Question

which is most likely to happen to a population that becomes anatomically isolated from the rest of its species?
the entire species will become extinct.
the population will become a separate species over time.
the population will breed with a different species nearby.
the entire species will continue to have viable offspring together.

Explanation:

When a population is anatomically isolated (a form of reproductive isolation), gene flow with the original species is restricted. Over time, due to different environmental pressures, genetic drift, and mutation accumulation in the isolated population, it can evolve independently. This can lead to the development of reproductive barriers (like anatomical incompatibilities for mating) that prevent interbreeding with the original population, fulfilling the biological species concept (a group of organisms that can interbreed and produce fertile offspring).

• The first option is wrong because only the isolated population is affected, not the whole species.
• The third option is incorrect as reproductive isolation (anatomical here) would prevent breeding with a different species (and even if attempted, offspring are often infertile like mules).
• The fourth option is wrong because the isolated population is cut off, so they won't breed with the original group to have viable offspring together.

Answer:

The population will become a separate species over time.