No one needs to remind Jennifer Doudna about the power of CRISPR, the precision genome-editing technology she codeveloped. CRISPR “gives us a way to ultimately control the evolution of any organism—including ourselves. It is a profound thing. Human beings have now learned enough about our own genetic code that we can change it at will,” she said. “It’s kind of crazy to think about.”
That’s why when reports emerged last November that the scientist He Jiankui of the Southern University of Science and Technology in Shenzhen, China, had used CRISPR to alter the DNA of twin baby girls—crossing a line that genetic engineers had respected for decades and reaffirmed in 2015—Doudna was quick to speak out. Describing herself to the media as “horrified and stunned,” she criticized his actions as risky, premature and unnecessary, given the absence of pressing medical need for the children to be modified experimentally. She encouraged the international scientific community to develop better guidelines for permissible genome editing in humans.