by Jeff Wheelwright

About the author: Jeff Wheelwright’s books include The Irritable Heart: Gulf War Syndrome and the Limits of Modern Medicine (Norton, 2001). He is a former science editor of Life magazine and a freelance journalist.

Like a strand of DNA, which coils all over itself within a human cell, the biotechnology industry in San Diego is full of loops and tangles. Biotech, a big part of the “new economy” of the United States, is especially big in this seaside community, where the climate is said to be “technologies-perfect” and the race to put human genes to medical use has brought together large drug companies, shoestring start-ups, university labs and government hospitals.

If San Diego used to stand for bougainvillea, retired admirals and perpetual defense contracts, it now has a street named...