A central goal of research in the Chakraborty lab is understanding the genomic and molecular basis of phenotypic variation and adaptation. While most changes in a trait affecting organismal fitness are considered deleterious, many are adaptive. Our lab is interested in understanding the molecular properties, functional effects, and evolutionary dynamics of the mutations that cause variation in complex traits (i.e., traits with complex genetic basis). Our present focus is on mutations caused by large (>100 bp) changes in genome structure (e.g., duplication, deletion, transposition, inversion of sequences), collectively known as structural variants or SVs. Although SVs cause diseases and drive adaptations, short reads miss many genome-wide SVs, obscuring candidate mutations for phenotypic variation and adaptation. We employ cutting-edge methods in genomics, genome editing, and population and quantitative genetics to decipher the functional and evolutionary consequences of SVs at the molecular, cellular, and organismal levels. We use the model organism Drosophila melanogaster and the invasive malaria vector Anopheles stephensi) for our research, but we are extending our work to other organisms.