Null Models in Molecular Phylogenetic Systematics

分子系统发育系统学中的零模型

• 批准号: 8918042
• 负责人: James Archie
• 金额: --
• 依托单位: California State University-Long Beach Foundation
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1990
• 资助国家: 美国
• 起止时间: 1990-03-01 至 1994-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8918042&HistoricalAwards=false
• 关键词: Null; Models; Molecular; Phylogenetic; Systematics

Dr. Archie will examine patterns of evolution of DNA sequences in a broad array of organisms. Through the use of information in DNA sequence databases, the emphasis of the research will be on the evaluation of levels of accumulated random substitutions within DNA sequences and an examination of how these substitutions affect our ability to analyze sequence data. It has been generally acknowledged that DNA sequences contain a large amount of information on the evolutionary history of living organisms that can be used to make inferences about relationships among species. However, it is recognized that these sequences contain a large amount of random information because of the nature of the origin of change at sites in the sequences and because each site can take only four different forms. In previous research, biologists have assumed that there is substantial residual information in the sequences, a by- product of the evolutionary history of the organisms, that could be decoded using modern methods of analysis through the incorporation of computers. However, the methods for the analysis of these data break down and produce less certain results as the level of randomness increases. Levels of randomness are expected to vary between different regions of the DNA within the nucleus as well as in nucleotide sequences outside of the nucleus and are expected to increase as the amount of time since divergence between the species being analyzed increases. Since many species and species groups being compared have diverged over millions, tens of millions, or even hundreds of millions of years, in many comparisons of sequences biologists expect substantial amounts of random information about the evolutionary history to be present in the sequence data. The research program will analyze levels of random sequence information for a variety of different groups of organisms and for different areas in the genome. It will rely on sequence information that is present in DNA and protein sequence databases for information. These databases are growing rapidly in size because of recent technological advances in molecular biology. The sensitivity of a variety of numerical techniques for analyzing sequence data due to the accumulation of random information will be examined. Several new analytical techniques have been developed over the last 2-3 years and have generated a substantial amount of interest. However, neither these nor the older techniques have been examined from the perspective to be used in this research. The results from the study will help to indicate which sequences and parts of sequences will be useful for inferring relationships among species and species groups by identifying regions of the genome that tend to accumulate evolutionary useful and random changes at different rates. The results will also help indicate the lengths of sequences that must be examined in order to make reasonable inferences about evolutionary relationships.

阿奇博士将研究DNA的进化模式 一系列生物体的基因序列。 通过使用 DNA序列数据库中的信息， 研究将是对积累的水平的评估， DNA序列内的随机替换和 这些替换如何影响我们分析序列的能力 数据 人们普遍认为，DNA序列 包含了大量的进化历史信息 可以用来推断 物种之间的关系。 然而，人们认识到， 这些序列包含大量的随机信息 由于在网站的变化起源的性质， 因为每个位点只能接受四种不同的 forms.在以前的研究中，生物学家假设， 是序列中的大量残余信息， 生物进化史的产物， 使用现代分析方法进行解码， 合并计算机。 然而， 对这些数据的分析会崩溃并产生不太确定的结果 随着随机性水平的增加而产生。 水平 随机性预期在不同区域之间变化， 核内的DNA以及核外的核苷酸序列 随着时间的推移， 因为被分析的物种之间的差异增加。 由于许多物种和物种群被比较， 分歧超过数百万，数千万，甚至数百万， 数百万年来，在生物学家的许多序列比较中， 期望大量的随机信息， 进化历史存在于序列数据中。 该研究计划将分析随机序列的水平 各种不同生物群体的信息， 基因组的不同区域。 它将依赖于序列 存在于DNA和蛋白质序列数据库中的信息 获取信息 这些数据库的规模正在迅速增长 因为最近分子生物学的技术进步。 各种数值技术的灵敏度， 分析序列数据由于随机的积累， 信息将被检查。 几种新的分析技术 在过去的2-3年里， 大量的兴趣。 然而，无论是这些还是 旧的技术已经被检查的角度是 在这项研究中使用。 研究结果将有助于 指示哪些序列和序列的部分将是有用的 用于推断物种和物种群之间的关系， 识别基因组中易于积累的区域 以不同的速率进化有用和随机的变化。 的 结果还将有助于指示序列的长度， 必须进行审查，以便作出合理的推论， 进化关系。