David Houle is an evolutionary geneticist in the Department of Biological Sciences at Florida State University. He is currently studying the evolution of development and how it affects morphology. The biggest unknowns in biology are the paths through which genetic variation affects the phenotype, and in turn how the phenotype affects organismal fitness. He believes that we need to greatly increase our ability to measure phenotypic characteristics, the phenome, before we can understand this genotype-phenotype-fitness map. We use phenomic approaches in Drosophila melanogaster, the fruit fly, to get at these questions, using a combination of molecular, genetic, and whole-organism techniques. Our current projects characterize the variation produced by particular genes and developmental mechanisms, characterize the genetic variation in natural populations, and seek to explain how that variation can be used to produce evolutionary responses. He has undertaken a wide variety of other projects in the past, and is still interested in mutation, sexual selection, life history evolution, fluctuating asymmetry and measurement theory.