To-day (19o7) ; J. Marchant, A. R. Wallace, Letters, etc. (2 vols., 1916) and H. Ward, C. Darwin (1927). See also HUXLEY, T. H., WALLACE, A. R. and HOOKER, SIR JosErH. (E. B. Po.)