复旦大学上海医学院：《医学遗传学 Medical Genetics》精品课程PPT教学课件（八年制）08 基因变异的群体行为 Population Genetics

08基因变异的 群体行为 Population genetics

08基因变异的 群体行为 Population Genetics

What is a population from a genetic perspective? A population in the genetic sense, is not just a group of individuals, but a breeding group

What is a population from a genetic perspective? A population in the genetic sense, is not just a group of individuals, but a breeding group

血是 CHILDREN OF DIFFERENT NATIONALITIES AT BINGAPORE Ts HE S.P. C. beran work in the district of Singapor in )oil 不同人种

不同人种

队制圆 我国不同民族人群

我国不同民族人群

The genetics of a population is concerned not only with the genetic constitution of the individuals but also with the transmission of the genes from one generation to the next

The genetics of a population is concerned not only with the genetic constitution of the individuals but also with the transmission of the genes from one generation to the next

Goals of Population Genetics 1. To describe how the frequency of an allele Which controls a trait changes over time 2. To analyze the factors that lead to changes in gene(allele) frequencies 3. To determine how changes in gene(allele) frequencies affect evolution and speciation

Goals of Population Genetics 1. To describe how the frequency of an allele which controls a trait changes over time； 2. To analyze the factors that lead to changes in gene (allele) frequencies； 3. To determine how changes in gene (allele) frequencies affect evolution and speciation

Why Study Populations and Gene Frequencies Genetic variability necessary for evolutionary success, 2. Measuring genetic variability at many loci can characterize a population 3. Variability of phenotypic and molecular traits are analyzed

Why Study Populations and Gene Frequencies 1. Genetic variability necessary for evolutionary success; 2. Measuring genetic variability at many loci can characterize a population; 3. Variability of phenotypic and molecular traits are analyzed

Genetic data for a population can be expressed as gene or allelic frequencies All genes have at least two alleles Summation of all the allelic frequencies for a population can be considered a description of the population 4. Frequencies can vary widely among the alleles in a population 5. Two populations of the same species do not have to have the same allelic frequencies

1. Genetic data for a population can be expressed as gene or allelic frequencies; 2. All genes have at least two alleles; 3. Summation of all the allelic frequencies for a population can be considered a description of the population; 4. Frequencies can vary widely among the alleles in a population; 5. Two populations of the same species do not have to have the same allelic frequencies

群体的遗传平衡 Hardy-Weinberg平衡律 在随机婚配的大群体中,没有受到外在因 素影响的情况下,显性性状并没有随着隐性性 状的减少而增加,不同基因型相互比例在一代 代传递中保持稳定

群体的遗传平衡 一、Hardy-Weinberg平衡律 在随机婚配的大群体中，没有受到外在因 素影响的情况下，显性性状并没有随着隐性性 状的减少而增加，不同基因型相互比例在一代 代传递中保持稳定

Hardy- Weinberg平衡律 第一代的两个等位基因频率和基因型频率 精子 A( p 卵A(p) Aa(p2) Aa(pg) q Aa aa (a2)

Hardy-Weinberg平衡律 第一代的两个等位基因频率和基因型频率 精 子 A（p） a（q） 卵 A（p） AA（p²） Aa（pq） 子 a（q） Aa（pq） aa（q²）