This is an exciting time in Developmental Biology. Although for over 100 years developmental biologists have tried to unravel the mystery of embryogenesis, much of what we now know about the molecular basis of development has been learned in the last decade. Surprisingly, this avalanche of knowledge has simplified rather than complicated our understanding of this question. We now know that developmental genetic pathways have been remarkably well conserved in evolution. For example, genetic studies of fly embryogenesis revealed the Hedgehog protein, a secreted signaling molecule that has been shown to pattern the vertebrate brain as well. Thus, it is clear that studies of simple model organisms can uncover developmental mechanisms of fundamental importance to humans. This powerful paradigm is the touchstone of the Vanderbilt Program in Developmental Biology -- scientists studying diverse model organisms working together to unravel key developmental processes.