Since Darwin's time, there has been much debate about the predictability of evolution; what really will happen if we replay the so-called "tape of life"? From one perspective, evolution may be dictated by contingencies with unpredictable trajectories at the outset of any diversification event. Alternatively, evolution may be more deterministic with diversification of species filling similar ecological roles. Remote oceanic archipelagos, with their discrete and often replicated islands, provide model systems to study these replayed evolutionary trajectories. My work will study a lineage of Tetragnatha spiders in the Bonin Islands of Japan where the endemic species appears to mirror morphologically and ecologically, a known adaptive radiation of Tetragnatha spiders in the Hawaiian Archipelago. This comparison across the two islands will enable us to test the repeatability of evolution in two entirely independent, but related lineages evolving under similar environments. Listed as a World Heritage Site in 2014, the Bonin Islands are packed with unique endemic organisms constantly threatened by invasive species. With this study I hope to make the precious biodiversity and evolutionary significance of the Bonin Islands known, and help conservation efforts by better understanding the natural ecology and behavior of these endemic organisms.