>>58007579
Finally, divergence occurs when individuals from a close common ancestor change significantly from one another due to the different environmental stresses to which they are exposed. Using the previous example, lions and tigers have a common ancestor, but one adapts to the savannah and group life, while the other adapts to the jungles and snowy forests, leading a more solitary life.

In Pokémon, you have Meowth and its different regional forms; Eevee would be a more extreme case of adaptability.