Answer:
The beak size of Finches, Dark colour moth.
Step-by-step explanation:
The structural adaptation by Darwin is nothing but natural selection. By the process of natural selection, the organisms become more adjusted to their environment. The examples of Darwin's structural adaptation are the different beak sizes of Finches. The Finches developed different beaks to eat different insects and fruits instead of only seeds. Another example of structural adaptation is dark colour moth after England's industrial revolution. Before the industrial revolution, there was less pollution, and white-coloured moths were more. But due to increased pollution, black moth arise to escape from the predator. Other examples of structural adaptations are weight difference in polar beers, long necks of giraffes.