Are headlines about “three-parent babies” far-fetched, or spot-on? Today on The Gist, BuzzFeed science editor Virginia Hughes reminds us what we wish we remembered about mitochondrial DNA from ninth-grade biology. Plus, music writer Chris Molanphy explains why Tom Petty received credit for Sam Smith’s top-10 hit “Stay With Me.” For the Spiel, lower-upper middle-lower-upper class warfare.

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