Henry Walter Bates, Wallace's early mentor, was a naturalist and explorer whose work on animal mimicry (the imitation of other life forms or inanimate objects by a particular species) backed up Darwin's theory of evolution. Bates introduced Wallace to entomology and travelled with him to explore the Amazon and collect data there.
Sir Joseph Hooker was an internationally renowned botanist and Director of the Royal Botanical Gardens at Kew until 1885. He was a close friend of Charles Darwin and often advised A.R. Wallace.
Thomas Huxley, like Hooker, was a close companion of Charles Darwin. He became known as "Darwin's Bulldog" as a result of his strong advocacy of Darwin's theories. He also served as President of the Royal Society.