How does genetic isolation lead to divergence and speciation?

Genetic isolation leads to divergence and speciation by preventing gene flow between populations, leading to distinct genetic variations.

Genetic isolation is a key mechanism in the process of speciation, the formation of new and distinct species in the course of evolution. It occurs when a population of organisms is separated from exchanging genetic material with other organisms of the same species. This can happen due to various reasons such as geographical barriers, behavioural changes, or reproductive isolation.

When populations are isolated, they are exposed to different environmental conditions and selective pressures. Over time, these different conditions can lead to the development of unique adaptations and traits in each population. This is known as divergence. Divergence can occur in many ways, such as through genetic drift, where random changes in gene frequencies can lead to significant differences over time, or through natural selection, where certain traits become more common in a population because they provide a survival or reproductive advantage.

As divergence continues, the genetic differences between the isolated populations can become so great that individuals from the different populations can no longer interbreed to produce fertile offspring. This is the point at which speciation has occurred. The populations have become so genetically distinct that they are now considered separate species.

In summary, genetic isolation acts as a barrier to gene flow, allowing populations to diverge genetically under the influence of genetic drift and natural selection. Over time, this divergence can lead to the formation of new species, a process known as speciation. This is a fundamental concept in evolutionary biology and is key to understanding the diversity of life on Earth.