A long history of analysis has taken apart organisms into molecular structures. However, the understanding of how biological forms are put together in development and evolution has eluded biologists until very recently. Comparative molecular data on genes in different phyla is uncovering an extraordinary conservation since Precambrian times of gene structures associated with functions. The implications of these findings and our increasing knowledge of how genes control development in a few model organisms, invites a consideration of possible approaches to tackle the problem of how organismic forms are constructed and evolve.