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While the world frets over whether CRISPR, a powerful genetic engineering technique, should be used to alter the DNA of our children, a pair of researchers in San Diego achieved something more sweeping and, according to some scientists, equally disconcerting.

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paper published yesterday , Valentino Gantz and Ethan Bier, both at the University of California, San Diego, demonstrated the first successful implementation of a CRISPR-Cas9-based gene drive in the germ line of fruit flies. The CRISPR gene drive is a powerful piece of technology that all but guarantees an engineered trait is passed on to every single offspring. Within months or years, it has the ability to alter an entire population of a sexually reproducing species.

It’s no coincidence that a slew of scientists

published a commentary yesterday in the journal Science urging caution in editing both human and non-human germ lines, or the eggs and sperm that pass traits from one generation to the next. The commentary has already received a fair amount of attention, but much of the media has focused on the human side of the story, envisioning a world where privileged offspring are granted superior genetic qualities. Their concern isn’t misplaced—many scientists also express the need for a discussion around so-called designer babies.

But such intense anthropocentrism risks overlooking the fact that gene drives can be used to modify entire nonhuman populations, too. In fact, Gantz and Bier have already done exactly that, and it’s likely that the first non-laboratory use of a CRISPR gene drive will be in a wild species, not a human being.

Last summer, I wrote about the efforts of Kevin Esvelt and George Church, both at Harvard’s Wyss Institute, and Kenneth Oye of MIT to spark a conversation about the use of CRISPR gene drives in human and nonhuman species. They had hoped that an open debate would institute a series of guidelines and rules for labs around the world to follow…before the work got started.

The risk of Gantz and Bier’s fruit flies escaping their lab at UCSD is minimal—the facility is apparently layered with security measures, according to John Bohannon at Science . But the larger community’s concern is that other labs—maybe in the U.S., perhaps not—won’t be as careful. Modified critters could easily escape, or carefully designed species released into the wild could have unintended consequences, sparking a cascade of ecological changes that may be all but impossible to reverse. It’s because of these possibilities that the CRISPR community wants everyone to weigh in.

Though yesterday’s commentary strikes a cautionary tone, neither do its authors want to see CRISPR gene drives disappear. The technology has the potential to sweepingly alter the world for the better—wiping out malaria, fostering the development of benign pesticides, even bringing species back from extinction. Which is why the conversation about the technology’s use is so urgently needed. In less than six months, CRISPR gene drives went from published theory to practical application. Who knows what will happen six months from now?