The additive genetic variation (VA) of fitness in a population is of particular importance to quantify its adaptive potential and predict its response to rapid environmental change. Recent statistical advances in quantitative genetics and the use of new molecular tools have fostered great interest in estimating fitness VA in wild populations. However, the value of VA for fitness in predicting evolutionary changes over several generations remains mostly unknown. In our study, we addressed this question by combining classical quantitative genetics with experimental evolution in the model organism Tribolium castaneum (red flour beetle) in three new environmental conditions (Dry, Hot, Hot‐Dry). We tested for potential constraints that might limit adaptation, including environmental and sex genetic antagonisms captured by negative genetic covariance between environments and female and male fitness, respectively. Observed fitness changes after 20 generations mainly matched our predictions. Given that body size is commonly used as a proxy for fitness, we also tested how this trait and its genetic variance (including nonadditive genetic variance) were impacted by environmental stress. In both traits, genetic variances were sex and condition dependent, but they differed in their variance composition, cross‐sex and cross‐environment genetic covariances, as well as in the environmental impact on VA.

中文翻译：

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适应性遗传变异及其跨性别协方差预测实验进化过程中的适应

种群中适应性的加性遗传变异 (VA) 对于量化其适应潜力和预测其对快速环境变化的反应特别重要。数量遗传学的最新统计进展和新分子工具的使用引起了人们对估计野生种群适应度 VA 的极大兴趣。然而，VA 在预测几代进化变化方面的适应值仍然是未知的。在我们的研究中，我们通过将经典数量遗传学与模型生物 Tribolium castaneum（红粉甲虫）在三种新环境条件（干燥、热、热-干燥）中的实验进化相结合来解决这个问题。我们测试了可能限制适应的潜在约束，包括环境和性别遗传拮抗，分别由环境与女性和男性健康之间的负遗传协方差捕获。20 代后观察到的适应度变化主要与我们的预测相符。鉴于体型通常被用作健康的代表，我们还测试了这种性状及其遗传变异（包括非加性遗传变异）如何受到环境压力的影响。在这两个性状中，遗传变异都依赖于性别和条件，但它们的变异组成、跨性别和跨环境遗传协方差以及环境对 VA 的影响不同。我们还测试了这种性状及其遗传变异（包括非加性遗传变异）如何受到环境压力的影响。在这两个性状中，遗传变异都依赖于性别和条件，但它们的变异组成、跨性别和跨环境遗传协方差以及环境对 VA 的影响不同。我们还测试了这种性状及其遗传变异（包括非加性遗传变异）如何受到环境压力的影响。在这两个性状中，遗传变异都依赖于性别和条件，但它们的变异组成、跨性别和跨环境遗传协方差以及环境对 VA 的影响不同。