Gene Drives

For many years now, scientists have been able to alter genes inside microbial, plant, and animal cells to change organisms’ traits, creating, for example, plants that produce their own protective insecticides and fish that grow to maturity almost twice as fast as normal. But while it has become practically routine for scientists to genetically alter individual organisms, a new set of advances promises something much more ambitious: the ability to propagate new genetic traits* into entire populations over just a few generations. Rapid, population-wide dissemination of new traits is challenging because in most sexually reproducing species, only half of an individual’s offspring will inherit any given version of a gene.

An emerging technology called a “gene drive” could solve this problem by overriding standard molecular mechanisms of inheritance and ensuring that virtually all offspring inherit a newly engineered trait, instead of just half. The prospect of accelerating the pace at which traits spread through a population from generation to generation is enticing. Imagine a few mosquitos, engineered so they can’t transmit malaria, passing that trait to every one of their many offspring until, over the course of just a few months, virtually no mosquitos in the area pose a risk of spreading malaria. But gene drives also present risks and ethical quandaries.…