One of the biggest and most important science stories of the last few years will probably also be one of the biggest science stories of the next few years. So this is as good a time as any to get acquainted with the powerful new gene-editing technology known as CRISPR.

If you haven’t heard of CRISPR yet, the short explanation goes like this: In the past five years, scientists have figured out how to exploit a quirk in the immune systems of bacteria to edit genes in other organisms — plant genes, mouse genes, even human genes. With CRISPR, they can now make these edits quickly and cheaply, in days rather than weeks or months. (The technology is often known as CRISPR/Cas9, but we’ll stick with CRISPR, pronounced “crisper.”)

Let that sink in. We’re talking about a powerful new tool to control what genes get expressed in plants, animals, and even humans. The ability to delete undesirable traits and, potentially, add desirable traits with more precision than ever before.

In 2017 alone, researchers reported in Nature that they’d successfully used CRISPR in human embryos to fix a mutation that causes a terrible heart muscle disorder called hypertrophic cardiomyopathy. (Other researchers have since called some of the conclusions into […]