“Two Distinct Creators”: Comparing Darwin’s and Wallace’s Formative Travels, and How it Influenced their Theory of Evolution

Charles Darwin and Alfred Russel Wallace independently arrived at similar theories of evolution by natural selection as announced in 1858. Both men had undertaken transformative travels that provided data for their conclusions. This article compares and contrasts their published travel narratives and shows how it impacted their interpretations. While Darwin’s voyage aboard the H.M.S. Beagle (1831-1836) was largely in the southern hemisphere temperate zone, Wallace’s (1854-1862) island-hopping expedition was confined to the Malayan (Indonesian) Archipelago. Although very similar, there were slight differences in their resulting theories of natural selection. The debates that would divide them on this issue related especially to sexual dimorphism in birds and butterflies, with examples from their travels. Both men, however, perceived the profound differences between the Australian fauna and that of the rest of the world. Wallace was able to identify the exact boundary between these two different “creations,” later dubbed “Wallace’s Line.”