Angiosperm flowers have diversified in adaptation to pollinators, but are also shaped by developmental and genetic histories. The relative importance of these factors in structuring floral diversity remains unknown. We assess the effects of development, function and evolutionary history by testing competing hypotheses on floral modularity and shape evolution in Merianieae (Melastomataceae). Merianieae are characterized by different pollinator selection regimes and a developmental constraint: tubular anthers adapted to specialized buzz-pollination. Our analyses of tomography-based 3-dimensional flower models show that pollinators selected for functional modules across developmental units and that patterns of floral modularity changed during pollinator shifts. Further, we show that modularity was crucial for Merianieae to overcome the constraint of their tubular anthers through increased rates of evolution in other flower parts. We conclude that modularity may be key to the adaptive success of functionally specialized pollination systems by making flowers flexible (evolvable) for adaptation to changing selection regimes.

中文翻译：

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模块化提高了功能专门授粉系统的花卉进化速度和适应性成功率。

被子植物花在适应传粉媒介方面具有多样性，但也受到发育和遗传历史的影响。这些因素在构建花卉多样性方面的相对重要性仍然未知。我们通过测试关于 Merianieae（Melatomataceae）花模块性和形状进化的竞争假设来评估发育、功能和进化历史的影响。Merianieae 的特点是不同的传粉媒介选择机制和发育限制：管状花药适应专门的蜂鸣授粉。我们对基于断层扫描的 3 维花卉模型的分析表明，传粉者选择跨发育单位的功能模块，并且花卉模块的模式在传粉者转变期间发生变化。更远，我们表明，模块化对于 Merianieae 通过提高其他花部分的进化速率来克服管状花药的限制至关重要。我们得出的结论是，模块化可能是功能专门化授粉系统适应性成功的关键，因为它使花变得灵活（可进化）以适应不断变化的选择制度。