Part 4/11:

Alfred Wallace, after an extensive expedition through the Malay Archipelago in the mid-1800s, was the first to uncover the distinct differences in the flora and fauna across the Wallace Line. While previously, observations had been made on the varied nature of neighboring islands, Wallace's meticulous collection of over 125,000 specimens provided concrete evidence that led to the formulation of biogeography—a theory that highlights how geography impacts biological distribution.