Studies of conserved biological processes require model organisms that share attributes with humans. Most model organisms are easily grown in the laboratory and enable experimental manipulations. Over the last forty years, the nematode worm Caenorhabditis elegans has been instrumental in numerous fundamental advances in genetics, developmental biology, and neurobiology. However, all of these discoveries come from studies of a single genetic strain of the species. This limitation is similar to the argument that we can understand all of human biology by the study of a single person in our species. This project seeks to expand the C. elegans Natural Diversity Resource (CeNDR), which includes nearly 2,000 genetically distinct strains from across the world, and create the Caenorhabditis Natural Diversity Resource (CaeNDR), incorporating almost 2,000 C. briggsae and more than 700 C. tropicalis strains. This combined genetic diversity facilitates discoveries about the evolution of physiological and behavioral traits, including responses to chemical and biotic stresses. Because humans share many of the same genes and processes as this nematode species, studies using these organisms can teach us a great deal about how the human population varies and how evolution works.<br/><br/>CaeNDR has three major goals: (1) Collect, organize, and disseminate wild Caenorhabditis strains; (2) Organize and disseminate whole-genome sequence and variant data for wild strains; and (3) Provide a genetics portal to facilitate mappings and interpretations of results. The project will further increase the capacity of CaeNDR by expanding the set of strains and preparing them for easy dissemination to the community, adding new tools and extensibility to existing CaeNDR genomic resources, and releasing all of the data for the three Caenorhabditis species on an updated and redesigned website (CaeNDR.org) with critical improvements to security, infrastructure costs, and user interface and experience. The extensive CaeNDR user-base from C. elegans will be amplified by researchers using C. briggsae and C. tropicalis, allowing for novel comparative approaches across the Caenorhabditis genus. Most research groups do not have the combination of experimental, computational, and statistical training to easily perform studies of natural variation. This project will make these tools available and usable by a large number of research laboratories across diverse model organism communities.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.