Task: Question Answering
Input (English): Background Paragraph: While the Grants were on the Galápagos, a drought occurred. As a result, fewer seeds were available for finches to eat. Birds with smaller beaks could crack open and eat only the smaller seeds. Birds with bigger beaks could crack and eat seeds of all sizes. As a result, many of the small-beaked birds died in the drought. Birds with bigger beaks survived and reproduced (see Figure below ). Within 2 years, the average beak size in the finch population increased. Evolution by natural selection had occurred. 
Story: Two neighboring islands inhabited by thousands of birds each were hit by extreme weather. While Port island experienced wet weather over the past 3 summers, Bank island experienced severe drought, therefore the food supply on the island diminished. 
Question: Which island had observed the occurrence of natural selection?
Output (English): Bank.