You searched for: “geographic speciation
geographic speciation (s), geographic speciations (pl) (nouns)
The evolutionary development of plant or animal groups whose members all have similar general features and are able to produce young plants or animals together: "An evolutionary change leading to the rise of new species resulting from the separations of biological populations into mutually exclusive geographic regions, thereby creating distinct gene pools."

"Differentiation of populations of biological groups in various geographical isolations to the point where they are recognized as separate species."