On the island of Daphne Major in the Galapagos, there are many different species of finches. In general, large ground finches with large, deep beaks would eat large, spiny seeds found on the ground. Small and medium sized finches with shorter beaks usually ate nuts, berries, and small tender seeds. In 1976 the island suffered an 18 month drought which forced the medium-sized ground
finches to compete with the large finches for the large, spiny seeds found on the ground. The graph below shows the distribution of beak depths of the finch population before the drought (white bars)
and after the drought (black bars).
Based on evidence from the graph, which of the following best explains how the population of the finches changed after the drought of 1976?
50
1976 Parents
40-
30
IL
1...
20-
10-
73
103
108 113
1883 88 93 9.8
A
Beak Depth (mm)