Recent molecular biology has seen the development of genomics as a successor to traditional genetics. This paper offers an overview of the structure, epistemology, and (very briefly) history of contemporary genomics. A particular focus is on the question to what extent the genome contains, or is composed of anything that corresponds to traditional conceptions of genes. It is concluded that the only interpretation of genes that has much contemporary scientific relevance is what is described as the “developmental defect” gene concept. However, developmental defect genes typically only correspond to general areas of the genome and not to precise chemical structures (nucleotide sequences). The parts of the genome to be identified for an account of the processes of normal development are highly diverse, little correlated with traditional genes, and act in ways that are highly dependent on the cellular and higher level environment. Despite its historical development out of genetics, genomics represents a radically different kind of scientific project.