Geographic barriers play an important role in the formation of new species. This process is called speciation. Let’s break down how geographic barriers work:

1. What Are Geographic Barriers?
   Geographic barriers are physical things like mountains, rivers, or oceans that keep groups of living things apart.

2. Separation
   When a group of animals or plants is split by these barriers, they can’t mix their genes. This means that the two groups cannot share genes anymore. This separation can cause them to follow different paths in how they evolve over time.

3. An Example
   Think about the Galápagos finches. These birds have changed into different species because they adapted to the different environments on separate islands.

4. Adapting
   Each group that is isolated starts to get used to the specific conditions of its environment. This process happens over time and leads to differences in their genetic makeup.

5. The Outcome
   In the end, these genetic changes can become so big that even if the two groups come back together, they can’t reproduce with each other. This means they become distinct, or separate, species.