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这是种群生态学ppt，包括了概论，种群的基本特征，生命表的特征和应用，种群增长，种群调节，种群进化对策等内容，欢迎点击下载。
种群生态学ppt是由红软PPT免费下载网推荐的一款课件PPT类型的PowerPoint.
第二章 种群生态学 Population Ecology We will focus on…. 概论 §1 种群的基本特征 §2 生命表的特征和应用 §3 种群增长 §4 种群调节 §5 种群进化对策 1. 种群的概念 Population诠释 Different attributes between individual and population Metapopulation 集合种群 4. 种群生态学 研究方法： 理论模型 第一节 种群的基本特征 密度及调查方法： 种群动态的基本参数： 出生率； 死亡率； 迁移； 性比； 年龄结构； 空间分布型； 种群的遗传结构. 1. Population Density（种群密度） 绝对密度 Absolute density 相对密度 Relative density Absolute density mark- recapture method 假设前提 捕捉努力量相等时，每次捕捉个体数正比于当时种群大小（捕捉比例恒定）； 随着残留个体减少，累计移除个体数增加；但单位捕捉努力所获得个体数减少； 2. Basic parameters on population dynamics Factors affecting natality 3. 性比 Sexual ratio 4. 年龄结构 Age distribution 5. 空间分布型 Distribution pattern How organisms are spaced in the area Intensity and grain of population clumps 集群强度：集群间密度变化幅度。高则强度大。 集群粒性：集群大小及彼此间距离。 粗粒型：集群大且群间距离远； 细粒型: （相反） Characteristics of the 3 spatial patterns Distinguish the 3 patterns 1). Hardy-Weinberg equilibrium 哈迪-温伯格平衡 For a pair of alleles A & a if p = frequency of allele A q = frequency of allele a p + q = 1， (p + q)2 =1 p2 + 2pq + q2 =1 ( equilibrium state) if only law of probability affects the frequency with which gametes（接合体） combine to form new individuals. AND Under following conditions: Bisexual population Large population Random mating No mutation Migration ~ 0 Natural selection does not affect the locus（选择中性） Example If only 6% of the population displays pale eyes (recessive gene e). What is the frequency of genotype Ee in this population? q2 = 0.06 q = 0.24 p + q = 1 p = 0.76 Ee = 2pq = 2(0.76)(0.24) = 0.36 2). Genetic variation， diversity or polymorphism Maintenance of balanced polymorphism (vs. transitional or directional polymorphism) Heterosis（杂种优势） diversifying evolution frequency-dependent selection selective forces operating in different directions within different patches of a fine mosaic in the population Isolation mechanism Pre-zygotic: habitat， temporal， ethological， mechanical Geographic isolates – semi-isolated populations prevented by some extrinsic barriers from a free flow of genes. Breeding isolates Post-zygotic hybrid inviability or weakness hybrid sterility F2 breakdown 4). Reduction in variation Inbreeding Bottlenecks Founder effect Genetic drift- random shifts in allele frequencies 5). Effect of small populations More demographic variation， inbreeding depression， genetic drift → higher risk of extinction. Effective population size ( Ne) The size of a genetically idealized population with which an actual population can be equated genetically， Ne = N ， if equal sex ratio equal probability of mating constant dispersal rate progeny (后裔) per family randomly distributed 6). Effect of continental drift Distribution/radiation of monotremes （单孔类动物）and marsupials(有袋动物) 7). Extinction and its causes Natural causes: climatic changes and stochastic event Human disturbance habitat alteration over-exploitation exotic species diseases and other factors Review
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