Evolution and Ecology, University of California, Davis, Davis, CA, USA.
Evolution, Ecology and Behavior, University of Illinois at Urbana-Champaign, Urbana, Il, USA.
Oecologia. 2020 Dec;194(4):585-596. doi: 10.1007/s00442-020-04792-9. Epub 2020 Oct 30.
Empirical studies of phenotypic plasticity often use an experimental design in which the subjects in experimental treatments are exposed to cues, while the subjects in control treatments are maintained in the absence of those cues. However, researchers have virtually ignored the question of what, if any, information might be provided to subjects by the absence of the cues in control treatments. We apply basic principles of information-updating to several experimental protocols used to study phenotypic plasticity in response to cues from predators to show why the reliability of the information provided by the absence of those cues in a control treatment might vary as a function of the subjects' experiences in the experimental treatment. We then analyze Bayesian models designed to mimic fully factorial experimental studies of trans and within-generational plasticity, in which parents, offspring, both or neither are exposed to cues from predators, and the information-states of the offspring in the different groups are compared at the end of the experiment. The models predict that the pattern of differences in offspring information-state across the four treatment groups will vary among experiments, depending on the reliability of the information provided by the control treatment, and the parent's initial estimate of the value of the state (the parental Prior). We suggest that variation among experiments in the reliability of the information provided by the absence of particular cues in the control treatment may be a general phenomenon, and that Bayesian approaches can be useful in interpreting the results of such experiments.
实证研究中，表型可塑性通常采用实验设计，实验组的个体暴露于信号刺激下，对照组的个体则不接触这些信号刺激。然而，研究者几乎忽略了一个问题，即对照组中不接触信号刺激会向个体传递何种信息。我们应用信息更新的基本原理，分析了几个用于研究对捕食者信号的表型可塑性的实验方案，揭示了为什么控制组中不接触这些信号刺激所提供的信息的可靠性可能会随个体在实验组中的经历而变化。然后，我们分析了旨在模拟跨代和代内可塑性的完全析因实验研究的贝叶斯模型，其中，父母、后代、两者或两者都暴露于捕食者的信号刺激下，并且在实验结束时比较不同组中后代的信息状态。模型预测，四个处理组中后代信息状态差异的模式将因实验而异，这取决于控制组提供信息的可靠性以及父母对状态价值的初始估计（父母先验）。我们认为，控制组中特定信号刺激缺失所提供信息的可靠性在不同实验中的变化可能是一种普遍现象，而贝叶斯方法可用于解释此类实验的结果。
