A group of mice becomes separated by the formation of a river. Over time, the northern mice become smaller and whiter, while the southern mice became larger and browner. This is an example of
Homology
Gigantification
Divergence
Industrial melanism
Divergence
The correct answer is divergence.
Divergence refers to the process by which populations of the same species become increasingly different from each other over time. In the given example, the northern mice and southern mice have diverged in terms of their size and coloration due to the geographical barrier of the river. The selection pressures and unique environmental conditions in the separate regions have led to the divergence in physical traits of the two populations.