The English naturalist and traveler Alfred Russel Wallace (1823-1913), independently of Darwin, discerned the mechanism of evolution by natural selection.

Alfred Russel Wallace, the eighth of nine children, was born on Jan. 8, 1823, at Usk, Monmouthshire. He was educated at Hertford Grammar school and left at the age of 14. He learned surveying and some geology from his brother William.

In 1844 Wallace became a schoolmaster at the Collegiate School in Leicester, where he met the naturalist Henry Bates. Wallace convinced Bates to join him on an expedition to the Amazon to collect specimens. They sailed in April 1848; by March 1850 they separated so as to exploit wider collecting grounds. Wallace sailed for England in 1852; his specimens were lost when the ship was destroyed by fire. He reported on his findings in Travels on the Amazon and Rio Negro and Palm Trees of the Amazon (both 1853).

In 1854 Wallace was given a government...