The famous British naturalist who developed the theory of evolution through natural selection is Charles Darwin. His landmark work, "On the Origin of Species", published in 1859, provided compelling evidence for evolution and changed the course of biological sciences. Darwin's observations during his voyage on the HMS Beagle led him to propose that species evolve over time through the process of adaptation to their environments, challenging traditional notions of creationism and sparking significant discussions in both scientific and religious communities.