Geographic isolation occurs when a population of organisms is separated from others of the same species by physical barriers, such as mountains, rivers, or oceans. This separation can prevent individuals from mating and exchanging genetic material, leading to distinct evolutionary paths over time. As a result of geographic isolation, unique species can develop in different regions. For example, the Galápagos Islands are famous for their diverse wildlife, including the Galápagos tortoise, which evolved separately from mainland species due to isolation. This process contributes to biodiversity and can lead to the formation of new species.