Data from: Environmental stress correlates with increases in both genetic and residual variances: a meta-analysis of animal studies

Adaptive evolutionary responses are determined by the strength of selection and the amount of genetic variation within traits, however, both are known to vary across environmental conditions. As selection is generally expected to be strongest under stressful conditions, understanding how the expression of genetic variation changes across stressful and benign environmental conditions is crucial for predicting the rate of adaptive change. While theory generally predicts increased genetic variation under stress, previous syntheses of the field has found limited support for this notion. These studies have focused on heritability, which is dependent on other environmentally sensitive, but non-genetic, sources of variation. Here, we aim to complement these studies with a meta-analysis where we examine changes in coefficient of variation (CV) in maternal, genetic, and residual variances across stressful and benign conditions. Confirming previous analyses, we did not find any clear direction in how heritability changes across stressful and benign conditions. However, when analyzing CV, we found higher genetic and residual variance under highly stressful conditions in life-history traits but not in morphological traits. Our findings are of broad significance to contemporary evolution suggesting that rapid evolutionary adaptive response may be mediated by increased evolutionary potential in stressed populations.适应性进化响应由选择强度与性状内遗传变异量共同决定，而众所周知，这两个因素均会随环境条件发生变化。鉴于一般认为选择在胁迫环境下强度最高，因此解析遗传变异的表达模式如何随胁迫与良性环境发生改变，对预测适应性进化速率至关重要。尽管理论通常预测胁迫环境下遗传变异会增加，但该领域此前的综合综述研究却发现支持这一观点的证据有限。这些研究均聚焦于遗传力（heritability），而遗传力依赖于其他对环境敏感的非遗传变异来源。为此，我们通过一项荟萃分析（meta-analysis）对这些研究进行补充，旨在解析胁迫与良性环境下母体方差、遗传方差及残差方差的变异系数（coefficient of variation, CV）变化情况。与此前的分析结果一致，我们未发现遗传力随胁迫与良性环境变化存在明确趋势。不过，在对变异系数进行分析时，我们发现生活史性状（life-history traits）在强胁迫环境下的遗传方差与残差方差更高，但形态性状（morphological traits）并未呈现这一规律。本研究结果对当代进化研究具有广泛意义，表明快速进化的适应性响应或可通过胁迫种群中提升的进化潜力介导实现。