Natural selection can lead to the creation of new species through the process of speciation. One example of how this can happen is through allopatric speciation, which occurs when a population is divided by a geographical barrier. Here's a step-by-step explanation:
1. Initially, a single population of a species exists in a continuous area.
2. Due to geological events like the formation of a mountain range, a river changing course, or the formation of a new island, the population gets separated into two isolated groups.
3. The two separated populations are now subjected to different environmental conditions, leading to variations in their gene pools due to factors like different food sources, predators, climate, etc.
4. Over time, these variations accumulate through natural selection, genetic drift, and mutations, causing the two populations to diverge genetically.
5. Eventually, if the genetic differences between the two populations become significant enough, they may no longer be able to interbreed successfully if they come into contact again.
6. At this point, they are considered distinct species that have evolved through the process of natural selection in response to their respective environments.
This example illustrates how natural selection, acting on populations that are geographically isolated, can drive the formation of new species over time.
