Evolutionary History of Subfossil Lemurs as Determined by Ancient DNA Analysis

通过古代 DNA 分析确定亚化石狐猴的进化史

• 批准号: 9905614
• 负责人: Anne Yoder
• 金额: $ 21.04万
• 依托单位: Northwestern University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-08-01 至 2002-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9905614&HistoricalAwards=false
• 关键词: Evolutionary; History; Subfossil; Lemurs; Determined

The primary goal of this research is to derive a molecular evolutionary history of Madagascar's extinct giant lemurs using DNA from the maternally-inherited mitochondrion (mtDNA). The subfossil lemurs represent extremes in body size and morphology and are thus evolutionary enigma. All of the species to be included in the study have been extinct for approximately 1000 years, leaving only their skeletalremains for scholarly analysis. Recent studies have shown that if the preservational environment has been favorable, DNA often persists for many thousands of years and can be retrieved for phylogenetic analysis. These "ancient DNA" techniques will be employed to generate mtDNA sequence data from two protein-coding genes (cytochrome b and cytochrome oxidase subunit II) and from the mitochondrial control region (D-loop). The acquired sequences will be analyzed both as separate data sets and as a combined mtDNA data set. As a long-term goal, the genetic data will be combined with morphological data and analyzed with maximum parsimony. This strategy for phylogenetic resolution has proven to be highly informative for extant Malagasy primates and thus promises similar resolution for the extinct taxa. The results of the study will be significant for reconstructing the biogeographic history of Madagascar as well as for understanding morphological and ecological evolution in one of the world's most diverse assemblages of mammals. Moreover, the technical challenges and successes specific to this study will add to the growing body of knowledge germane to ancient DNA methods. Preliminary activity has demonstrated that intrinsic DNA, though highly-fragmented, exists in sufficient quantities to be extracted, amplified, and sequenced in many if not all subfossil lemurs. The legitimacy of these data has been confirmed in an independent laboratory. Most significantly, the promise of clear evolutionary resolution is evident from analysis of these preliminary data.

这项研究的主要目标是利用来自母体遗传线粒体（mtDNA）的DNA推导出马达加斯加已灭绝的巨型狐猴的分子进化史。亚化石狐猴代表了体型和形态的极端，因此是进化的谜。所有被纳入研究的物种都已经灭绝了大约1000年，只留下了它们的骨架供学术分析。最近的研究表明，如果保存环境有利，DNA通常可以保存数千年，并且可以用于系统发育分析。这些“古DNA”技术将用于从两个蛋白质编码基因（细胞色素b和细胞色素氧化酶亚基II）和线粒体控制区（D-loop）生成mtDNA序列数据。所获得的序列将作为单独的数据集和组合的mtDNA数据集进行分析。作为一个长期目标，遗传数据将与形态学数据相结合，并以最大限度的简约进行分析。这种系统发育分辨率的策略已被证明对现存的马达加斯加灵长类动物具有很高的信息量，因此有望对已灭绝的分类群进行类似的分辨率。这项研究的结果对于重建马达加斯加的生物地理历史，以及了解世界上最多样化的哺乳动物群落之一的形态和生态进化具有重要意义。此外，这项研究的技术挑战和成功将增加与古代DNA方法相关的知识体系。初步研究表明，尽管内在DNA高度碎片化，但在许多（如果不是全部的话）狐猴亚化石中存在足够数量的DNA，可以提取、扩增和测序。这些数据的合法性已在一个独立的实验室得到证实。最重要的是，从对这些初步数据的分析来看，明确进化解决方案的前景是显而易见的。