Plasticity of behavioural variability reflects conflicting selection in group-living and solitary desert locusts
Plasticity of behavioural variability reflects conflicting selection in group-living and solitary desert locusts
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行为变异的可塑性反映了群居和独居沙漠蝗虫的冲突选择
DOI：
10.1101/2020.03.18.996983
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
Cooper B
中科院分区：
文献类型：
--
作者：
Cooper B
群居动物往往比单独生活的动物表现出更少的行为变化。人们普遍认为，这种差异至少在一定程度上反映了对不同选择压力的适应性反应：群体生活应该倾向于更统一的行为进化，而独居应该倾向于更不可预测的行为。然而，将这些截然不同的选择压力与行为可变性的内在差异联系起来的经验证据在很大程度上是缺乏的。沙漠蝗虫（Schistocerca gregaria）表现为两种截然不同的生态表型，一种是独居的隐蔽“独居期”，另一种是聚集成非常大而密集的群体的群居“群居期”。这种“相位多表型”的进化是为了应对变化迅速且不可预测的对比选择压力。平均行为的相位差被很好地描述了，但以前没有研究考虑过变异性的差异。在这里，我们使用蝗虫阶段多表型来检验群体生活导致行为内在变异性减少的假设。我们测量了两种表型中的两种行为：同种动物存在时的运动活动，以及单独接近食物时的运动犹豫。我们反复分析了每个个体，并在对数-正态混合效应模型中估计了相对于均值的可变性，该模型明确解释了行为测量中的均值-方差依赖性。我们的研究结果表明，两个阶段之间的相对行为变异性是不同的，这与生态学理论的预测一致：在群体生活的群居表型中，个体内部和个体之间的变异性都较低。这与之前对蜘蛛和蟋蟀的社会生态位构建的研究形成对比，并突出了社会生态学的重要性：在形成非社会集体的动物中，如蝗虫，减少个体行为的可变性是一致集体行为的关键。当群居蝗虫被单独测试和独居蝗虫被成群测试时，变异性的差异仍然存在，这表明它们不仅仅是对不同社会环境的灵活反应，而是每个阶段的个体动物固有的。蝗虫的这种“变异多表型”提供了经验证据，表明对群体生活的进化适应推动了个体内部和个体之间行为变异性的减少。
Animals living in groups tend to express less variable behaviour than animals living alone. It is widely assumed that this difference reflects, at least in part, an adaptive response to contrasting selection pressures: group-living should favour the evolution of more uniform behaviour whereas lone-living should favour behaviour that is less predictable. Empirical evidence linking these contrasting selection pressures to intrinsic differences in behavioural variability is, however, largely lacking. The desert locust, Schistocerca gregaria, manifests in two very distinct eco-phenotypes, a lone-living cryptic “solitarious phase” and a swarming “gregarious phase” that aggregates into very large and dense groups. This “phase polyphenism” has evolved in response to contrasting selection pressures that change rapidly and unpredictably. Phase differences in mean behaviour are well-characterised, but no previous study has considered differences in variability. Here we used locust phase polyphenism to test the hypothesis that group living leads to the evolution of reduced intrinsic variability in behaviour. We measured two behaviours in both phenotypes: locomotor activity in the presence of conspecifics, and locomotor hesitation in approaching food when alone. We assayed each individual repeatedly and estimated variability relative to the mean in log-normal mixed-effects models that explicitly account for the means-variance dependency in the behavioural measures. Our results demonstrate that relative behavioural variability differs between the two phases in line with predictions from ecological theory: both within-individual and between-individual variability were lower in the group-living gregarious phenotype. This contrasts with previous studies on social niche construction in spiders and crickets, and highlights the importance of social ecology: in animals that form non-social collectives, such as locusts, reduced individual behavioural variability is key for coherent collective behaviour. The differences in variability persisted when gregarious locusts were tested in isolation and solitarious locusts were tested in groups, indicating that they arise not simply as flexible reactions to different social contexts, but are intrinsic to the individual animals of each phase. This “variance polyphenism” in locusts provides empirical evidence that evolutionary adaptation for group living has driven a reduction in within- and between-individual behavioural variability.
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影响因子：
2.7
作者：
HUMPHRIE.DA;DRIVER, PM
通讯作者：
DRIVER, PM
影响因子：
2.4
作者：
Jones, Katherine A.;Jackson, Andrew L.;Ruxton, Graeme D.
通讯作者：
Ruxton, Graeme D.
影响因子：
4.8
作者：
Urszan, Tamas Janos;Zsolt Garamszegi, Laszlo;Herczeg, Gabor
通讯作者：
Herczeg, Gabor
社交松鸦的个性一致性而非社交利基专业化的证据
DOI：
--
发表时间：
2018
期刊：
影响因子：
--
作者：
Kelsey B. McCune;P. Jablonski;Sang;R. Ha
通讯作者：
R. Ha
影响因子：
5.8
作者：
Carpenter, Bob;Gelman, Andrew;Riddell, Allen
通讯作者：
Riddell, Allen