In this century, the study of the molecules of life has transformed the practice of biology as a whole. Molecular thinking now influences the research agenda for scientists studying both the behavior of individual cells and organisms, and the relationships between organisms as in natural history. Even ecology and anthropology are being influenced by this molecular revolution. It is impressive that this transformation has, to a large extent, been made possible by simply identifying (with very clever strategies!) active biological molecules and cataloging their information content through their sequences. One result of all this activity is that raw data about life at the molecular level have become abundant, but understanding its biological meaning remains, in many if not most respects, perplexing. Fortunately, just at this stage, new approaches to understanding the connection between biomolecular sequence and physiological behavior are coming forward. Computation, theory, and novel experimental approaches that utilize the combinatorial power of the genetic code allow us to begin to understand biomolecular function from both the bottom-up atomistic point-of-view of the physical sciences and the top-down view usually associated with the evolutionary perspective. The …