The picture shows the finches that Darwin observed on the Galapagos Islands in 1835.
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Why do these finches have different beaks?
A.
The finches were artificially selected to acquire different genetic traits.
B.
The finches' beaks changed shape as they grew from adolescents into adults.
C.
The finches mated with other species of birds, producing offspring over generations with the most desirable traits from each species.
D.
Environmental changes altered the available food sources, allowing the finches with suitable beaks to survive and reproduce.