Summary Plant chemodiversity, the diversity of plant‐specialized metabolites, is an important dimension of biodiversity. However, there are so far few mathematical models to test verbal hypotheses on how chemodiversity evolved. Here, we develop such a model to test predictions of five hypotheses: the ‘fluctuating selection hypothesis’, the ‘dominance reversal hypothesis’, the interaction diversity hypothesis, the synergy hypothesis, and the screening hypothesis. We build a population genetic model of a plant population attacked by herbivore species whose occurrence fluctuates over time. We study the model using mathematical analysis and individual‐based simulations. As predicted by the ‘dominance reversal hypothesis’, chemodiversity can be maintained if alleles conferring a defense metabolite are dominant with respect to the benefits, but recessive with respect to costs. However, even smaller changes in dominance can maintain polymorphism. Moreover, our results underpin and elaborate predictions of the synergy and interaction diversity hypotheses, and, to the extent that our model can address it, the screening hypotheses. By contrast, we found only partial support for the ‘fluctuating selection hypothesis’. In summary, we have developed a flexible model and tested various verbal models for the evolution of chemodiversity. Next, more mechanistic models are needed that explicitly consider the organization of metabolic pathways.

中文翻译：

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植物化学多样性是如何进化的？在一个群体遗传模型中检验五个假设


摘要 植物化学多样性，即植物特有代谢物的多样性，是生物多样性的一个重要方面。然而，迄今为止，很少有数学模型可以测试有关化学多样性如何进化的口头假设。在这里，我们开发了这样一个模型来测试五个假设的预测：“波动选择假说”、“优势反转假说”、相互作用多样性假说、协同假说和筛选假说。我们建立了一个植物种群的种群遗传模型，该模型受到食草动物物种的攻击，其发生率随着时间的推移而波动。我们使用数学分析和基于个体的模拟来研究该模型。正如“显性逆转假说”所预测的那样，如果赋予防御代谢物的等位基因在收益方面占主导地位，但在成本方面呈隐性，则可以维持化学多样性。然而，即使是更小的优势变化也可以维持多态性。此外，我们的结果支持并详细预测了协同作用和相互作用多样性假设，并且在我们的模型可以解决它的范围内，筛选假设。相比之下，我们只发现部分支持“波动选择假说”。总之，我们开发了一个灵活的模型，并测试了化学多样性进化的各种语言模型。接下来，需要更多的机械模型来明确考虑代谢途径的组织。