Oulie
Alfred Russel Wallace
Photo: London Stereoscopic and Photographic Company (active 1855-1922), Public domain, via Wikimedia Commons

Alfred Russel Wallace

Alfred Russel Wallace was an English naturalist, explorer, geographer, anthropologist and illustrator. He independently conceived the theory of evolution through natural selection; his 1858 paper on the subject was published that year alongside extracts from Charles Darwin's writings on the topic. It spurred Darwin to set aside the "big species book" he was drafting and to quickly write an abstract of it, which was published in 1859 as On the Origin of Species.

Excerpt from Wikipedia, available under CC BY-SA 4.0.

Books