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An excellent hour of radio from Radiolab.   Several stories around the theme of unintended consequences.   From the episode description:

You come up with a great idea. You devise a plan. You control for every imaginable variable. And once everything’s in place, the train hops your carefully laid tracks. In this episode, one psychologist's zeal to safeguard national security may have created a terrorist, while one community's efforts to protect an endangered bird had deadly consequences. And against all odds, a toxic lake spawns new life.

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