Global Ecology Change Research Group, University of the Sunshine Coast, Sippy Downs, Maroochydore, Australia.
Department of Aquaculture and Fish Biology, Hólar University, Hólar, Iceland.
Evolution. 2021 Aug;75(8):1953-1965. doi: 10.1111/evo.14298. Epub 2021 Jul 9.
In the evolutionary transition from solitary to group living, it should be adaptive for animals to respond to the environment and choose when to socialize to reduce conflict and maximize access to resources. Due to the associated proximate mechanisms (e.g. neural network, endocrine system), it is likely that this behavior varies between individuals according to genetic and non-genetic factors. We used long-term behavioral and genetic data from a population of eastern water dragons (Intellagama lesueurii) to explore variation in plasticity of social behavior, in response to sex ratio and density. To do so, we modeled individual variation in social reaction norms, which describe individuals' mean behavior and behavioral responses to changes in their environment, and partitioned variance into genetic and non-genetic components. We found that reaction norms were repeatable over multiple years, suggesting that individuals consistently differed in their behavioral responses to changes in the social environment. Despite high repeatability of reaction norm components, trait heritability was below our limit of detection based on power analyses (h < 0.12), leading to very little power to detect heritability of plasticity. This was in contrast to a relatively greater amount of variance associated with environmental effects. This could suggest that mechanisms such as social learning and frequency-dependence may shape variance in reaction norms, which will be testable as the dataset grows.
在从独居到群体生活的进化转变中，动物应该能够适应环境并选择何时进行社交，以减少冲突并最大限度地获取资源。由于相关的近因机制（例如神经网络、内分泌系统），这种行为可能因个体的遗传和非遗传因素而有所不同。我们使用东部水龙（Intellagama lesueurii）种群的长期行为和遗传数据，来探索对性别比例和密度变化的社交行为可塑性的变化。为此，我们构建了个体社交反应规范的变异性模型，该模型描述了个体在其环境变化时的平均行为和行为反应，并将方差划分为遗传和非遗传成分。我们发现，反应规范在多年内是可重复的，这表明个体在对社交环境变化的行为反应上始终存在差异。尽管反应规范成分具有很高的可重复性，但基于功效分析（h < 0.12），特征遗传力低于我们的检测下限，导致检测可塑性遗传力的能力非常有限。这与与环境效应相关的更大方差形成鲜明对比。这可能表明，社交学习和频率依赖性等机制可能会影响反应规范的变异性，随着数据集的增长，这将是可以验证的。
