TR: What kinds of traits will it be possible to engineer? Are parents going to be able to pick the height, intelligence, or musical talents of their children?Stock: Right now we don’t know what’s going to be too complicated to do and what will be very, very easy. I think we’ll be surprised at the numbers of things that turn out to be easy. Certainly, there have already been complex traits-ones undoubtedly shaped by many genes-that can be substantively altered by changing one gene. Researchers have modified single genes to roughly double the life span of fruit flies and roundworms. And there was recently an astonishing study where researchers changed one gene in mice, and it greatly enlarged their brains and gave them a wrinkled, deeply folded surface similar to that of the human brain instead of the smoothness typical of a mouse. When medical science begins to understand our genetics, it will become possible to screen for various constellations of genes that will likely bring beneficial effects-tendencies towards vitality and health or various personalities and predispositions we like. And once we start using such information to choose embryos, it won’t take us long to start thinking seriously about just going in and creating those sorts of genetic constellations directly.
TR: You speak of “our inevitable genetic future.” Won’t numerous groups want to limit if not outright ban such technology?
Stock: No matter how much we discuss these things, we’re not going to reach a consensus about what should be done. These issues touch our values too deeply, hinging on culture, religion, and philosophy. Those who want to stop such technology do not want to do so because they think it may go awry and cause injuries, although that’s what they say. They want to stop it because they fear it will be wildly successful and sweep humanity toward a pernicious future. And they feel an urgency to stop such technology now, before it even arrives, because they’re afraid that if we get too much benefit from it, then too many people will see it as desirable. For example, you would be hard put to ban in vitro fertilization now: too many children are here because of the technology; too many happy parents would be childless without it. And it could be the same with many of these other technologies.
I don’t believe it will be possible to stop germline intervention. But the politics will have impacts on where breakthroughs are made. A good example is therapeutic cloning-the work on embryonic stem cells to treat Alzheimer’s, diabetes, and other diseases. Even though the 2002 attempt to ban this in the United States failed, the associated uncertainty has made this country a very problematic environment for doing this sort of work. So a number of researchers have moved overseas: there are strong efforts in Britain, Singapore, and Australia. The U.S. government could not halt these technologies, even if it wanted to. We can make a lot of noise about particular clinical applications, but ultimately we should remember that this will happen because these potentials are really just spinoffs of mainstream medical research that we all want.