A species of finch, from one of the geographically isolated Galapagos Islands, has been studied for many years by the scientists Peter and Rosemary Grant. Since the island is small, the scientists have been able to study several generations of the finches. The Grants observed that some family groups of finches have survived for many years and others have died out. The group that survived probably have _______.
interbred with other species
been attacked by more predators
found new places on the island to live
a reproductive advantage that makes them more fit for their environment