It was a quarter-century ago that Watson and Crick, playing with cardboard cutouts and wire-and-sheet-metal models and sorting out the few controlling facts from a hotchpotch of data, elucidated the molecular architecture of the genetic material itself, the double-railed circular staircase of deoxyribonucleic acid. What has been learned in the years since is full of surprises, full of wit and beauty, full of the most gratifying illumination. The culmination is now approaching of the great endeavor of biology that has swept on for a century and a quarter—an achievement of imagination that rivals the parallel, junior enterprise in physics that began with relativity and quantum mechanics. Biologists' pursuit of complete and explicit understanding has begun to list the exact molecular sequences that encode the hereditary message, instruction by instruction; it has tweezed apart the springs and gears by which the message is expressed in the building of the cell, and the ratchets and pawls by which that expression is regulated; it has accustomed men to speak apparently without wonder of the structural transformations by which a single protein molecule, an enzyme, will break or build other proteins, or by which, for example, a molecule of hemoglobin will flex its broad shoulders and bend its knees to pick up oxygen.
To be sure, the discoveries have not produced the great practical payout that has repeatedly been anticipated for them. Biologists have no atomic power stations and no bombs to point to, or at least not yet. No baby has been cured of a congenital deficiency by insertion of a missing gene into its cells. There is no vaccine against human leukemia, not even a cure for hay fever. Though some of the rewards are at last imminent, most scientists have learned that they must speak guardedly and emphasize to laymen the gaps to be filled in.
The Eighth Day of Creation, Horace Freeland Judson, 1979