Many sexually selected traits function as weapons, and these weapons can be incredibly diverse. However, the factors underlying weapon diversity among species remain poorly understood, and a fundamental hypothesis to explain this diversity remains untested. Although weapons can serve multiple functions, an undeniably important function is their role in fights. Thus, a crucial hypothesis is that weapon diversification is driven by the evolution of weapon modifications that provide an advantage in combat (e.g. causing more damage). Here, we test this fighting-advantage hypothesis using data from 17 species of coreid bugs. We utilize the fact that male–male combat in coreids often results in detectable damage, allowing us to link different weapon morphologies to different levels of damage among species. We find that certain weapon morphologies inflict much more damage than others, strongly supporting the fighting-advantage hypothesis. Moreover, very different weapon morphologies can inflict similarly severe amounts of damage, leading to a weapon performance landscape with multiple performance peaks. This multi-peak pattern could potentially drive different lineages towards divergent weapon forms, further increasing weapon diversity among species. Overall, our results may help explain how sexually selected weapons have evolved into the diversity of forms seen today.

中文翻译：

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武器性能推动武器进化

许多性选择特征可以作为武器，这些武器可以非常多样化。然而，物种间武器多样性的潜在因素仍然知之甚少，解释这种多样性的基本假设仍未得到检验。虽然武器可以发挥多种功能，但不可否认的重要功能是它们在战斗中的作用。因此，一个关键的假设是武器多样化是由在战斗中提供优势（例如造成更多伤害）的武器修改的演变驱动的。在这里，我们使用来自 17 种核虫的数据来测试这种战斗优势假设。我们利用 coreids 中的雄性与雄性战斗通常会导致可检测到的伤害这一事实，使我们能够将不同的武器形态与物种之间不同程度的伤害联系起来。我们发现某些武器形态造成的伤害比其他武器大得多，这有力地支持了战斗优势假设。此外，非常不同的武器形态会造成同样严重的伤害，导致武器性能出现多个性能峰值。这种多峰模式可能会推动不同的血统走向不同的武器形式，从而进一步增加物种之间的武器多样性。总体而言，我们的结果可能有助于解释性选择武器如何演变成今天所见的各种形式。这种多峰模式可能会推动不同的血统走向不同的武器形式，从而进一步增加物种之间的武器多样性。总体而言，我们的结果可能有助于解释性选择武器如何演变成今天所见的各种形式。这种多峰模式可能会推动不同的血统走向不同的武器形式，从而进一步增加物种之间的武器多样性。总体而言，我们的结果可能有助于解释性选择武器如何演变成今天所见的各种形式。