Institute of Zoology, Zoological Society of London, Regent's Park, London NW1 4RY, United Kingdom.
Evolution. 2010 Jun;64(6):1704-18. doi: 10.1111/j.1558-5646.2010.00953.x. Epub 2010 Jan 20.
Many long-lived plant and animal species have nondiscrete overlapping generations. Although numerous models have been developed to predict the effective sizes (N(e)) of populations with overlapping generations, they are extremely difficult to apply to natural populations because of the large array of unknown and elusive life-table parameters involved. Unfortunately, little work has been done to estimate the N(e) of populations with overlapping generations from marker data, in sharp contrast to the situation of populations with discrete generations for which quite a few estimators are available. In this study, we propose an estimator (EPA, estimator by parentage assignments) of the current N(e) of populations with overlapping generations, using the sex, age, and multilocus genotype information of a single sample of individuals taken at random from the population. Simulations show that EPA provides unbiased and accurate estimates of N(e) under realistic sampling and genotyping effort. Additionally, it yields estimates of other interesting parameters such as generation interval, the variances and covariances of lifetime family size, effective number of breeders of each age class, and life-table variables. Data from wild populations of baboons and hihi (stitchbird) were analyzed by EPA to demonstrate the use of the estimator in practical sampling and genotyping situations.
许多长寿的植物和动物物种具有不连续的重叠世代。尽管已经开发出许多模型来预测具有重叠世代的种群的有效大小 (N(e))，但由于涉及大量未知和难以捉摸的生命表参数，这些模型极难应用于自然种群。不幸的是，很少有工作致力于从标记数据估计具有重叠世代的种群的 N(e)，与具有离散世代的种群形成鲜明对比，后者有相当多的估计器可用。在这项研究中，我们提出了一种使用从种群中随机抽取的单个个体的性别、年龄和多位点基因型信息来估计具有重叠世代的种群当前 N(e)的估计器（通过亲代分配的估计器，EPA）。模拟表明，EPA 在现实的抽样和基因分型工作下提供了对 N(e) 的无偏和准确估计。此外，它还可以估计其他有趣的参数，如世代间隔、终生家庭大小的方差和协方差、每个年龄组的有效繁殖者数量以及生命表变量。通过 EPA 对狒狒和 hihi（缝叶莺）的野生种群数据进行了分析，以展示在实际的抽样和基因分型情况下使用该估计器的情况。
