Effective size of a fluctuating age-structured population
Effective size of a fluctuating age-structured population
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DOI：
10.1534/genetics.104.028233
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发表时间：
2005-06-01
期刊：
影响因子：
3.3
通讯作者：
Saether, BE
中科院分区：
文献类型：
--
作者：
Engen, S;Lande, R;Saether, BE
以前关于年龄结构人口有效规模的理论假设了一个恒定的环境，通常是恒定的人口规模和年龄结构。我们推导了受年龄结构和总人口规模波动影响的人口有效规模的方差公式，这些波动是由人口和环境随机性的组合产生的。分析了单倍体和雌雄同株或雌雄异株的二倍体种群。利用随机人口学的最新结果，导出了总种群大小N和选择性中性等位基因频率p的联合动力学的二维扩散近似。p的无穷小方差乘以世代时间，得到了每代有效种群大小的表达式。这取决于N的当前值、世代时间、人口随机性和孟德尔分离造成的遗传随机性，但与环境随机性无关。在较长的时间间隔内，有效种群大小的公式结合了确定性增长和环境随机性，以解释N的变化。
Previous theories on the effective size of age-structured populations assumed a constant environment and, usually, a constant population size and age structure. We derive formulas for the variance effective size of populations subject to fluctuations in age structure and total population size produced by a combination of demographic and environmental stochasticity. Haploid and monoecious or dioecious diploid populations are analyzed. Recent results from stochastic demography are employed to derive a two-dimensional diffusion approximation for the joint dynamics of the total population size, N, and the frequency of a selectively neutral allele, p. The infinitesimal variance for p, multiplied by the generation time, yields an expression for the effective population size per generation. This depends on the current value of N, the generation time, demographic stochasticity, and genetic stochasticity due to Mendelian segregation, but is independent of environmental stochasticity. A formula for the effective population size over longer time intervals incorporates deterministic growth and environmental stochasticity to account for changes in N.