What primary factor supports the spread of different species within an isolated environment?

Geographic isolation is a crucial factor in the spread and diversification of species within an isolated environment. When groups of organisms are separated by physical barriers—such as mountains, rivers, or distance—they can evolve independently from one another. This isolation prevents gene flow between populations, leading to distinct evolutionary paths. As different pressures are exerted by the environment, such as variations in climate, food sources, or predators, these isolated populations can adapt and diverge over time, resulting in the emergence of new species.

In contrast, while natural habitat restoration and pollination diversity play important roles in ecosystems, they don't primarily drive the initial spread of species like geographic isolation does. Predation factors might influence population dynamics but do not directly relate to species dispersal due to isolation. Thus, geographic isolation stands out as the primary means by which species spread and evolve differently in isolated environments.