Final answer:
The study of herring gull behavior supports natural selection as researchers have found behaviors that protect and feed their young, leading to increased survival. Additionally, long-term studies of Galápagos finches have directly observed natural selection affecting beak sizes.
Step-by-step explanation:
The study of herring gull parental behavior provides support for evolution by natural selection because researchers found that certain traits and behaviors that increase the survival of offspring are favored. For example, herring gulls have a brightly colored bill which is used in various ways to increase the chances of survival for their young. In one case, when a predator approaches, the parent gull stands over its nest and taps the bill on the ground, signaling the information of the approaching predator to other gulls and prompting a protective response. In another context, the brightly colored bill of the parent gull elicits a begging response from their hungry chick when they tap it on the ground, which ensures that the chick is fed.
Similarly, Peter and Rosemary Grant and their colleagues have provided compelling evidence of natural selection through their long-term study of Galápagos finches, where they observed changes in beak sizes due to changes in seed availability.