Collaborative Research: The evolutionary mechanics of hybridization across a primate radiation

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This is an investigation of whether hybridization between closely-related species has been a significant force in the evolution of primates. Recent research has uncovered that up to 5% of the DNA of many modern humans originated from ancient interbreeding with Neanderthal populations, raising the broader question of whether a species' genetic makeup includes genes brought together through occasional episodes of hybridization. In the present study, the genomes of a group of monkey species will be compared to determine whether segments of DNA have been transferred between species over evolutionary time. The project will broaden participation of groups under-represented in science through a partnership with the McNair Scholars Program (a federal program that identifies promising undergraduates who are first-generation, low-income and/or under-represented in PhD programs) and by working with other organizations that focus on similar groups of high school students, such as the Harlem Children's Society, BridgeUp:STEM, and ARISE in New York City. The project will also enhance infrastructure for research by making all custom-written software freely available on the internet and by presenting such software in workshops at the annual conference of H3ABioNet, a pan-African bioinformatics group. Hybridization has been reported among numerous species with the Cercopithecins. Thus, if historical interbreeding indeed leaves its mark on a species' genome, such evidence should be readily identified in these animals and serve as a model system for investigating hybridization in primates. Two central questions will be addressed. First, are genes more likely to be exchanged between closely related species (e.g., within a genus), or species with deep evolutionary separation (e.g., different genera)? The former scenario allows for a higher frequency of hybridization due to greater overall biological similarity, while the latter scenario allows for more variant, and possibly more advantageous, forms of genes to evolve and transfer between species. Second, will genes exchanged through hybridization be unique, or will patterns of genes with similar functions be found to repeatedly cross between species? If the latter, such patterns will reveal a more general pattern by identifying genes that are likely the essential drivers of the evolutionary process in primates. "Consensus" evolutionary relationships among these monkey species will be derived from an analysis of the total non-coding DNA sequence; this amounts to the majority of the genome and reflects the "true" set of evolutionary relationships. Coding sequences will then be analyzed individually and compared across all possible pairs of species; some sequences will follow the consensus pattern, but those that do not will likely reflect genes exchanged through hybridization. A series of statistical calculations will measure the probability of such genes being correctly identified as transfers via hybridization.