Department of Zoology, Stockholm University, SE-10691 Stockholm, Sweden.
Evolution. 2018 Mar;72(3):531-539. doi: 10.1111/evo.13418. Epub 2018 Jan 30.
Batesian mimicry evolution involves an initial major mutation that produces a rough resemblance to the model, followed by smaller improving changes. To examine the learning psychology of this process, we applied established ideas about mimicry in Papilio polyxenes asterius of the model Battus philenor. We performed experiments with wild birds as predators and butterfly wings as semiartificial prey. Wings of hybrids of P. p. asterius and Papilio machaon were used to approximate the first mutant, with melanism as the hypothesized first mimetic trait. Based on previous results about learning psychology and imperfect mimicry, we predicted that: melanism should have high salience (i.e., being noticeable and prominent), meaning that predators readily discriminate a melanistic mutant from appearances similar to P. machaon; the difference between the first mutant and the model should have intermediate salience to allow further improvement of mimicry; and the final difference in appearance between P. p. asterius and B. philenor should have very low salience, causing improvement to level off. Our results supported both the traditional hypothesis and all our predictions about relative salience. We conclude that there is good agreement between long-held ideas about how Batesian mimicry evolves and recent insights from learning psychology about the role of salience in mimicry evolution.
贝氏拟态进化涉及初始的主要突变，产生与模型大致相似的特征，随后是较小的改进变化。为了研究这个过程的学习心理学，我们应用了关于 Papilio polyxenes asterius 中 Battus philenor 模型的拟态的既定观念。我们进行了野外鸟类捕食者和蝴蝶翅膀作为半人工猎物的实验。使用 P. p. asterius 和 Papilio machaon 的杂交翅膀来模拟第一个突变体，假设黑变是第一个拟态特征。基于先前关于学习心理学和不完全拟态的结果，我们预测：黑变应该具有高显著性（即引人注目和突出），这意味着捕食者很容易将黑变突变体与类似于 P. machaon 的外观区分开来；第一个突变体与模型之间的差异应该具有中等显著性，以允许进一步改进拟态；而 P. p. asterius 和 B. philenor 之间最终的外观差异应该具有非常低的显著性，导致改进趋于平稳。我们的结果支持了传统假说和我们关于相对显著性的所有预测。我们得出结论，长期以来关于贝氏拟态如何进化的观点与最近关于显著性在拟态进化中的作用的学习心理学的见解之间存在很好的一致性。
