How does allopatric speciation occur?

Allopatric speciation is a process in which new species evolve from a single ancestral species due to geographic isolation. This type of speciation occurs when a population is divided by a physical barrier, such as a river, mountain range, or ocean, leading to the isolation of different groups of organisms.

Geographic isolation

The isolation of populations prevents gene flow between them, which is crucial for the formation of new species. Over time, the separated populations undergo independent evolutionary changes, such as genetic mutations and natural selection, in response to their unique environments.

Distinct populations

As the isolated populations continue to evolve independently, they may accumulate genetic differences that lead to the development of distinct traits. These traits can eventually become fixed in each population, further distinguishing them from one another.

Evolution

Through the process of evolution, the isolated populations may become reproductively isolated, meaning they can no longer interbreed and produce viable offspring. This reproductive isolation is a key factor in the formation of new species and is a defining characteristic of allopatric speciation.

In conclusion, allopatric speciation occurs through geographic isolation, which leads to the evolution of distinct populations and ultimately the formation of new species through reproductive isolation.