RPG: Phylogeny and Evolution of Mitochondrial DNA in ExtinctMalagasy Primates

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Yoder 9707559 RPG The proposed research project will exploit ancient-DNA (A-DNA) techniques in order to understand the evolutionary origins and demise of a diverse assemblage of extinct primates. Mitochondrial DNA will be extracted, amplified, and sequenced for a comprehensive sample of subfossil Malagasy lemurs. The samples to be tested range in age from approximately 650 years before present (b.p.) to more than 10,000 years b.p. DNA sequences will be analyzed with phylogenetic, molecular evolutionary, and population genetic methods in order to reconstruct the evolutionary relationships of the large-bodied extinct lemurs relative to the smaller-bodied extant lemurs and in order to investigate the forces that led to the extinction of these unique mammals. The comparison of time-interval DNA sequences within a single species lineage will permit the observation of molecular evolutionary patterns in "real time", thus contributing a novel perspective to the field of molecular evolution. The study of changes in DNA sequence and structure over time (i.e.,molecular evolution) is an increasingly valuable field of scientific investigation. Such studies have applications for fields as diverse as the analysis and control of organic pathogens (e.g., the AIDS virus), biogeography, phylogenetics, physiology, and conservation biology --- just to name a few. The techniques that are being developed within the community of A-DNA researchers permit scientists to directly observe changes in DNA structure that had previously been confined to the realm of extrapolation through the comparison of DNA from living organisms.Although there is no real theoretical or conceptual principle that unites the A-DNA discipline, the stringency and difficulty of the laboratory methods that are employed has created a community of researchers for whom intercommunication is essential. The proposed research will add to this growing body of knowledge and will generate an unprecedented amount of DNA seque nce data from extinct, non-human primates. Questions will be addressed on both macro- and microevolutionary levels, thereby going beyond "technological curiosity" to analyze larger questions. First, the project will contribute to the goal of recovering the phylogeny of all endemic Malagasy primates. The achievement of this goal is significant for understanding the biogeographic history of Madagascar and Africa as well as for understanding morphological and ecological evolution in an extremely diverse assemblage of mammals. Second, the project will allow a fine-grained analysis of molecular-evolutionary phenomena such as mutation rate and patterns of nucleotide substitutions. Third, time-interval sampling of intra-population genetic diversity throughout a known extinction window could help guide future conservation efforts by identifying dangerous levels of genetic homogeneity.