Final answer:
Evolution by natural selection was independently conceived by Charles Darwin and Alfred Russel Wallace, and they jointly presented their work in 1858. Darwin published 'On the Origin of Species' in 1859, which became the seminal work on the theory.
Step-by-step explanation:
The concept of evolution by natural selection was conceived and described independently by two naturalists, Charles Darwin and Alfred Russel Wallace. In 1858, they jointly presented papers to the Linnean Society in London that introduced their ideas regarding natural selection. The following year, in 1859, Darwin published his seminal work, On the Origin of Species, which detailed his arguments for evolution by natural selection, an idea that he and Wallace had both arrived at independently through their separate expeditions to the tropics. However, it was Darwin's book that thoroughly outlined the theory and is most credited with its popularization.