Abstract

The possibility that sexual selection promotes adaptive evolution in variable environments remains controversial. In particular, where the scale of environmental variation results in parents and their offspring experiencing different environmental conditions, such variation is expected to break down associations between adult sexual traits and adaptive offspring traits. However, when adaptive offspring plasticity in nonsexual traits acts as an indirect benefit of mate choice, then mate choice for males that produce more plastic offspring could promote adaptation to variable environments. This hypothesis assumes that male sexual signals predict offspring plasticity, which has rarely been tested. To test this assumption, we used spadefoot toads (Spea multiplicata) to investigate whether variation in male sexual signals predicts the expression of tadpole tail-fin plasticity in response to predation cues. Such plasticity has been shown to be adaptive in numerous amphibian taxa. We found that condition-dependent male call characteristics predicted offspring plasticity. Generally, both phenotypic plasticity and female mate choice are ubiquitous in nature; therefore, adaptive associations between male sexual signals and offspring plasticity such as the one reported here might be common.

Significance statement

Sexual signals can indicate individuals’ capacity to sire high-quality offspring, which provides a mechanism by which sexual selection can contribute to adaptive evolution. Whether this occurs in variable environments is unclear, however, because variable environments can expose parents and their offspring to different selection pressures. To address this uncertainty, we investigated the possibility that sexual signals can signal the capacity to sire offspring that express adaptive phenotypic plasticity in response to prevailing selective pressures. Using spadefoot toads, we found that condition-dependent male sexual signals predict the expression of tadpole tail-fin plasticity in response to predation cues. Because this form of plasticity has been demonstrated to be adaptive in several amphibian taxa, our results suggest that associations between sexual signals and adaptive offspring plasticity can allow sexual selection to promote adaptive evolution in variable environments.

中文翻译：

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条件依赖的男性性信号预测后代适应性捕食者诱导的可塑性

摘要

性选择在可变环境中促进适应性进化的可能性仍然存在争议。特别是，当环境变化的程度导致父母及其后代经历不同的环境条件时，这种变化有望破坏成年性性状与适应性后代性状之间的联系。但是，当非性状中的适应性后代可塑性作为配偶选择的间接利益时，那么产生更多可塑性后代的雄性的配偶选择会促进对可变环境的适应。该假设假设男性性信号可预测后代的可塑性，而这一点很少得到检验。为了验证这一假设，我们使用了赤脚蟾蜍（Spea multiplicata），以调查男性性信号的变化是否可以预测对捕食线索做出反应的of尾鳍可塑性的表达。这种可塑性已被证明可适应许多两栖类群。我们发现条件依赖的雄性召唤特征预测后代可塑性。通常，表型可塑性和雌性配偶的选择在自然界都是普遍存在的。因此，男性性信号与后代可塑性之间的适应性关联（如此处报道的关联）可能很常见。

重要性声明

性信号可以表明个体拥有高品质后代的能力，这提供了一种机制，通过这种机制，性选择可以促进适应性进化。但是，尚不清楚这是否在可变环境中发生，因为可变环境会使父母及其后代承受不同的选择压力。为了解决这种不确定性，我们研究了性信号可能会发出信号来表达对适应性选择压力作出反应而表现出适应性表型可塑性的后代的能力。使用黑脚蟾蜍，我们发现条件依赖性的男性性信号可预测捕食线索对of尾鳍可塑性的表达。由于这种可塑性在多种两栖类动物中都具有适应性，