Joint Evolution of Behavioral and Morphological Plasticity in Multiple Predation Regimes

捕食者-猎物相互作用在生态学和进化中起着核心作用。这一建议在两个重要方面扩展了对捕食者-猎物相互作用的现有理解：1)大多数关于猎物对捕食者反应的研究集中在几种类型的猎物反应中的一种-例如，反捕食者行为，或对捕食者的形态防御，或化学防御。然而，猎物通常表现出一套潜在的相互依赖的反捕食者反应。例如，在形态上防御良好的猎物（例如，有厚壳或刺的猎物）可能对捕食者表现出相对较小的行为反应，而在形态上脆弱的猎物可能表现出强烈的躲避捕食者的倾向。也就是说，最佳的猎物行为可能取决于猎物的形态，而无效的猎物形态的代价可以通过补偿行为来调节。令人惊讶的是，很少有实验涉及多个猎物对捕食者的反应的联合进化。2)同样，大多数关于捕食者对猎物影响的实验研究都是考察一个捕食者对猎物的影响。然而，在自然界中，大多数猎物都面临着多个捕食者。对一个掠食者的适当反应实际上可能会增加另一个掠食者的风险。令人惊讶的是，人们对猎物如何平衡多个捕食者产生的相互冲突的选择压力知之甚少。这一建议将讨论对多种捕食者的行为和形态反应的联合进化。焦点猎物（一种常见的，数量众多的蜗牛）是本研究的模式生物，因为：1)已知它不仅对捕食者表现出行为和形态反应，而且对来自两种捕食者的化学信号也表现出反应，2)它可以在实验室中迅速大量饲养。

9618702 SIH Predator-prey interactions play a central role in ecology and evolution. This proposal extends the existing understanding of predator-prey interactions in two important ways: 1) Most studies of prey responses to predators focus on one of several types of prey responses - e.g., antipredator behavior, or morphological defenses against predators, or chemical defenses. Prey, however, often show a suite of potentially inter-dependent antipredator responses. For example, prey that are well defended morphologically (e.g., that have a thick shell or spines) might show relatively little behavioral response to predators, while prey that are morphologically vulnerable might show a strong tendency to hide from predators. That is, the optimal prey behavior might depend on prey morphology and the cost of having an ineffective prey morphology can be mediated by compensatory behavior. Surprisingly few experiments have addressed the joint evolution of multiple prey responses to predators. 2) Similarly, most experimental studies of predator impacts on prey examine the effects of one predator on prey. In nature, however, most prey face multiple predators. The appropriate response to one predator might actually increase risk from another predator. Surprisingly little is known about how prey balance the conflicting selection pressures generated by multiple predators. This proposal will address the joint evolution of behavioral and morphological responses to multiple predators. The focal prey (a common, abundant snail) is a model organism for this study because: 1) it is known to show both behavioral and morphological responses to not just the predators, but also to chemical cues from both predators, and 2) it can be reared rapidly in huge numbers in the laboratory.