Modelling pollinator and nonpollinator selection on flower colour variation
Modelling pollinator and nonpollinator selection on flower colour variation
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DOI：
10.1111/1365-2745.14057
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发表时间：
2023-04
影响因子：
5.5
通讯作者：
B. Tenhumberg;A. Dellinger;Stacey D. Smith
中科院分区：
文献类型：
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作者：
B. Tenhumberg;A. Dellinger;Stacey D. Smith
花色变异在种群内部和种群之间是普遍存在的，这就是为什么它长期以来一直是自然选择研究的焦点。这项工作已经发现了广泛的选择因子，包括传粉媒介，食草动物和各种非生物因素。然而，当这些力量共同作用时，我们缺乏一个综合的框架来预测花色素沉着的表型结果。我们在这里通过一个模型提出了这样一个框架，该模型结合了营养阶段（即从生存到繁殖）和开花阶段（即吸引传粉者）对色素沉着的选择。虽然该模型同样适用于任何可以在营养组织和花中共同表达的化合物，但我们将重点放在花青素作为一类常见的色素上。我们在理论背景下和基于研究花色选择的经典系统的四种情况下探索了我们的模型的动力学。我们的模型预测，传粉媒介是花色进化的主要驱动力，但在没有花粉限制的情况下，也就是说，如果传粉媒介丰度足够高，或者传粉媒介偏好缺失或弱（颜色偏好的高方差），对幼苗存活的选择起主要作用。在每个案例研究中，我们的模型都恢复了给定选择强度和性质的每种花形态的适应性预测模式。这项工作表明，在营养阶段的选择必须单独或特别强烈地抵消传粉者对特定颜色的偏好。然而，与花青素产生相关的差异生存的影响在适应度曲线上留下了清晰的标志，这表明非传粉媒介的选择因素通常可以从经验数据中检测到。综上所述，将该模型应用于经验系统将是理解花色多样性如何演变以及预测气候和传粉者群落变化如何共同改变进化轨迹的关键。
Flower colour variation is ubiquitous within and between populations, which is why it has long been a focal point for studies of natural selection. This body of work has uncovered a wide range of selective agents, including pollinators, herbivores and various abiotic factors. Nevertheless, we lack an integrative framework for predicting the phenotypic outcome in terms of floral pigmentation when these forces act collectively and often in opposition. We here present such a framework through a model that incorporates selection on pigmentation at the vegetative phase (i.e. through survival to reproduction) and at the flowering phase (i.e. on pollinator attraction). We focus on anthocyanins as common class of pigments although the model is equally applicable to any compounds that can be jointly expressed in vegetative tissue and in flowers. We explore the dynamics of our model in a theoretical context and in four scenarios based on classic systems for studying selection on flower colour. Our model predicts that pollinators are the main driver for flower colour evolution, but selection on seedling survival plays a major role in the absence of pollen limitation, that is, if pollinator abundance is sufficiently high, or if pollinator preference is absent or weak (high variance in colour preference). In each of the case studies, our model recovered the predicted patterns of fitness for each floral morph given the strength and nature of selection. This work suggests that selection at the vegetative phase must act alone or be exceptionally strong to negate pollinator preference for particular colours. Nevertheless, the influence of differential survival associated with anthocyanin production leaves a clear signature on the fitness curves, suggesting that nonpollinator agents of selection can often be detected from empirical data. Synthesis: Overall, the application of this model to empirical systems will be key for understanding how flower colour diversity evolves and for predicting how changes in climate and pollinator communities may jointly alter evolutionary trajectories.