Developing and testing an eco-evolutionary theory for range limits

该项目将测试生态和进化过程如何决定物种的范围边界。一个物种的地理分布是指该物种可以找到种群的地方。一个物种分布的边缘是它的地理范围边界——该物种可以在这个边界内被发现，但不能在它之外被发现。尽管所有物种都有边界，但决定它们在哪里以及如何形成的潜在机制仍然知之甚少，原因有两个。首先，一些假设的机制很难在自然环境中操纵。其次，研究人员历来从生态学或进化论的角度来处理这个问题，这两者很难融合。在这里，研究人员将使用计算模型和实验室实验相结合的方法，对在人工景观中生长的面粉甲虫进行实验，以测试决定物种地理分布因素背后的多种假设。更好地了解决定范围限制的因素对于改善入侵和濒危物种的管理以及预测物种如何改变其范围以应对气候变化至关重要。除了对紧迫的保护问题有潜在的见解外，研究人员还将通过在当地农贸市场的互动活动积极吸引公众，特别是儿童，向公众宣传生态和进化在自然种群和农业中的重要性。研究人员将使用红粉甲虫（一种常见的农业害虫Tribolium castaneum）的微观模型来控制环境条件的变化速度、扩散水平和生态竞争对手的存在。将系统地改变这些因素，以测试它们对范围极限的形成和位置的每一个直接和相互作用的影响。此外，研究人员将使用单个斑块控制来测试在其他环境条件下没有种群分散的情况下对不同环境条件的适应。将对来自微观景观和单一斑块控制的甲虫的DNA进行测序，以确定适应的基因组基础，并量化范围边缘的遗传漂变量。这些实验结果将与基因显式模拟模型相结合，以测试在中观实验中未测试的其他参数值。总体而言，该项目将提供关键数据，测试环境梯度和种间相互作用如何与扩散、适应和遗传漂变相互作用，从而影响范围限制。这些信息也可能对控制这种农业害虫物种有用。该项目将为研究生和本科生提供培训机会。该项目由人口与社区生态学、促进竞争研究的既定计划（EPSCoR）和进化过程共同资助。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The project will test how ecological and evolutionary processes determine species' range boundaries. A species' geographic distribution refers to the places where populations of that species can be found. The edge of a species' distribution is its geographic range boundary - the species can be found within this boundary, but not outside of it. Although all species have boundaries, the underlying mechanisms determining where and how they form remain poorly understood for two key reasons. First, some of the hypothesized mechanisms are difficult to manipulate in natural settings. Second, researchers have historically approached this problem from either an ecological or evolutionary perspective which can be difficult to merge. Here, the researchers will use a combination of computation models and laboratory experiments on flour beetles growing in artificial landscapes to test multiple hypotheses behind the factors that determine species' geographic distributions. A better understanding of the factors that determine range limits will be crucial for improved management of invasive and endangered species and for predicting how species will change their ranges in response to climate change. In addition to potential insights into pressing conservation concerns, the researchers will actively engage the public through interactive activities at local farmers’ markets to teach the public, particularly children, about the importance of ecology and evolution in natural populations and agriculture.The researchers will use microcosms of the red flour beetle, Tribolium castaneum, a common agricultural pest species, to manipulate the rate of change in environmental conditions, the level of dispersal, and the presence of an ecological competitor. These factors will be systematically varied to test each of their direct and interacting effects on the formation and location of range limits. Further, the researchers will use single patch controls to test for adaptation to different environmental conditions in the absence of dispersal from populations in other environmental conditions. DNA of beetles from the microcosm landscapes and the single patch controls will be sequenced to identify the genomic basis of adaptation and quantify the amount of genetic drift at the range edges. These experimental results will be combined with genetically explicit simulation models to test additional parameter values not tested in the mesocosm experiments. Overall, the project will provide critical data testing how environmental gradients and interspecific interactions interact with dispersal, adaptation, and genetic drift to affect range limits. This information may also be useful in controlling this agricultural pest species. The project will provide training opportunities for graduate and undergraduate students.This project is jointly funded by Population and Community Ecology, the Established Program to Stimulate Competitive Research (EPSCoR), and Evolutionary Processes.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.