Deeper understanding of the plant and animal diversity on earth is perhaps the most important challenge faced by evolutionary biologists, ecologists, and conservation planners in the twenty-first century. In this study, modern DNA-based tools will be used to produce an evolutionary family tree of every species of turtle and tortoise on earth. Turtles are an ancient group, with living species that are well over 200 million years old, and many species that are hovering on the brink of extinction. This family tree, or phylogeny, will provide a detailed summary of the genetic distinctiveness of each of the approximately 313 species of living turtles, and how those species have diverged from each other over time. This project will provide the basic evolutionary information needed to rank turtle species for conservation prioritization. Given that over 50% of the world's turtle and tortoise species are in danger of extinction, such a ranking scheme is of critical importance to help guide conservation efforts. It will also help identify those features of species, such as large body size, breeding habitat, or longevity that contribute to their endangered status. By better understanding the relationship between evolved characteristics and level of endangerment, these results will help conservationists preserve turtle and tortoise species globally. Public education and student training in systematics and conservation biology are integral components of this research.