Reproductive Value and Fluctuating Selection in an Age-Structured Population
Reproductive Value and Fluctuating Selection in an Age-Structured Population
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DOI：
10.1534/genetics.109.105841
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发表时间：
2009-10-01
期刊：
影响因子：
3.3
通讯作者：
Saether, Bernt-Erik
中科院分区：
文献类型：
--
作者：
Engen, Steinar;Lande, Russell;Saether, Bernt-Erik
由环境随机性引起的年龄结构的波动在人口规模和等位基因频率上产生自相关和瞬时波动，这使人口统计学和进化分析复杂化。根据Fisher的建议，我们表明，加权不同年龄的个体的生殖值作为一个过滤器，消除时间自相关的人口统计和进化，由于随机年龄结构。假设弱选择，随机交配，和一个平稳的环境分布，没有自相关，我们推导出一个扩散近似的生殖值加权等位基因频率的演变。预期的进化服从由种群的长期增长率定义的自适应地形。基因型的期望适应度是它在平均环境中的马尔萨斯适应度减去它的增长率与种群增长率的协方差。年龄结构模型的模拟验证了扩散近似的准确性。我们开发了一种统计方法，用于测量在波动的年龄结构群体中生殖值加权等位基因频率的预期选择。
Fluctuations in age structure caused by environmental stochasticity create autocorrelation and transient fluctuations in both population size and allele frequency, which complicate demographic and evolutionary analyses. Following a suggestion of Fisher, we show that weighting individuals of different age by their reproductive value serves as a filter, removing temporal autocorrelation in population demography and evolution due to stochastic age structure. Assuming weak selection, random mating, and a stationary distribution Of environments with no autocorrelation, we derive a diffusion approximation for evolution of the reproductive value weighted allele frequency. The expected evolution obeys an adaptive Lopography defined by the long-run growth rate of the population. The expected fitness of a genotype is its Malthusian fitness in the average environment minus the covariance of its growth rate with that Of the Population. Simulations of the age-structured model verify the accuracy of the diffusion approximation. We develop statistical methods for measuring the expected selection on the reproductive value weighted allele frequency in a fluctuating age-structured population.