The fitness costs of adaptation via phenotypic plasticity and maternal effects
The fitness costs of adaptation via phenotypic plasticity and maternal effects
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DOI：
10.1111/1365-2435.12207
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发表时间：
2014-06-01
影响因子：
5.2
通讯作者：
Hoyle, Rebecca B.
中科院分区：
文献类型：
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作者：
Ezard, Thomas H. G.;Prizak, Roshan;Hoyle, Rebecca B.
表型通常依赖于环境，这就要求有机体跟踪环境变化。生物面临的挑战是如何利用最准确的环境线索来构建表型。在这里，我们使用了一个定量遗传模型，该模型分别由加性遗传方差、通过线性反应规范的代内可塑性和跨代可塑性以及间接遗传效应来实现。我们展示了这些成分对最终表型的相对影响取决于环境变化(快或慢、正弦或随机)的可预测性以及环境感知和选择行为之间的发展滞后。然后，我们将预期平均适应度分解为三个分量(方差负载、适应负载和波动负载)，以研究代内可塑性和跨代可塑性的适应度成本。母体效应系数m为强负时，方差载荷最小，而母体效应系数m为强正时，波动载荷最小。适应项最大值接近于零，在不同的环境情景下，m最好是正的或负的。当tau较短和环境在季节极端之间频繁变化时，表型可塑性较高。预期平均种群适合度最高，远离最高观察到的表型可塑性水平。内可塑性和跨代可塑性协同作用，提供适应良好的表型，这强调了在研究表型进化时同时研究两者的必要性。
Phenotypes are often environmentally dependent, which requires organisms to track environmental change. The challenge for organisms is to construct phenotypes using the most accurate environmental cue.Here, we use a quantitative genetic model of adaptation by additive genetic variance, within- and transgenerational plasticity via linear reaction norms and indirect genetic effects respectively.We show how the relative influence on the eventual phenotype of these components depends on the predictability of environmental change (fast or slow, sinusoidal or stochastic) and the developmental lag tau between when the environment is perceived and when selection acts.We then decompose expected mean fitness into three components (variance load, adaptation and fluctuation load) to study the fitness costs of within- and transgenerational plasticity. A strongly negative maternal effect coefficient m minimizes the variance load, but a strongly positive m minimises the fluctuation load. The adaptation term is maximized closer to zero, with positive or negative m preferred under different environmental scenarios.Phenotypic plasticity is higher when tau is shorter and when the environment changes frequently between seasonal extremes. Expected mean population fitness is highest away from highest observed levels of phenotypic plasticity.Within- and transgenerational plasticity act in concert to deliver well-adapted phenotypes, which emphasizes the need to study both simultaneously when investigating phenotypic evolution.