Frequency-dependence shapes the adaptive landscape of imperfect Batesian mimicry

Despite more than a century of biological research on the evolution and maintenance of mimetic signals, the relative frequencies of models and mimics necessary to establish and maintain Batesian mimicry in natural populations remains understudied. Here we investigate the frequency-dependent dynamics of imperfect Batesian mimicry, using predation experiments involving artificial butterfly models. We use two geographically distinct populations of Adelpha butterflies that vary in their relative frequencies of a putatively defended model (Adelpha iphiclus) and Batesian mimic (Adelpha serpa). We found that in Costa Rica, where both species share similar abundances, Batesian mimicry breaks down, and predators more readily attack artificial butterfly models of the presumed mimic, A. serpa. In contrast, in Ecuador, where A. iphiclus (model) is significantly more abundant than A. serpa (mimic), both species are equally protected from predation. Our results provide compelling experimental evidenc...

尽管学界围绕拟态信号的演化与维持已开展百余年的生物学研究，但在自然种群中建立并维持贝茨拟态（Batesian mimicry）所需的模型与拟态者的相对频率，仍未得到充分研究。本研究借助包含人工蝴蝶模型的捕食实验，探究不完全贝茨拟态的频率依赖动态。我们选取两个地理隔离的蛱蝶属（Adelpha）种群，两类种群中被推定具有防御性的模型种（Adelpha iphiclus）与贝茨拟态者（Adelpha serpa）的相对频率存在显著差异。研究发现，在两物种丰度相近的哥斯达黎加种群中，贝茨拟态失效，捕食者更易攻击被认定为拟态者的A. serpa人工蝴蝶模型。与之相对，在模型种A. iphiclus丰度显著高于拟态者A. serpa的厄瓜多尔种群中，两个物种均能获得同等程度的捕食防护。本研究结果提供了极具说服力的实验证据……