Alfred Russel Wallace, OM, FRS (8 January – 7 November 1913) was a British naturalist, explorer, geographer, anthropologist and biologist. He is best known for independently conceiving the theory of evolution through natural selection, which prompted Charles Darwin to publish his own ideas in On the Origin of Species. Wallace did extensive fieldwork, first in the Amazon River basin and then in the Malay Archipelago, where he identified the Wallace Line that divides the Indonesian archipelago into two distinct parts, a western portion in which the animals are largely of Asian origin, and an eastern portion where the birds and mammals are more similar to those of Australia. He was considered the 19th century's leading expert on the geographical distribution of animal species and is sometimes called the "father of biogeography". Wallace was one of the leading evolutionary thinkers of the 19th century and made many other contributions to the development of evolutionary theory besides being co-discoverer of natural selection. These included the concept of warning colouration in animals, and the Wallace effect, a hypothesis on how natural selection could contribute to speciation by encouraging the development of barriers against hybridization.
[Telegraph.co.uk] - Although Darwin is the most familiar name associated with evolution, he was only persuaded to publish his work when another young scientist, Alfred Russel Wallace, came forward having independently come up with a similar explanation for how evolution