The evolution of feeding tolerance for chemically-rich seaweeds among herbivore populations: a tropical-temperate contrast

过去25年的研究海藻草食动物的相互作用已经见证了显着的进步，我们的理解海藻防御，化学和形态机制，海藻用来保护自己免受草食动物的消耗。相比之下，我们有相对较少的信息，近端和最终的机制塑造草食动物的摄食偏好和耐海藻防御的演变。例如，有大量证据表明热带海藻比温带海藻产生更多类型和数量的海藻化学防御。相比之下，几乎没有直接的证据表明，热带食草动物是否进化出更大的喂养偏好，和青少年的表现，热带海藻相对于温带食草动物。使用跨学科的方法，包括现场采样，基于实验室的摄食行为测定，幼鱼性能测定，生化操作和DNA测序，研究人员将直接比较热带和温带种群对富含化学物质的热带海藻的遗传摄食反应。这些实验将引导研究者辨别热带海藻和食草动物是否以扩散的共同进化方式进化。 研究人员还将进行选择实验，以评估对富含化学物质的海藻的摄食耐受性是否会以能量为代价。 更广泛的影响包括与查尔斯顿学院的项目和NSF资助的本科生研究经验项目合作，以便在三年内培训至少10-15名本科生。 研究生也将在项目期间接受培训。

The past 25 years of research on seaweed-herbivore interactions have witnessed remarkable advances in our understanding of seaweed defenses, the chemical and morphological mechanisms that seaweeds use to protect themselves from being consumed by their herbivores. In contrast, we have relatively less information on the proximate and ultimate mechanisms sculpting the evolution of herbivore feeding preference and tolerance for seaweed defenses. As an example, there is a mountain of evidence that tropical seaweeds produce greater types and quantities of seaweed chemical defenses than temperate seaweeds. In contrast, there is little direct evidence on whether tropical herbivores have evolved greater feeding preferences for, and juvenile performance on, tropical seaweeds relative to temperate herbivores. Using a cross- disciplinary approach that includes field-sampling, laboratory-based feeding behavior assays, juvenile performance assays, biochemical manipulation and DNA sequencing, the investigator will directly compare the genetically based feeding responses of tropical and temperate populations toward chemically-rich tropical seaweeds. These experiments should lead the investigator to discern whether or not tropical seaweeds and herbivores are evolving in a diffuse co-evolutionary manner. The investigator will also perform selection experiments to assess whether evolving feeding tolerance for a chemically-rich seaweed comes at an energetic cost. The broader impacts include partnering with programs at College of Charleston and an NSF-funded Research Experience for Undergraduates program in order to train at least 10-15 undergraduates across three years. Graduate students will also be trained during the course of the project.