A most remarkable event occurred in the weeks preceding the June 2000 announcement of the completion of the first draft of the human genome DNA code: One of the leaders of the genome project publicly called for strict limits on what the scientific community should be permitted to do with the human genetic blueprint now in hand.

At a conference at MIT, Dr. Eric Lander, leader of the team that decoded the largest portion of the genome, called the conference to attention with this surprisingly stark suggestion:

Already, there are well-meaning discussions about improving the human DNA. I find this somewhat hubristic myself. [The human genome] has been 3.5 billion years in the making. We've been able to read it for the last, oh, I don't know, year or so. And we suddenly think we could write the story better? It's very amusing.

There is the prospect that by changing things we might put off aging, prevent cancer, improve memory. I find it a very difficult question. For my own part, I would put an absolute ban in place on...