RPG: Phylogeny and Evolution of Mitochondrial DNA in ExtinctMalagasy Primates

拟议的研究项目将利用古dna （a - dna）技术来了解灭绝灵长类动物的进化起源和消亡。线粒体DNA将被提取、扩增和测序，用于亚化石马达加斯加狐猴的综合样本。待测样本的年龄范围从距今约650年到距今1万多年不等。DNA序列将通过系统发育、分子进化和种群遗传的方法进行分析，以重建体型较大的灭绝狐猴相对于体型较小的现存狐猴的进化关系，并研究导致这些独特哺乳动物灭绝的力量。单一物种谱系中时间间隔DNA序列的比较将允许“实时”观察分子进化模式，从而为分子进化领域提供一个新的视角。研究DNA序列和结构随时间的变化（即分子进化）是一个越来越有价值的科学研究领域。这些研究应用于多种领域，如有机病原体（如艾滋病病毒）的分析和控制、生物地理学、系统发育学、生理学和保护生物学——仅举几例。在A-DNA研究人员群体中正在开发的技术使科学家能够直接观察DNA结构的变化，而这些变化以前仅限于通过比较活生物体的DNA来推断。尽管没有真正的理论或概念原则将a - dna学科统一起来，但所采用的实验室方法的严格性和难度创造了一个研究人员社区，对他们来说，相互交流是必不可少的。拟议的研究将增加这一不断增长的知识体系，并将从灭绝的非人类灵长类动物中产生前所未有的DNA序列数据。问题将在宏观和微观进化水平上解决，从而超越“技术好奇心”来分析更大的问题。首先，该项目将有助于恢复所有马达加斯加特有灵长类动物的系统发育。这一目标的实现对于了解马达加斯加和非洲的生物地理历史，以及了解极其多样化的哺乳动物群体的形态和生态进化具有重要意义。其次，该项目将允许对突变率和核苷酸取代模式等分子进化现象进行细粒度分析。第三，在已知的灭绝窗口中对种群内遗传多样性进行时间间隔采样，可以通过识别遗传同质性的危险水平来指导未来的保护工作。

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.