Bill McKibben

About the author: Bill McKibben is a former staff writer for the New Yorker and author of several books, including The End of Nature, Maybe One, and Enough: Staying Human in an Engineered Age, from which the following excerpt is taken.

The rate at which gene therapy is advancing reveals that it may be possible to manipulate the human germ line (egg or sperm cells) to make future generations smarter, taller, and maybe even happier. Although this is an attractive picture, it does not mean that parents should be given the choice to mentally, physically, or emotionally enhance their children through germ line gene therapy. Allowing so would exacerbate, not aid, the pursuit for a better child because genetic enhancements would inevitably become obsolete as genetic...