Example of Geographic Isolation

Geographic isolation is an expression related to a scientific principle in which a location is physically separated from other places by a barrier like a mountain range or an ocean. This principle is common when defining issues of evolutionary development, like Darwin's theories regarding the Galapagos island ecology. Historic geographic isolation relates to insularity within societies and cultures.

Examples of Geographic Isolation:

Australia's unique ecology and wildlife.
Japanese culture prior to confrontation with the West.
Islands are said to be geographically isolated by definition, with some groups containing quite different ecologies even within themselves.
Coral reef ecosystems, particularly major systems, can be separate structures, isolated like continents.
https://en.wikipedia.org/wiki/Geographical_isolation

Image Example of Geographic Isolation:

The geographic isolation of australia created a sharp division between australian fauna and asian fauna at the wallace line.