Perhaps you’ve heard of CRISPR — an enthralling bacteria-based gene-therapy technique that is spelled like a Silicon Valley joke, pronounced like the vegetable-drawer contraption in your aunt’s refrigerator, and promises, in fact, to so completely change the nature of our relationship to our own genes that Michael Specter’s recent account of it, in The New Yorker, was called “Humans 2.0.” They weren’t being all that hyperbolic: CRISPR is a way of dispatching a probe into a cell to seek out and modify a particular stretch of genetic code about a million times more efficiently, and much more cost-effectively, than has ever been possible before. It is often described as a genetic cut-and-paste tool: Using it, you can easily select any segment of DNA and replace or delete it. Which means that anything that’s genetic is editable, and since everything is genetic, at least partially, a whole lot of stuff might just be possible, from eradicating cystic fibrosis to (theoretically, anyway) gene-therapy sex changes. They’re already CRISPR-izing pigs to more easily grow human organs inside them for transplant. And, to fight malaria, unleashing an air force of reprogrammed mosquitoes.