Input (grade 13): His identification of the birds now nicknamed "Darwin's finches" was pivotal in the inception of Darwin's theory of evolution by natural selection, though they are barely mentioned in Charles Darwin's book, On the Origin of Species.
Output (grade 8): His knowledge of the birds now called "Darwin's finches" was a turning point in the Charles Darwin's thinking about evolution by natural selection. They are barely mentioned in Charles Darwin's book, On the Origin of Species.