Diversity in Müllerian mimicry: the optimal predator sampling strategy explains both local and regional polymorphism in prey

The convergent evolution of warning signals in unpalatable species, known as Müllerian mimicry, has been observed in a wide variety of taxonomic groups. This form of mimicry is generally thought to have arisen as a consequence of local frequency-dependent selection imposed by sampling predators. However, despite clear evidence for local selection against rare warning signals, there appears an almost embarrassing amount of polymorphism in natural warning colors, both within and among populations. Because the model of predator cognition widely invoked to explain Müllerian mimicry (Müller’s “fixed nk” model) is highly simplified and has not been empirically supported; here, we explore the dynamical consequences of the optimal strategy for sampling unfamiliar prey. This strategy, based on a classical exploration–exploitation trade-off, not only allows for a variable number of prey sampled, but also accounts for predator neophobia under some conditions. In contrast to Müller’s “fixed nk” sampli...

不可食物种中警戒信号的趋同演化（即缪勒拟态，Müllerian mimicry）已在多种分类群中被观察到。这种拟态形式通常被认为是由取样捕食者施加的局部频率依赖选择所导致的。然而，尽管有明确证据表明局部选择会对抗罕见的警戒信号，但自然警戒色在种群内部和种群之间都存在令人费解的大量多态性。由于被广泛用于解释缪勒拟态的捕食者认知模型（即缪勒的“固定nk模型”，Müller’s “fixed nk” model）高度简化且缺乏实证支持；因此，我们在此探究对陌生猎物取样的最优策略所产生的动态结果。与缪勒的“固定nk”取样...