Charles Darwin is most remembered today for his contribution to the theory of evolution through natural selection.
The seeds of this theory were sown in Darwin’s mind through observations made during a five-year voyage across the New World on a ship called the Beagle. There he studied fossils and geological records, the geographical distribution of organisms, the uniqueness and relationship of island life forms, and the affinity of island forms to continental forms. Upon returning to England, Darwin reflected on his observations and concluded that evolution must be by natural selection. However, he refused to publish his work due to its controversial nature.
However, when another scientist, Wallace, came to similar conclusions, Darwin was persuaded in 1859 to publish his observations. His hypothesis revolutionized biology and has yet to be refuted by the empirical data of leading scientists.