Debugging The Planet

Even Editing Away Parasites Comes With Profound Ethical Quandaries.

- Michael Mechanic

NOT LONG AGO, Bill Gates noted on his blog that the deadliest creatures on the planet are not sharks or snakes or even humans but the lowly mosquitoes carrying a devil’s menagerie of diseases— malaria, dengue, chikungunya, yellow fever, Zika, West Nile—that kill hundreds of thousands of people each year.

But we may soon be able to end the mosquito’s reign of terror, thanks to a new technology known as gene drive, whose implications are at once thrilling and terrifying.

Suppose you were to engineer a genetic variation into an animal’s DNA. That anomaly would be passed along to half the creature’s offspring. Only a quarter of the subsequent generation would have the variation— and then an eighth and a sixteenth and so on. Gene drive—another spinoffof crispr—upends that calculus. Theoretically it would guarantee that a lab-modified trait can be inherited by all a creature’s offspring and all their offspring, until the whole population carries it.