Department of Ecology and Evolutionary Biology (EEB), University of Colorado Boulder, Boulder, CO, USA.
Mara Hyena Project, Karen, Nairobi, Kenya.
Biol Lett. 2022 Jul;18(7):20220194. doi: 10.1098/rsbl.2022.0194. Epub 2022 Jul 20.
In ecology and evolutionary biology (EEB), the study of developmental plasticity seeks to understand ontogenetic processes underlying the phenotypes upon which natural selection acts. A central challenge to this inquiry is ascertaining a causal effect of the exposure on the manifestation of later-life phenotype due to the time elapsed between the two events. The exposure is a potential cause of the outcome-i.e. an environmental stimulus or experience. The later phenotype might be a behaviour, physiological condition, morphology or life-history trait. The latency period between the exposure and outcome complicates causal inference due to the inevitable occurrence of additional events that may affect the relationship of interest. Here, we describe six distinct but non-mutually exclusive conceptual models from the field of lifecourse epidemiology and discuss their applications to EEB research. The models include Critical Period with No Later Modifiers, Critical Period with Later Modifiers, Accumulation of Risk with Independent Risk Exposures, Accumulation of Risk with Risk Clustering, Accumulation of Risk with Chains of Risk and Accumulation of Risk with Trigger Effect. These models, which have been widely used to test causal hypotheses regarding the early origins of adult-onset disease in humans, are directly relevant to research on developmental plasticity in EEB.
在生态学和进化生物学（EEB）中，发育可塑性的研究旨在理解自然选择作用于表型的个体发育过程。这一探究的核心挑战是由于两个事件之间存在时间间隔，确定暴露对后期表型表现的因果效应。暴露是结果的潜在原因，即环境刺激或经验。后期表型可能是行为、生理状况、形态或生活史特征。由于可能发生其他事件会影响感兴趣的关系，因此暴露和结果之间的潜伏期使因果推理变得复杂。在这里，我们描述了来自生命历程流行病学领域的六个不同但非互斥的概念模型，并讨论了它们在 EEB 研究中的应用。这些模型包括无后期修饰的关键期、有后期修饰的关键期、具有独立风险暴露的风险积累、具有风险聚类的风险积累、具有风险链的风险积累和具有触发效应的风险积累。这些模型已广泛用于测试关于人类成年发病的早期起源的因果假设，与 EEB 中发育可塑性的研究直接相关。
