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

理解复杂器官的进化，如眼睛，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来挑战我们对自然选择进化的理解。不同物种的眼睛大小和结构差异很大，据推测，这种差异是不同生态压力的结果，例如不同环境中不同的光照水平。该项目的研究人员最近表明，特立尼达岛上一条鳉鱼的眼睛大小的进化变化与捕食有关。这一建议将建立在先前的研究基础上，以了解捕食者如何以及为什么选择眼睛大小的变化。这样的工作将增进对有利于复杂特征（如脊椎动物的眼睛）进化的条件的理解。这项研究将被纳入教育模块，并将在推广活动中展示，以进一步提高公众对自然选择进化的理解。眼睛的大小与生物体的视觉能力呈正相关。反过来，视觉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、行为和适应性之间的联系为不同的生态条件提供了原材料，从而推动了眼睛大小的进化转变。特立尼达鳉（Rivulus hartii）生活在特立尼达岛上的鱼类群落中，它们的捕食强度各不相同。捕食行为的增加与眼睛大小的遗传减小有关。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更小的眼睛。该项目将利用多方面的方法，包括在实验室和自然界中进行比较标记重获实验和扰动实验，以：(1)量化自然选择如何影响眼睛大小，(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.