Gary Ruvkun is a Professor of Genetics at Harvard Medical School. His lab uses C. elegans molecular genetics and genomics to study problems in developmental biology and physiology. Dr. Ruvkun is a graduate of UC Berkeley and Harvard. His PhD thesis with Fred Ausubel explored the symbiotic nitrogen fixation genes of Rhizobium. A hallmark of those genes is their conservation over 3 billion years of prokaryotic evolution. Dr. Ruvkun began to work with C. elegans as a postdoc with Bob Horvitz at MIT and Walter Gilbert at Harvard, where he explored the genes that control the temporal dimension of development. This work led to the discovery of the first microRNA genes, and the first detection of microRNA genes in other animals, and the discovery of a relationship with RNAi, now an exploding field. Over the past few years, Dr. Ruvkun’s lab has discovered that, like mammals, C. elegans uses an insulin signaling pathway to control its metabolism and longevity. This analysis has revealed striking congruence of molecular mechanisms at many steps in the pathway, and most importantly, new components also likely to be ancient and universal. These discoveries have implications for treatment of diabetes, a disease of insulin signaling. Using RNAi libraries of nearly every C. elegans gene, Dr. Ruvkun’s lab has surveyed 17,000 genes for their action in regulation of longevity, fat deposition, and RNAi. This analysis gives a global view of the molecular machines that operate in these pathways. Dr. Ruvkun has also analysed the complete C. elegans genome sequence for conserved microRNA and mRNA coding genes. The genome sequence reveals universals in developmental control that are the legacy of metazoan complexity before the Cambrian explosion as well as probable developmental control genes that have been more recently invented or lost in particular phylogenic lineages. The scientific value of the cartography of these genes is in the power to explain universal features of animal development as well as features that are particular to invertebrates or nematodes.