Beyond gene-edited babies: the possible paths for tinkering with human evolution

In 2016, I attended a large meeting of journalists in Washington, DC. The keynote speaker was Jennifer Doudna, who just a few years before had co-invented CRISPR, a revolutionary method of changing genes that was sweeping across biology labs because it was so easy to use. With its discovery, Doudna explained, humanity had achieved the ability to change its own fundamental molecular nature. And that capability came with both possibility and danger. One of her biggest fears, she said, was “waking...