Charles Darwin proposed the theory of evolution through natural selection. His book, On the Origin of the Species offered extensive documentation of natural selection as the main vehicle for biological evolution.
Much of his work and research was conducted along the coast of South America, including the famous Galapagos Islands.

Wallace, working on his own, also concluded that natural selection was the means through which biological evolution occurred.
Much of his work and research was conducted along the Amazon River and in the Malay Archipelago - the island chain between Indochina and Australia.