How do density dependent dynamics influence the efficacy of mimetic signaling?

模仿是进化适应的一个经典例子，生物体通过与不同物种相似而获得选择性利益。在贝叶斯模仿的例子中，美味的模仿者通过向潜在的捕食者吸收不美味的模型的信号来获得保护。进化论预言，任何能提高模型和模仿者之间相似性的突变都应该受到自然选择的青睐。因此，模仿型多态性的普遍存在、模仿型完美性的显著差异以及明显静态的不完美模仿型信号的存在令人费解。尽管人们提出了许多假说来解释这些令人困惑的现象，但该领域最近的研究表明，任何降低捕食者预测哪些潜在猎物有毒的能力的因素，都会导致不完美的模仿者的选择压力减轻。在这里，研究人员测试了密度依赖效应，单独或与频率依赖效应一起，增加捕食者的不确定性，并导致对不完美模仿特征的放松选择的假设。研究人员还将与K-12 STEM教师合作，改善与公立学校的联系。虽然频率依赖动力学的重要性在模仿文献中得到了很好的确立，但它们与不完全模仿的进化和模仿多态性的悖论之间的关系仍然存在问题。至少从两个原因来看，找到密度依赖效应的证据是非常重要的。首先，它将提高对控制捕食者行为因素的理解。这很重要，因为捕食者群落可能在空间和时间尺度上都有很大的变化。因此，了解猎物密度和丰度的变化如何影响捕食者的学习，对于预测不完美模仿持续存在的条件至关重要。其次，密度效应为多态模仿的维持提供了一个直观的假设，因为在一个给定的捕食者群落中，多个不适宜的模型的绝对或相对密度的空间和/或时间变化预计会为适宜的模仿者产生一个异质的适合度景观，这可能导致多态形式的起源或进一步分化。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Mimicry is a classic example of evolutionary adaptation where organisms gain a selective benefit by resembling a different species. In cases of Batesian mimicry, palatable mimics gain protection from predation by co-opting an unpalatable model’s signal to potential predators. Evolutionary theory predicts that any mutation that improves the resemblance between the model and mimic should be favored by natural selection. Therefore, the widespread occurrence of mimetic polymorphism, the conspicuous variance in mimetic perfection, and the existence of apparently static imperfect mimetic signals is puzzling. Although numerous hypotheses have been proposed to explain these puzzling phenomena, recent research in this field suggests that any factor that reduces a predator’s ability to predict which potential prey items are toxic will lead to relaxed selective pressure on imperfect mimics. Here, the researchers test the hypothesis that density dependent effects, alone or in concert with frequency-dependent effects, increase predator uncertainty and cause relaxed selection on imperfect mimetic traits. Researchers will also partner with K-12 STEM teachers to improve outreach to public schools.Although the importance of frequency-dependent dynamics is well established in the mimicry literature, questions remain about their relationship to the evolution of imperfect mimicry and the paradox of mimetic polymorphism. Finding evidence of density dependent effects would be significant for at least two reasons. First, it would improve understanding of the factors governing predator behavior. This is important because predator communities likely vary significantly across both spatial and temporal scales. Therefore, understanding how variation in prey density and abundance influences predator learning is crucial to predicting the conditions under which imperfect mimicry is expected to persist. Second, density effects provide an intuitive hypothesis for the maintenance of polymorphic mimicry because spatial and/or temporal variance in the absolute or relative density of multiple, unpalatable models within a given predator community is expected to generate a heterogeneous fitness landscape for palatable mimics that could lead to the origin of, or further divergence between, polymorphic forms.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.