Alfred Russel Wallace OM FRS (8 January 1823  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; his paper on the subject was jointly published with some of Charles Darwin's writings in 1858. This prompted 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 faunal divide now termed the Wallace Line, which separates 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 fauna reflect Australasia. Wallace was a prolific author who wrote on both scientific and social issues; his account of his adventures and observations during his explorations in Singapore, Indonesia and Malaysia, The Malay Archipelago, is regarded as probably the best of all journals of scientific exploration published during the 19th century.