Geographic isolation is when a continuous population is divided into two or more smaller populations because of change in geography or migration. For example, this deer population is about to be affected by geographic isolation.
Their habitat has received an abnormal amount of rainfall in a small amount of time. This heavy rainfall has caused a flood. Which will divide the population.
The large population of deer have been separated by a river that was made by heavy rainfall and flooding.
What was once a continuous large population of deer is now two smaller species of deer.
There is now a dark colored fur deer that blends in better to the darker parts of the forest.
There is also a lighter colored species of deer that lives in the more open part of the forest.