Testosterone amplifies the negative valence of an agonistic gestural display by exploiting receiver perceptual bias

Many animals communicate by performing elaborate displays that are incredibly extravagant and wildly bizarre. So, how do these displays evolve? One idea is that innate sensory biases arbitrarily favor the emergence of certain display traits over others, leading to the design of an unusual display. Here, we study how physiological factors associated with signal production influence this process, a topic that has received almost no attention. We focus on a tropical frog, whose males compete for access to females by performing an elaborate waving display. Our results show that sex hormones like testosterone regulate specific display gestures that exploit a highly conserved perceptual system, evolved originally to detect “dangerous” stimuli in the environment. Accordingly, testosterone makes certain gestures likely appear more perilous to rivals during combat. This suggests that hormone action can interact with effects of sensory bias to create an evolutionary optimum that guides how displa...

诸多动物会通过呈现精致繁复的展示行为完成交流，这类行为往往极尽奢华且怪异离奇。那么，这类展示行为究竟是如何演化而来的？现有假说之一认为，先天的感官偏好会随机偏向某些展示特征的出现，而非其他特征，最终催生了形式异乎寻常的展示行为。本研究聚焦于与信号产生相关的生理因素如何影响这一演化进程——这一议题此前几乎未受到学界关注。我们的研究对象为一种热带蛙类，其雄性个体通过呈现精致的摆臂展示行为，争夺与雌性的交配机会。研究结果显示，睾酮等性激素可调控特定的展示动作，而这些动作会利用一套高度保守的感知系统——该系统最初演化而来的功能是识别环境中的“危险”刺激源。据此而言，睾酮可让特定的展示动作在雄性争斗中，更易让竞争对手感知到威胁性。这表明，激素调控作用可与感官偏好的影响产生交互，进而形成演化最优解，以此引导展示行为的演化方向……