|Alfred Russel Wallace|
Alfred Russel Wallace, the English naturalist and coformulator with Charles Darwin of the theory of natural selection, was born at Usk, Monmouthshire. He was largely self-educated, having left school at fourteen to serve as a surveyor’s assistant with his brother. Like many of his contemporaries he acquired an early taste for the study of nature.
But he also read widely and was influenced by the works of Alexander von Humboldt, Thomas Malthus, and Charles Lyell, as Darwin was. In 1844, while teaching school at Leicester, he met the naturalist H. W. Bates (1825–1892), who introduced him to scientific entomology. The two men later embarked on a collecting trip to the Amazon, where Wallace remained for four years examining the tropical flora and fauna.
In 1854, after a brief visit to England,Wallace set out by himself for the Malay Archipelago. He subsequently wrote an account of this trip, The Malay Archipelago (London, 1869),which is a fascinating narrative. When he returned in 1862, he had become a convinced evolutionist and was known in scientific circles for his formulation of the theory of natural selection.
Another of his scientific contributions was “Wallace’s line,” a zoogeographical boundary he drew in 1863 to separate Indian and Australian faunal regions, and which was assumed to pass through the middle of the archipelago.
The rest of Wallace’s long life was spent in England, except for a lecture tour of the United States in 1887 and short visits to the Continent. Darwin, Lyell, Thomas Henry Huxley, John Tyndall, and Herbert Spencer were among his most intimate friends.
He wrote extensively on a wide variety of subjects, but biological interests remained central to his outlook and are reflected in such books as The Geographical Distribution of Animals (London and New York, 1876), Darwinism (London and New York, 1889), Man’s Place in the Universe (London and New York, 1903), and The World of Life (London and New York, 1910).
Wallace first thought of the theory of natural selection in February 1858, when he was ill with a fever at Ternate in the Moluccas. The occasion gave him time to reflect on the mechanism by which species might be altered.
He outlined the theory rapidly in a paper, “On the Tendency of Varieties to Depart Indefinitely from the Original Type,” and sent it to Darwin, who saw that Wallace had hit upon exactly the theory that he himself had formed and privately written down in 1842.
With characteristic generosity he proposed that Wallace’s outline should be published immediately. Lyell, however, urged a compromise that resulted in a joint communication from Darwin and Wallace that was read at the Linnaean Society on July 1, 1858. The two men thus received equal credit for the new doctrine, although Darwin was actually the pioneer.
The joint communication created no stir at the meeting. However, it was later clearly recognized as a revolutionary document that demolished forever the ancient idea of the fixity of species by formulating a scientific theory of how species change and how their adaptations are secured at each stage of the process.
When Darwin published his famous books, the accord between him and Wallace began to disappear. The view expressed in The Origin of Species that evolution required the operation of factors of a Lamarckian as well as of a selective sort was unacceptable to Wallace. For him “natural selection is supreme” and is the sole means of modification, except in the case of man.
Hence he became, like August Weissmann, an apostle of neo-Darwinism. This led him to hold that every phenotypic character of an organism must be useful to that organism in the struggle for life; the principle of utility is of universal application.
With regard to human evolution Wallace differed from Darwin in affirming that man’s mental powers, especially “the mathematical, musical and artistic faculties,” have not been developed under the law of natural selection.
These faculties point to the existence in man of something that he has not derived from his animal progenitors, “something which we may best refer to as being of a spiritual essence.” It came into action when man appeared on the evolutionary stage.
As he grew older, Wallace put more and more emphasis on the spiritual agency, so that in The World of Life it is described as “a Mind not only adequate to direct and regulate all the forces at work in living organisms, but also the more fundamental forces of the whole material universe.” For many years Wallace was interested in spiritualism and psychical research.
A pamphlet that he published in 1866, The Scientific Aspect of the Supernatural, discussed such matters as clairvoyance, apparitions, animal magnetism, and the problem of miracles. It was clear that he took them seriously, and they influenced his general outlook. All this was far removed from anything Darwin was prepared to countenance.
Apart from the theory of natural selection,Wallace’s most enduring work was his Geographical Distribution of Animals. He also made acute judgments on anthropological matters, such as the evolutionary significance of the human brain and human intelligence.
Thus he contended that the brain is a specialized organ that has freed man from the dangers of specialization by vastly increasing his adaptability and that man’s intelligence has allowed him to evolve without undergoing major somatic changes.
Yet despite Wallace’s fertility in producing ideas and his command of a wide array of facts, he never quite succeeded in relating the two. His ideas were not carefully analyzed or tested. At bottom he was a naturalist, with a deep love of nature and an inexhaustible passion for collecting.