Charles Darwin did not invent anything though he discovered a lot as a scientist and naturalist, and as an author he impacted science and the way we think about our world. He also developed and proposed a theory about evolution. His theory has had far reaching effects on science and the way we understand life. Darwin’s most important observation on the H.M.S. Beagle was the amount of difference that existed within animal species living on the Galapagos islands.