Data from: Genetic monitoring reveals temporal stability over 30 years in a small, lake resident brown trout population

Knowledge of the degree of temporal stability of population genetic structure and composition is important for understanding microevolutionary processes and for addressing issues on human impact on natural populations. We know little about how representative single samples in time are to reflect population genetic constitution. We explore the temporal genetic variability patterns over a 30-year period of annual sampling of a lake resident brown trout (Salmo trutta) population, covering 37 consecutive cohorts and five generations. Levels of variation remain largely stable over this period with no indication of substructuring within the lake. We detect genetic drift, however, and the genetically effective population size (Ne) was assessed from allele frequency shifts between consecutive cohorts using an unbiased estimator that accounts for the effect of overlapping generation. The overall mean Ne is estimated as 74. We find indications that Ne varies over time, but th ere is no obvious temporal trend. We also estimated Ne using a one-sample approach based on linkage disequilibrium (LD) not accounting for the effect of overlapping generations. Combining one-sample estimates for all years gives an Ne estimate of 76. This similarity between estimates may be coincidental or reflecting a general robustness of the LD approach to violations of the discrete generations assumption. In contrast to the observed genetic stability, body size and catch per effort have increased over the study period. Estimates of annual effective number of breeders (Nb) correlated with catch per effort suggesting that genetic monitoring can be used for detecting fluctuations in abundance.明晰种群遗传结构与组成的时间稳定性程度，对于理解微进化过程、解析人类活动对自然种群的影响具有重要意义。目前我们对单次时间采样能否代表性地反映种群遗传组成的程度尚所知甚少。本研究针对某湖泊定居型褐鳟（Salmo trutta）种群开展了为期30年的年度采样，覆盖连续37个同生群与5个世代，以此探究其30年间的时间尺度遗传变异模式。此期间种群遗传变异水平整体保持稳定，未检测到湖内存在遗传亚结构。不过本研究仍检测到了遗传漂变现象；我们采用一种可校正世代重叠效应的无偏估计量，通过连续同生群间的等位基因频率偏移估算了有效种群大小（Ne）。整体平均Ne估算值为74。研究结果显示Ne随时间存在波动，但未呈现显著的时间趋势。我们还采用了基于连锁不平衡（LD）的单样本方法估算Ne，该方法未校正世代重叠效应。整合所有年份的单样本估算结果，得到的Ne估算值为76。两种估算结果的相近性或属偶然，也可能反映出连锁不平衡方法对违背离散世代假设的情况具有普遍稳健性。与观测到的遗传稳定性形成对比的是，研究期间种群的个体体长与单位捕捞努力量渔获量均呈上升趋势。年度有效繁殖种群大小（Nb）的估算值与单位捕捞努力量渔获量呈显著相关，这表明遗传监测可用于探测种群丰度的波动。