The beaks are different depending on the food available on the island.
Answer: if change happens naturally in an ecosystem it will be better evolved to handle it. But at the expense it happens very slowly
Explanation: my answer
Survival of the fittest is talking about when you have traits that will help you, you are more likely to live rather than not having those traits. For example, a bird that swims a lot has webbed feet so it has a better chance of surviving then a bird who does not have webbed feet
