National Geographic : 2016 Aug
54 national geographic • August 2016 California, Berkeley, where she is professor of chemistry and molecular biology. In 2012, Doudna and her French colleague Emmanuelle Charpentier were the first to demonstrate that scientists could use CRISPR to edit purified DNA in lab dishes. “I don’t know that we know enough about the human genome, or maybe any other genome, to fully answer that question. But people will use the technology whether we know enough about it or not.” The more rapidly science propels humanity forward, the more frightening it seems. This has always been true. Do-it-yourself biology is already a reality; soon it will almost certainly be possible to experiment with a CRISPR kit in the same way that previous generations of garage-based tinkerers played with ham radios or rudimentary computers. It makes sense to be apprehensive about the prospect of amateurs using tools that can alter the fundamental ge- netics of plants and animals. But the benefits of these tools are also real, and so are the risks of ignoring them. Mosqui- toes cause immense agony throughout the world every year, and eradicating malaria or another says. “Avian malaria is destroying the wildlife of Hawaii, and there is a way to stop it. Are we really willing to just sit there and watch?” In February of this year, U.S. Director of National Intelligence James Clapper warned in his annual report to the Senate that tech- nologies like CRISPR ought to be regarded as possible weapons of mass destruction. Many scientists considered the comments unfounded, or at least a bit extreme. There are easier ways for terrorists to attack people than to conjure up new crop plagues or deadly viruses. Nevertheless, it would be shortsighted to pretend that the possibility for harm (includ- ing, and perhaps especially, accidental harm) does not exist with these new molecular tools. The scientists most responsible for advances like CRISPR agree that when we begin to tinker with the genetic heritage of other species, not to mention our own, it may not be easy, or even possible, to turn back. “ What are the unintended consequences of genome editing?” asked Jennifer Doudna, as we spoke in her office at the University of ALTERED GENE WILD ALTERED GENE WILD ALTERED GENE WILD EDITED SECTION CRISPR Most genes in a species have a one-in-two chance of being inherited by each offspring. But with the advent of CRISPR and a controversial technique called engineered gene drive, scientists are beating those odds in the lab. An alteration that makes a mosquito resistant to malaria, for example, can be engineered to be inherited by all its offspring. Spreading the Cure Natural process A gene is typically inherited by its offspring about 50 percent of the time.