The old man and the sea urchin genome: theory and data in the work of Eric Davidson, 1969-2006.  Eric Davidson''s work from 1969-2006 illustrates a period in the study of gene regulation that marked a transition from the gene to the genome and from theory-driven to data-intensive science. To make sense of this transition, I address Davidson''s work during a first, predominantly theoretical, episode and contrast it with a later chapter in his research devoted to sequencing the California purple sea urchin genome and, more recently, to the computerized analysis of sea urchin development. By comparing these two approaches I offer some thoughts on how work configuration and material organization in the study of metazoan gene regulation have changed over the past forty years.