As the gene editing field kept growing, so did the dangers. Back in 2018, Jennifer Doudna received an email from a Chinese scientist claiming that he had genetically edited two twin babies. The news reverberated across the world and made Doudna and her colleagues urgently consider the implications of what their discovery could mean for humanity. 

Walter Isaacson sits down with Evan and tells him why the field has always been ripe with ethical questions, and how the COVID-19 pandemic pushed researchers to recalibrate their priorities.