The images below show two types of finches that live on different Galapagos Islands. Scientists have found that these two finches are genetically related, but they eat different kinds of seeds. One species eats larger and harder seeds than the other species. What process caused these birds to have beaks with different shapes?

The correct answer is - natural selection or more precisely adaptive radiation.

Explanation:

Adaptive radiation is the process in the evolution of an animal or organism into different types of species or types specialized to fit different environmental conditions. These are depend on the various condition like food availablity or weather or any environemnt condition. It is the part of the natural selection that involves adapting the beneficial traits into genome of an organism over time period.

In galpago finches they are adapted different morphological condtions, based in food availblity in the particular environments even they had same ancestor is the best example of the adaptive radiation.