Alfred Russel Wallace

Alfred Russel Wallace (1823-1913), British naturalist, who independently developed a theory of evolution by natural selection contemporaneously with Charles Darwin. Wallace’s work provided a spur for Darwin’s publication of The Origin of Species (1859) following a joint paper presented to the Linnean Society of London in 1858. Wallace is also regarded as one of the founders of modern biogeography—the study of the distribution of flora and fauna over the globe through time with an underlying assumption of the mutability of species.

Wallace’s early education reflected the genteel poverty into which he was born in Monmouthshire, Wales, on January 8, 1823: adequate, but not inspiring. Unlike many naturalists he was not a collector as a child, and from the age of 15 he was apprenticed as a surveyor to his elder brother, William. The outdoor life gradually stimulated an interest in the plants, insects, people, and geological features of the land. In the 1840s he expanded his reading in natural history, geology, and evolution, and began a life-long friendship with Henry Walter Bates, later renowned for his work on mimicry among insects, which Wallace extended in the 1860s to explain polymorphic imitation in species found in the Malay Archipelago (now Malaysia and Indonesia).

Disillusioned with life as a surveyor, Wallace persuaded Bates to accompany him to South America as a professional collector. From 1848 to 1852 Wallace explored the Negro and Uaupés rivers. He amassed a large collection of specimens, the majority of which were lost when the ship in which Wallace was returning home sank. If the South American period had failed to provide the capital to make Wallace independent, he had at least gained both a reputation as a naturalist, and evidence for his growing interest in species, their mutability, and the support that this provided for evolution. He was struck by the boundaries that the immense rivers of the Amazon basin represented, and the presence and differential adaptation of species to be found on each land mass. Evidence of his growing evolutionary thinking can be discerned in Wallace’s successful A Narrative of Travels on the Amazon and Rio Negro (1853).

In 1854, with some assistance from the Royal Geographical Society, Wallace set out for the Malay Archipelago, where he remained until 1862 amassing a collection of 126,000 specimens. In 1858, while recovering from malaria, Wallace re-read an Essay on the Principle of Population by Thomas Malthus and realized that competition for survival would favour those best adapted to their particular situation, and therefore provide a motor for evolution by natural selection. He communicated his preliminary thinking to Charles Darwin by letter. Charles Lyell and Joseph Hooker, whom Darwin consulted, arranged for a joint paper by Darwin and Wallace to be read at the Linnean Society. Wallace was genuinely flattered by the attention of Lyell and Hooker, as well as Darwin, whom he admired and continued to associate with after returning to Britain.

In the 1860s Wallace worked on the collections that formed the basis for the highly successful The Malay Archipelago (1869) and Contributions to the Theory of Natural Selection (1870). In the 1870s he broadened his scope to biogeography with a particular focus on the tropical regions, where he made the observations that led to Island Life (1880), The Geographical Distribution of Animals (1876), and Tropical Nature and other Essays (1878). The zoological dividing line between animal species of Asia and Australia, which he placed between the islands of Borneo and Celebes, is now known as Wallace’s Line. During 1886 and 1887 he undertook a lecture tour of North America, which became the basis for Darwinism (1889), a leading contemporary synthesis of evolutionary biology.

Wallace’s later activities were influenced by his conversion to spiritualism in the 1860s. He is regarded as an original and free thinker whose eclectic interests included phrenology and mesmerism. Wallace supported land nationalization, socialism, the anti-vaccination movement, and rights for women. He was recognized with a civil pension in 1881 and the Order of Merit in 1908. He received many scientific honours: he was elected a Fellow of the Royal Society in 1893 and received the first Darwin-Wallace medal of the Linnean Society in 1908.