Rewriting Life
Gene Drives That Tinker with Evolution Are an Unknown Risk, Researchers Say
Too little is known about the risks of gene drives to responsibly release them in natural environments, say the authors of a new National Academies report.
With great power—in this case, a technology that can alter the rules of evolution—comes great responsibility. And since there are “considerable gaps in knowledge” about the possible consequences of releasing this technology, called a gene drive, into natural environments, it is not yet responsible to do so. That’s the major conclusion of a report published today by the National Academies of Science, Engineering, and Medicine.
Gene drives hold immense promise for controlling or eradicating vector-borne diseases like Zika virus and malaria, or in managing agricultural pests or invasive species. But the 200-page report, written by a committee of 16 experts, highlights how ill-equipped we are to assess the environmental and ecological risks of using gene drives. And it provides a glimpse at the challenges they will create for policymakers.
The technology is inspired by natural phenomena through which particular “selfish” genes are passed to offspring at higher rate than is normally allowed by nature in sexually reproducing organisms. There are multiple ways to make gene drives in the lab, but scientists are now using the gene-editing tool known as CRISPR to very rapidly and effectively do the trick. Evidence in mosquitoes, fruit flies, and yeast suggests that this could be used to spread a gene through nearly 100 percent of a population.
The possible ecological effects, intended or not, are far from clear, though. How long will gene drives persist in the environment? What is the chance that an engineered organism could pass the gene drive to an unintended recipient? How might these things affect the whole ecosystem? How much does all this vary depending on the particular organism and ecosystem?
Research on the molecular biology of gene drives has outpaced ecological research on how genes move through populations and between species, the report says, making it impossible to adequately answer these and other thorny questions. Substantially more laboratory research and confined field testing is needed to better grasp the risks.
The authors of the report call on researchers to use extreme caution to prevent gene-drive modified organisms from being accidentally released into the wild. They also warn that the technology will challenge governments, which haven’t developed laws that are adequate to deal with gene drives.
Kevin Esvelt, a biologist and professor at the MIT Media Lab, says that although the report gets a lot right, it should have gone further in its recommendations. Since it’s possible for a single organism to spread a gene drive throughout an entire species, “a release anywhere may well be equivalent to a release everywhere,” he says. That means anyone planning to make a gene drive should be obligated to make those plans public before performing experiments.
