As the above photos attest, Homo sapiens is not a perfect species. Gene therapy could change that.

Altering the code of those with a specific illness embedded in the “alphabet” of who they are is an area of great promise. But what if those changes to DNA could be made hereditary? What if we “optimize” humans across generations to not only be rid of disease but to increase intelligence and strength and to weed out characteristics that are considered unfavorable at this moment in history? Will we make things worse while trying to make them better? It’s a pretty sure bet that if we don’t destroy ourselves in the short run with greenhouse gases or by some other means, we’ll have to work through these questions. The opening of “Engineering the Perfect Baby,” Antonio Regalado’s Technology Review inquiry into the future of parenting:

If anyone had devised a way to create a genetically engineered baby, I figured George Church would know about it.

At his labyrinthine laboratory on the Harvard Medical School campus, you can find researchers giving E. Coli a novel genetic code never seen in nature. Around another bend, others are carrying out a plan to use DNA engineering to resurrect the woolly mammoth. His lab, Church likes to say, is the center of a new technological genesis—one in which man rebuilds creation to suit himself.

When I visited the lab last June, Church proposed that I speak to a young postdoctoral scientist named Luhan Yang, a Harvard recruit from Beijing who’d been a key player in developing a new, powerful technology for editing DNA called CRISPR-Cas9. With Church, Yang had founded a small company to engineer the genomes of pigs and cattle, sliding in beneficial genes and editing away bad ones.

As I listened to Yang, I waited for a chance to ask my real questions: Can any of this be done to human beings? Can we improve the human gene pool? The position of much of mainstream science has been that such meddling would be unsafe, irresponsible, and even impossible. But Yang didn’t hesitate. Yes, of course, she said. In fact, the Harvard laboratory had a project to determine how it could be achieved. She flipped open her laptop to a PowerPoint slide titled “Germline Editing Meeting.”

Here it was: a technical proposal to alter human heredity.

“Germ line” is biologists’ jargon for the egg and sperm, which combine to form an embryo. By editing the DNA of these cells or the embryo itself, it could be possible to eliminate disease genes and to pass those genetic fixes on to future generations. Such a technology could be used to rid families of scourges like cystic fibrosis. It might also be possible to install genes that offer lifelong protection against infection, Alzheimer’s, and, Yang told me, maybe the effects of aging. These would be history-making medical advances that could be as important to this century as vaccines were to the last.

That’s the promise. The fear is that germ line engineering is a path toward a dystopia of super people and designer babies for those who can afford it.•