What does geographical isolation refer to?

Geographical isolation refers to a situation where populations are separated by physical barriers that prevent them from interbreeding. This can occur due to natural features like mountains, rivers, or distances that act as barriers in the environment. When populations are geographically isolated, they can experience divergent evolutionary paths, which may lead to speciation over time as genetic material does not flow between them.

In contrast, behavioral differences primarily involve reproductive isolation that arises from variations in mating rituals or preferences, rather than physical separation. The notion of a state of being without organisms does not pertain to isolation in a biological context, and environmental changes typically refer to alterations in habitat conditions that might affect populations but do not specifically indicate the physical separation that defines geographical isolation. Thus, the understanding of geographical isolation focuses solely on the aspect of physical barriers impacting the reproductive capabilities of separated populations.