Alfred Russel Wallace (January 8, 1823-November 7, 1913) was a British naturalist and biologist. His work on the theory of natural selection influenced Charles Darwin.
Wallace was born at Usk, Monmouthshire. He attended grammar school in Hertford, but left when his family lost their remaining property. He worked for his older brother William in his surveying business, and between 1840 and 1843 spent his time surveying in the west of England and Wales. In 1844 he was hired as a master at the Collegiate School in Leicester. In 1845 his brother William died and Wallace returned to run the surveying business.
In 1848, Wallace together with another naturalist, Henry Walter Bates (whom he met in Leicester), left for Brazil to collect specimens in the Amazon Rainforest. Unfortunately, a large part of his collection got annihilated when his ship caught fire on return to Britain in 1852.
From 1854 to 1862, he travelled through the "Malay Archipelago" or East Indies (now Malaysia and Indonesia), to collect specimens and study nature. One of his better known discoveries here is the gliding tree frog Rhacophorus nigropalmatus, Wallace's flying frog.
His studies, eventually published in 1869 as The Malay Archipelago, included the key influence of Thomas Malthus' Essay on the Principle of Population, and led to his independent arrival at a theory of evolution similar to that of Charles Darwin. Darwin at that time had not published his theory, but when Wallace sent him an essay concerning his theory, "On the Tendency of Varieties to Depart Indefinitely From the Original Type" (1858), Charles Lyell and Joseph Hooker advised Darwin that he should publish his own thoughts at the same time. On July 1, 1858, both papers were presented to the Linnean Society of London. Wallace was the first to propose a "geography" of animal species, and as such is considered one of the precursors of ecology and biogeography.
Among the many awards presented to Wallace were the Order of Merit (1908), the Royal Society's Copley Medal (1908), the Royal Geographical Society's Founder's Medal (1892) and the Linnean Society's Gold Medal (1892).
The Wallace Line
Wallace noted that a line seemed to run through the Malay Archipelago, between Borneo and the Celebes and east of Bali. This line, which is now known as the Wallace Line separates the continents of Asia and Australia zoologically. West of the line are found mostly species that are related to Asiatic species, to the east mostly species that are related to Australian species.
In the mid-20th century, geological studies of plate tectonics showed there is an Indo-Australian plate that has the Wallace Line as a boundary, resulting in a large drop in the sea floor at precisely the same point. This means that it has never been possible for a land bridge to form in the region, hence the zoological distribution.
One interesting note is that many (but by no means all) bird species also observe the line, as many birds refuse to cross even the smallest stretches of open water.