Lincoln. Darwin's work was a lot more far-reaching, but it is also a lot more easily manipulated to support some truly evil causes. See Hitler's Germany.
That's a gross oversimplification. Nazi Germany would likely have still come about in a similar form even without evolutionary theory being available. Hitler also used religion to manipulate people, and it's not like using Jews as a scapegoat for social ills was a new phenomenon in Europe.
Also, you can't blame the manipulation of legitimate science to fit into some twisted ideology on the scientists when they aren't the ones manipulating it.
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