The British naturalist Alfred Russel Wallace (1823-1913) is best known for independently proposing a theory of evolution due to natural selection that prompted Charles Darwin to publish his own theory.  Wallace worked extensively in the field, first in the Amazon River basin and then in the Malay Archipelago, where he identified the ecological line (which came to be known as Wallace's Line) that divides the Indonesian archipelago into two distinct parts, one in which animals closely related to those of Australia are common, and one in which the species are largely of Asian origin.  He was considered the 19th century's leading authority on the geographical distribution of animal species and has been called the "father of biogeography".