If you were setting out to design a human being from scratch, odds are you wouldn't take J. Craig Venter as your template. You wouldn't choose to put him at risk for Alzheimer's disease, for example, but Venter has a predisposition that places him in danger of it. You might choose his startling blue eyes, both for their color and the hard clarity of their gaze. You'd surely go for his first-rate brain, though you might pass on what his detractors consider the vainglorious temperament that comes bundled with it.
It's something of an irony then that such an imperfect organism as Venter has devoted much of his career to understanding the engineering of other organisms. He was the leader of one of two teams that in 2000 sequenced the human genome—the entire 25,000-gene cookbook that makes us people in the first place and not chimps or birds or banana trees — and he has conducted the same work with many...
