The birds shown below live on a single island.

Question

These four bird species are closely related, and all of them share a common ancestor with a single species. What environmental factor is most likely to have caused this diversity of species?

A. When the ancestral species arrived at the island, there was only one food source, so the ancestral species left the island immediately.
B. When the ancestral species arrived at the island, there was only one food source available and no need for different beak shapes.
C. When the ancestral species arrived at the island, there were multiple food sources available, and different beak shapes evolved for the most efficient eating.
D. When the ancestral species arrived at the island, there were multiple food sources available, and the different beak shapes were equally efficient for eating different food sources.

Answer 1

The option that best explains the diversity of bird species is:

C. When the ancestral species arrived at the island, there were multiple food sources available, and different beak shapes evolved for the most efficient eating.

This choice outlines a scenario in which adaptive radiation occurs, as the different beak shapes would allow various species to exploit different niches and food sources effectively. This diversity in beak shapes would have been driven by natural selection, leading to the evolution of multiple species from a common ancestor.