Data from: The other 96%: can neglected sources of fitness variation offer new insights into adaptation to global change?

Mounting research considers whether populations may adapt to global change based on additive genetic variance in fitness. Yet selection acts on phenotypes, not additive genetic variance alone, meaning that persistence and evolutionary potential in the near-term, at least, may be influenced by other sources of fitness variation, including non-additive genetic and maternal environmental effects. The fitness consequences of these effects, and their environmental sensitivity, are largely unknown. Here, applying a quantitative genetic breeding design to an ecologically-important marine tubeworm, we examined non-additive genetic and maternal environmental effects on fitness (larval survival) across three thermal environments. We found that these effects are non-trivial and environment-dependent, explaining at least 44% of all parentally-derived effects on survival at any temperature, and 96% of parental effects at the most stressful temperature. Unlike maternal environmental effects, which manifested at the latter temperature only, non-additive genetic effects were consistently significant and covaried positively across temperatures (i.e., parental combinations that enhanced survival at one temperature also enhanced survival at elevated temperatures). Thus, while non-additive genetic and maternal environmental effects have long been neglected because their evolutionary consequences are complex, unpredictable, or seen as transient, we argue that they warrant further attention in a rapidly warming world.日益增多的研究围绕种群是否可通过适合度（fitness）的加性遗传变异（additive genetic variance）来适应全球环境变化展开。然而自然选择作用于表型，而非仅作用于加性遗传变异，这意味着至少在短期尺度内，种群存续能力与进化潜力或受其他适合度变异来源影响，包括非加性遗传效应（non-additive genetic effects）与母体环境效应（maternal environmental effects）。目前学界对这些效应的适合度影响及其环境敏感性仍知之甚少。本研究针对一种具有重要生态意义的海洋管虫（marine tubeworm），采用数量遗传育种设计（quantitative genetic breeding design），探究了三种热环境（thermal environments）下非加性遗传效应与母体环境效应对适合度（fitness，即幼虫存活率）的影响。研究结果表明，此类效应并非微不足道且具有环境依赖性：在任意温度条件下，它们至少可解释亲本来源存活率效应的44%；在最具胁迫性的温度环境下，这一比例高达96%。与仅在该胁迫温度下显现的母体环境效应不同，非加性遗传效应始终显著，且在各热环境间呈正相关——即能提升某一温度下幼虫存活率的亲本组合，同样可在高温环境下提升存活率。因此，尽管非加性遗传效应与母体环境效应因其进化效应复杂、难以预测或被视为短暂性效应而长期被忽视，但我们认为，在全球快速变暖的背景下，这类效应值得学界进一步关注。