When Esvelt finally did publish his gene drive paper with several of his coworkers in eLife in 2014, they intentionally hadn’t executed it yet. They wanted to introduce the concept, consult with experts in various disciplines, and invite criticism; a majority of the paper is about safety, control, and ethical concerns. When they did make a drive for the first time in 2015, in yeast, they simultaneously built a second drive that overwrote the first and restored it. “Reversibility was one of the first things that we worried about,” Church said.In the spirit of harnessing CRISPR gene drive’s power, Esvelt and his colleagues have since developed another approach, dubbed a daisy drive. It is a gene drive designed to fizzle out. It won’t self-propagate forever, but uses a series of connected drives that eventually do succumb to natural selection. Esvelt has also been brainstorming ways to keep a drive from spreading by making it so that when an edited organism procreates with a non-edited one, it will create half as many offspring—a kind of genetic electric-dog fence.“It’s one thing for humanity to be able to do this. It’s quite another for individual researchers to have this kind of power.”
In 2015, at the University of California in San Diego, researchers were studying genes that create vein patterns in fruit fly wings. They figured out they could use CRISPR to make different mutant flies, and also make certain flies yellow, to tell them apart. It was a CRISPR-gene drive. They also recognized the changes could be inherited and self-propagate, and took safety and containment measures. But Esvelt was still concerned: If one of those flies had gotten out, it could have made a whole bunch of local fruit flies yellow. Not necessarily dangerous on its own, but what if a simple accident like this sparked a media frenzy, and turned the public against gene drive, halting ongoing malaria research?One accident could affect the whole future of this work. In 1999, a patient died while participating in a gene therapy trial at the University of Pennsylvania, which "really slowed down…the field for a decade at least," according to Kuzma. "Could it happen in the case of gene drive? Yeah," she said."The future of our civilization is primarily going to be determined by the technologies that we invent and the wisdom with which we choose whether, when, and how to use them."
He told me that he isn’t a fan of using consequentialism on a day-to-day basis, and it relieved me to know that Esvelt doesn’t apply his mortality calculations to everything. He doesn’t, for example, stand in the produce section of the grocery store counting up deaths when comparing organic to non-organic bananas. In everyday life, he turns to other philosophical role models, like Aristotle, and the Stoics Marcus Aurelius and Seneca. Aristotle’s view on ethics was that morality should be practical and not just relegated to theory. If a person wanted to be virtuous, they must do virtuous things, and not spend their time studying and pontificating about what virtue is. Esvelt said that in his life, he tries to combine that with a crucial insight from the Stoics, which is: If there’s nothing you can do about it, don’t stress.The thing is, though, the range of things that Esvelt can affect with his actions is a bit larger than, say, mine. I cannot personally change the DNA of a malaria-carrying mosquito, or a mouse carrying Lyme disease. Esvelt can. Can philosophical wisdom help him with the weight of that burden? Would Esvelt be happier if he didn’t need his envelope calculations, if he hadn’t come up with CRISPR gene drive, if he didn’t have to watch his words carefully, or think about the moral ramifications of every action?“I wouldn’t trade my job for the world,” he said, smiling. After a pause he continued, “I mean, I would. I would totally trade my job for the world. I would trade my life for the world. That’s sort of part of what comes with this, right?”Do scientists regularly calculate the consequences for their actions? Have they added up the number of lives, or the amount of suffering, they could cause or absolve? “You asked what frustrates me about the world. That’s what frustrates me, that people don’t think that way. They don’t connect morality to mathematics.”