Wallace Line Wallace Line 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 English biologist Thomas Henry Huxley, that separates the ecozones of Asia and Wallacea, a transitional zone between Asia and Australia. West of the line are found organisms related to Asiatic species; to the east, a mixture of species of Asian and Australian origin is present. Wallace noticed this clear division during his travels through the East Indies in the 19th century. The line runs through Indonesia, between Borneo and Sulawesi (Celebes), and through the
Wallace Line Lombok Strait between Bali and Lombok. The distance between Bali and Lombok is small, about . The distributions of many bird species observe the line, since many birds do not cross even the shortest stretches of open ocean water. Some bats have distributions that cross the line, but larger terrestrial mammals are generally limited to one side or the other; exceptions include macaques, pigs and tarsiers on Sulawesi. Other groups of plants and animals show differing patterns, but the overall pattern is striking and reasonably consistent. Flora do not follow the Wallace Line to the same extent as fauna. One