Answer:
The correct answer is - natural selection or more precisely adaptive radiation.
Step-by-step 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.