The work of Thomas R. Cech has revolutionized the way in which scientists look at RNA and at proteins. Up to the time of Cech's discoveries in 1981 and 1982, it had been thought that genetic coding, stored in the DNA of the nucleus, was imprinted or transcribed onto RNA molecules. These RNA molecules, it was believed, helped transfer the coding onto proteins produced in the ribosomes. The DNA/RNA nexus was thus the information center of the cell, while protein molecules in the form of enzymes were the workhorses, catalyzing the thousands of vital chemical reactions that occur in the cell. Conventional wisdom held that the two functions were separate--that there was a delicate division of labor. Cech and his colleagues at the University of Colorado established, however, that this picture of how RNA functions was incorrect; they proved that in the absence of other enzymes RNA acts as...