《群体遗传学》课件.ppt

Chapter 11 Inheritance analysis of population and evolution群体遗传学 Population genetics A branch discipline of genetics to investigate the genetic structure and variation of popualtions; that is, the discipline within genetics studies that changes in gene and genotype frequencies, and the factors that alter the frequencies such as selection, mutation, migration, as well as random genetic drift by the mathematical and statistical method, thus to explore the mechanism of biology evolution 群体遗传学 一门研究群体的遗传结构及其变化规律的遗传学分支学科，应用数学和统计学的方法研究在群体中的基因频率和基因型频率以及影响这些频率的选择效应和突变作用、迁移和遗传漂变作用与遗传结构的关系，由此来探讨进化的机制 Population and gene pools群体与基因库 Genotype frequency基因型频率 Calculating allele frequency等位基因频率计算 The Hardy-Winberg Law哈德-温伯格定律 1. The frequency of alleles does not change from generation to generation; in other words, the population does not evolve 2. After one generation of random mating, offspring genotype frequencies can be predicted from the parent allele frequencies 一、等位基因频率没有改变，代代相传。换句话说，群体不进化 二、 经过一个世代的随机交配，后代基因型频率可以从亲代等位基因频率进行预测，并保持平衡 A set of simple assumptions假设条件 There is no selection There is no mutation There is no migration The population is infinitely large Individuals in the population mate randomly 没有选择 没有突变 没有迁移 群体无限大 群体中的个体随机交配 The general case of allele and genotype frequencies等位基因和基因型频率 the Hardy-weinberg law: calculating heterozygote frequency基于哈德-温伯格计算杂合子频率 Extension of the Hardy-Weinberg law哈德-温伯格定律的扩展 The equilibrium of multiple allele Factors that alter allele frequencies in population改变群体等位基因频率的因素 In nature, population are dynamic, and change in size and gene pool are common, which meet the assumptions of random mating, absence of selection and mutation, and equal viability and fertility 在自然界中，群体是动态的，其规模和基因库的变化是常见的，符合在随机交配，选择和突变，有同等生存能力和生育能力的情况下的假设 Natural election自然选择 Natural election force Mutation突变 Forward and reverse-ward mutation正向和反向突变 在没有其他因素影响时：设某一世代中，等位基因A, a的频率分别为 P(A)=p, P(a)=q 正反突变率分别为u、v，则： u