From the gene to behavior.

The problem of gene structure and coding was exciting while it lasted. The story of the past two eventful decades, including my own contributions, has been well told, 1-3 and need not be repeated here. But molecular genetics, pursued to ever lower levels of organization, inevitably does away with itself: the gap between genetics and biochemistry disappears. More recently, a number of molecular biologists have turned their sights in the opposite direction, ie, up to higher integrative levels, to explore the relatively distant horizons of development, the nervous system, and behavior. When the individual develops from an egg, the one-dimensional information contained in the linear sequence of genes on the chromosomes is somehow translated into a two-dimensional blastula, which later folds to produce a precise three-dimensional array of sense organs, central nervous system, and muscles. Finally, the ensemble interacts to produce behavior, a phenomenon which requires four dimensions, at the