Marsupials, such as kangaroos, koalas, and wombats, are mammals that care for their newborn young in a pouch. all marsupials that are found in australia are thought to have evolved from a single species that migrated to the island and then adapted to the various niches. what does this example illustrate?
behavioral adaptation
adaptive radiation
geographic isolation
population explosion

This example illustrates adaptive radiation

Adaptive radiation is a process in which closely related organisms that evolves from an ancestral species become more diverse, and separate to form new groups that are adapted to various niches with specialized modes of life. Adaptive radiation occurs as a result of changes in the environment and may create many new niches, new resources, or new problems.

the correct answer is 2 and 4