Adam Rutherford is a geneticist and author who just wrote a new book about the history of eugenics, and he tells NPR's Rebecca Ramirez that the political ideology is not just a relic of the past, but very much still relevant today. In this episode, Rutherford explains how anti-immigrant fear in the 19th century spurred popularity for an unscientific practice that was eventually embraced by Nazis – and has a complicated relationship with today's reproductive rights movement.