![]() ![]() Those caused the isolation of different taxonomic groups on islands at present relatively close to each other. The complex biogeography of the Indo-Australian Archipelago is a result of its location at the merging point of four major tectonic plates and other semi-isolated microplates in combination with ancient sea levels. The line runs through Indonesia, between Borneo and Sulawesi (Celebes), and through the Lombok Strait between Bali and Lombok, where the distance is strikingly small, only about 35 kilometers (22 mi), but enough for a contrast in species present on each island. Wallace noticed this clear division in both land mammals and birds during his travels through the East Indies in the 19th century. To the west of the line are found organisms related to Asiatic species to the east, a mixture of species of Asian and Australian origins is present. Huxley that separates the biogeographical realms of Asia and ' Wallacea', a transitional zone between Asia and Australia also called the Malay Archipelago and the Indo-Australian Archipelago. The Wallace line or Wallace's line is a faunal boundary line drawn in 1859 by the British naturalist Alfred Russel Wallace and named by the English biologist T.H. The deep water of the Lombok Strait between Bali and Lombok formed a water barrier even when lower sea levels linked the now-separated islands and landmasses on either side. The probable extent of land at the time of the Last Glacial Maximum, when the sea level was more than 110 m (360 ft) lower than today, is shown in grey. He died at the age of 90 in 1913.Wallace's Line delineates Australian and Southeast Asian fauna. He wrote a wide variety of works and wide variety of topics, and toured the United States lecturing. Wallace would become one of England's most well known naturalists. Wallace also foresaw the dangers that deforestation would wrought if not brought to heel, writing that extensive deforestation could degrade the soil of countries like India and impact the population therein by contributing to famines and greater natural disasters. Darwin emphasized individual competition and the "struggle for life" as the main selective factor involved in evolution, while Wallace emphasized environmental pressures instead. Wallace was a good sport about it all, though, and even published a book defending Darwin.Īlthough Darwin and Wallace had a similar idea of natural selection, key differences remained. He also became a spiritualist in the late 1860s. ![]() Later he expressed doubts about whether human intelligence could be the result of natural selection. Wallace wouldn't return to the subject until 1864. ![]() Wallace's work in the region led to his identification of what Thomas Henry Huxley would later call the Wallace Line, after him. For example, Wallace was in the Malay Archipelago (what is now Indonesia) when he came up with natural selection, dashed off an essay that would ensure his place in history, and then went back to exploring the region. Wallace didn't publish as extensively on natural selection as Darwin did, but he published other things as well. Not wanting to be scooped, Darwin arranged to have both Wallace's paper and some of his own writing presented at a meeting of the Linnean Society without Wallace's permission. In 1858, he sent his essay to Charles Darwin, who realized that Wallace had come up with the same theory of evolution that he had spent 20 years working on. Wallace co-discovered natural selection because he wrote an essay about it on the spur of the moment while suffering from malaria (that must have been some good malaria). ![]()
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