Two populations of mice live in the same forest. After a rainstorm, flooding causes a new river to form, which completely separates the populations. When the mice reproduce, which of the following will likely occur? *
A. All the offspring will die as a result of reproductive mutations.
B. The offspring will be forced to leave the second population.
C. The offspring will be genetically identical to the original, unseparated population.
D. The offspring in the new populations will have less genetic variety due to smaller populations with different gene pools.