DISSERTATION RESEARCH: The evolution of complexity: tests of the ecological drivers of eye size evolution in Trinidadian killifish (Rivulus hartii)

了解复杂器官（如眼睛）的进化是进化生物学的一个长期目标。眼睛的复杂结构经常被作为一个例子，挑战我们对自然选择进化的理解。眼睛的大小和结构在不同的物种之间有很大的差异，有人假设这种差异是对比生态压力的结果，例如不同环境中的不同光照水平。该项目的研究人员最近表明，捕食与特立尼达岛上鳉鱼眼睛大小的进化变化有关。这项建议将建立在以前的研究基础上，以了解捕食者如何以及为什么选择眼睛大小的变化。这些工作将增进对有利于复杂特征（如脊椎动物眼睛）进化的条件的理解。这项研究将被纳入教育单元，在外联活动中介绍，以进一步提高公众对自然选择进化的理解。眼睛的大小与有机体的视觉能力呈正相关。反过来，视力与直接或间接影响健康的行为密切相关。眼睛大小的变化与视觉能力、行为和健康之间的这种联系为不同的生态条件提供了原材料，以推动眼睛大小的进化变化。特立尼达鳉（Rivulus hartii）在特立尼达岛的鱼类群落中发现，捕食强度各不相同。增加的捕食与眼睛大小的遗传性下降有关。这项工作在生态选择力和眼睛大小的进化变化之间建立了明确的联系，但它没有建立因果关系，也没有解释为什么捕食者选择较小的眼睛大小。该项目将利用多方面的方法，包括在实验室和自然中进行比较标记重捕获实验和扰动实验，以：（1）量化自然界中选择如何对眼睛大小起作用，以及（2）实验测试捕食者对眼睛大小进化的影响。

Understanding the evolution of complex organs, such as the eye, is a long-standing goal in evolutionary biology. The intricate structure of the eye is frequently presented as an example that challenges our understanding of evolution by natural selection. Eye size and structure vary tremendously across species and it has been hypothesized that this variation is the result of contrasting ecological pressures, such as differing light levels in different environments. This project's researchers recently showed that predation is associated with evolutionary changes in in the eye size of a killifish on the island of Trinidad. This proposal will build upon this previous research to understand how and why predators select for shifts in eye size. Such work will enhance comprehension of the conditions that favor the evolution of complex traits such as the vertebrate eye. This research will be incorporated into educational modules that will be presented at outreach events to further enhance the public's understanding of evolution by natural selection.Eye size is positively correlated with the visual capacity of an organism. In turn, vision is closely linked to behaviors that directly and indirectly influence fitness. This connection between variation in eye size and visual aptitude, behavior, and fitness provides the raw materials for divergent ecological conditions to drive evolutionary shifts in eye size. Trinidadian killifish (Rivulus hartii) are found in fish communities on the island of Trinidad that vary in predation intensity. Increased predation is associated with genetically based declines in eye size. This work established a clear link between an ecological selective force and evolutionary shifts in eye size, but it does not establish causation, nor does it explain why predators select for a smaller eye size. This project will leverage a multifaceted approach that includes comparative mark recapture experiments and perturbation experiments in the lab and nature to: (1) quantify how selection operates on eye size in nature, and (2) experimentally test the influence of predators on eye size evolution.