Collaborative Research: Testing for physiological and genetic independence of rapidly evolving lifecycle components in the apple maggot, a model for seasonal adaptation

生物必须安排它们的生命周期，以避免一年中压力大的时期（例如，冬季寒冷和缺乏资源），并利用一年中天气有利、资源丰富的好时期。从植物和微生物到哺乳动物和昆虫，许多生物的休眠反应已经进化到与当地的季节条件同步。1)当代气候变化，2)人类发展和城市化导致的栖息地改变，以及3)物种通过管理或偶然引入进入新地区，这些都给生物带来了越来越多的挑战。因此，了解休眠反应是如何快速演变和补偿季节性变化的，将是理解本地和入侵物种在快速变化的世界中持续存在和传播的关键组成部分。这项研究将通过苹果蛆蝇（Rhagoletis pomonella）的休眠变化来描述允许快速适应新季节的机制。苹果蛆蝇是苹果的主要害虫，也是物种快速形成的教科书范例。在过去的200年里，pomonella已经从其原生宿主山楂（Crataegus mollis）转移到引入的驯化苹果（Malus domestica），并在此过程中在苹果上形成了新的、部分繁殖隔离的种群。在一个特定的地区，不同的植物物种之间的季节性结果时间差异很大，因此适应一种新的结果需要适应昆虫的季节性时间。在pomonella中，新衍生的苹果种群通过越冬休眠期的进化差异在其新寄主果实上建立起来，这导致昆虫生长和繁殖的时间匹配与苹果比山楂果实更早的季节有效性。进化以调整休眠时间的生理机制尚不清楚，本研究将利用果蝇种群之间的差异来量化基因和蛋白质表达的生理差异以及基因组的差异，这些差异是果蝇生命周期中关键调节性点适应的基础。此外，实验将探讨在冬眠的三个阶段（休眠诱导、休眠维持和休眠终止）中，共同的生理机制是否会潜在地限制对季节变化的进化反应的速率或方向。这项基础研究在保护生物多样性、预测农业生产和入侵物种传播等许多方面都有意义。除了识别促进对季节变化的快速反应的重要特征外，该项目还将加强进化生物学的大学预科教育计划。寄主种的形成提供了一个生态适应和新作物害虫起源的清晰直观的例子，使苍蝇成为进化的优秀大使，这是一个许多学生和公众知之甚少的主题。该研究小组此前为STEM教育开发了一个讲习班和外展计划，以提高佛罗里达州和波多黎各高中教师和学生的进化论知识，为科学课程提供材料。目前的赠款将扩大高中教师培训，增加可免费访问的网络课程材料，最重要的是，正式评估教育项目的影响。在研讨会之前、期间和之后进行的基于调查的评估将评估对进化生物学中经常被误解的概念的看法的变化。

Organisms must time their lifecycles to avoid stressful periods of the year (e.g., winter cold and lack of resources) and to exploit the good times of the year when weather is favorable and resources are abundant. Dormancy responses have evolved in many organisms, from plants and microbes to mammals and insects, to achieve synchrony with local seasonal conditions. Organisms are increasingly challenged by new seasonal regimes caused by 1) contemporary climate change, 2) habitat modifications from human development and urbanization, and 3) movement of species into new areas through managed or accidental introductions. Thus, understanding how dormancy responses rapidly evolve and compensate for shifts in seasonality will be a critical component for understanding the persistence and spread of native and invasive species in our rapidly changing world. This research will characterize the mechanisms that allow rapid adaptation to novel seasonality via changes in dormancy in the apple maggot fly, Rhagoletis pomonella, a major pest of apples and a textbook example of rapid species formation. Within the last 200 years, R. pomonella has shifted from its native host hawthorn (Crataegus mollis) to introduced, domesticated apple (Malus domestica), and in the process has formed new, partially reproductively isolated populations on apples. Seasonal fruiting time differs substantially among plant species in a given region, so adapting to a novel fruit requires adaptation in insect seasonal timing. In R. pomonella, the newly derived apple population has become established on their novel host fruit via evolved differences in timing of the overwintering dormant stage, which results in temporal matching of insect growth and reproduction with earlier seasonal availability of apple compared to hawthorn fruits. Physiological mechanisms that evolve to adjust dormancy timing are poorly understood, and this research will leverage variation among the fly populations to quantify physiological differences in gene and protein expression and differences in the genome that underlie adaptation at key regulatory points across the fly life cycle. Additionally, experiments will address whether common physiological mechanisms underlie adaptation across the three phases of dormancy (dormancy induction, maintenance, and termination) potentially constraining the rate or direction of evolutionary responses to changing seasonality. This fundamental research has implications in numerous contexts from preserving biodiversity to forecasting agricultural production and the spread of invasive species. Beyond identifying important features facilitating rapid responses to seasonal change, the project will also enhance a pre-collegiate education program in evolutionary biology. Host race formation in R. pomonella provides a clear and intuitive example of ecological adaptation and the genesis of new crop pests, making the flies excellent ambassadors for evolution, a subject poorly understood by many students and the general public. The research team previously developed a workshop and outreach program for STEM education to enhance the evolution knowledge of high school teachers and students from Florida and Puerto Rico, providing materials for science curricula. The current grant will expand the high-school teacher training, add freely accessible web-based curricular materials, and most importantly, formally evaluate the impact of the educational program. Survey-based assessments delivered before, during and after the workshop will assess changes in perception of frequently misunderstood concepts in evolutionary biology.