Molecular Approach to the Phylogeny of Primates and Other Placental Mammals

尽管在阐明 胎盘哺乳动物的生殖和系统学，许多困难 问题仍然存在。 这些问题不仅涉及秩序 灵长类动物，其中有人类的成员，但也有17个其他 胎盘哺乳动物的一个目。 例如，一个最 一个重要的灵长类群体是Ceboidea超家族， 新大陆的猴子和绒猴，但是进化的模式 在过去的2500万年里， 这些新热带灵长类动物的16个幸存属 明白 类似地，一系列系统发育分支事件 发生在9000万到6500万年前， 现存的胎盘哺乳动物的订单，但 分支的确切过程，即进化关系 在这些主要的胎盘哺乳动物中， 明确确立。 分子生物学技术进展 生物学使得获取大量DNA成为可能 来自广泛范围内的相应基因的核苷酸序列数据 物种。 由于DNA中的核苷酸序列是遗传的， 或遗传物质，这些信息提供了一个非常精确的 记录了被比较物种的进化关系。 通过利用新的分子方法产生 比较核苷酸序列数据，DNA信息，从几个 不同的基因将从上述哺乳动物中获得 组 这些数据将受到严格的系统发育 分析，使用基于理论模型的计算机程序， 最能描述基因随时间变化的过程。 这种系统发育分析，当应用于DNA序列时， 来自基因中进化更快的部分的数据， 有望提供一个高分辨率的进化图， 新热带区16个属之间的关系 灵长类动物 同样，这种分析也适用于旋转速度较慢的 基因部分应该提供一个很好的解决图片的 存在于18个目之间的进化关系 胎盘哺乳动物 除了重建 系统发育分支，DNA变化率沿着分支将 下定决心。 这些关于利率的信息，当与 动物生活史策略的知识包括 在这项研究中，将测试生活史改变的假设， 更长的世代时间和寿命会导致 DNA突变率，而生命史的变化朝着更短 代次和寿命导致DNA突变的增加 rates.

Although much progress has been made in elucidating the phylogeny and systematics of placental mammals, many difficult problems still remain. These problems involve not only the order Primates, which has humans among its members, but also the 17 other orders of placental mammals. For example, one of the most important primate groups is the superfamily Ceboidea comprised of New World monkeys and marmosets, but the pattern of evolution over the last 25 million years that led from a common ancestor to the 16 surviving genera of these neotropical primates is poorly understood. Similarly, a series of phylogenetic branching events that occurred between 90 and 65 million years ago separated the 18 surviving orders of placental mammals from one another, but the exact course of branching, i.e. the evolutionary relationships among these major groups of placental mammals, has yet to be definitively established. Recent technical advances in molecular biology have made it possible to obtain large amounts of DNA nucleotide sequence data from corresponding genes in a wide range of species. Since the sequence of nucleotide in DNA is the genetic or heritable material, such information provides a very precise record of the evolutionary relationships of the species compared. Through utilizing the new molecular methods for generating comparative nucleotide sequence data, DNA information from several different genes will be obtained from the above mentioned mammalian groups. These data will be subjected to rigorous phylogenetic analysis, using computer programs based on theoretical models that best describe the course of genetic change over time. This phylogenetic analysis, when applied to the DNA sequence data from the more rapidly evolving portions of the genes, is expected to provide a highly resolved picture of the evolutionary relationships that exist among the 16 genera of neotropical primates. Similarly, this analysis applied to the slower revolving genic portions should provide a well resolved picture of the evolutionary relationships that exist among the 18 orders of placental mammals. In addition to reconstructing the pattern of phylogenetic branching, rates of DNA change along the branches will be determined. This information on rates, when related to knowledge on the life history strategies of the animals included in the study, will test the hypothesis that life history changes towards longer generation times and life spans cause decreases in DNA mutation rates, whereas life history changes towards shorter generation times and life spans cause increases in DNA mutation rates.