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

生物体必须对其生命周期进行计时，以避免一年中的紧张时期(例如，冬季寒冷和资源匮乏)，并利用一年中气候有利、资源丰富的好时机。从植物和微生物到哺乳动物和昆虫，许多生物体的休眠反应已经进化，以实现与当地季节条件的同步。由于1)当代气候变化，2)人类发展和城市化对栖息地的改变，以及3)物种通过有管理的或偶然的引入进入新的区域，生物受到新的季节性制度的日益挑战。因此，了解休眠反应如何快速演变并补偿季节性的变化，将是理解本地物种和入侵物种在我们快速变化的世界中的持久性和传播的关键组成部分。这项研究将描述通过改变苹果蝇的休眠状态来快速适应新的季节性的机制，它是苹果的主要害虫，也是快速物种形成的教科书例子。在过去的200年里，波蒙氏菌从其原生宿主山楂(Crataegus Mollis)转移到引进驯化的苹果(Malus Home Tica)，并在此过程中形成了新的、部分繁殖隔离的苹果种群。在一个特定的地区，不同植物的季节性结实时间有很大的不同，因此适应一种新的水果需要适应昆虫的季节性时间。在Pomonella中，新派生的苹果种群是通过越冬休眠期的进化差异建立在其新的寄主果实上的，这导致昆虫的生长和繁殖与苹果的季节性供应比山楂果实更早的季节性匹配。进化来调整休眠时间的生理机制尚不清楚，这项研究将利用苍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中的差异，这些差异是苍蝇生命周期中关键调节点适应的基础。此外，实验将探讨在休眠的三个阶段(休眠诱导、维持和终止)是否存在共同的生理机制，潜在地限制进化对季节性变化的反应的速度或方向。从保护生物多样性到预测农业生产和入侵物种的传播，这项基础性研究具有多方面的影响。除了确定有助于对季节变化做出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前教育计划。Pomonella寄主小种的形成为生态适应和新的作物害虫的发生提供了一个明确而直观的例子，使苍蝇成为进化的优秀大使，而这是一个许多学生和普通公众很难理解的主题。研究团队此前为STEM教育开发了一个研讨会和推广计划，以增强来自佛罗里达和波多黎各的高中教师和学生的进化知识，为科学课程提供材料。目前的拨款将扩大高中教师培训，增加免费获取的网络课程材料，最重要的是，正式评估教育计划的影响。在研讨会之前、期间和之后提供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.