In simple terms, evolution represents changes in the hereditary traits of populations over time. In truth, the idea is quite simple. Life on Earth has evolved gradually over more than 3.9 billion years.

As time passed, species underwent genetic changes, passing beneficial traits on to their descendants and branching off into new and diverse species. After many generations, species can evolve into something quite different from the original. Given enough time, this cumulative process has far-reaching consequences.

Natural selection is one of the principal mechanisms responsible for evolutionary change, although it is not the only one. Natural selection is possible because there will always be individuals better suited for the environment in which they live.

These individuals leave more descendants than others. It is said that the individuals who survive are selected naturally; they do not do so randomly. They survive because they have specific traits that offer them a reproductive advantage.

But let’s not get ahead of ourselves. Let’s examine in detail each of the processes that drive evolution.