NSFDEB-NERC: Interspecific interference, character displacement and range expansion

为什么有些物种分布如此广泛，而另一些物种则局限于小区域？负面的相互作用，如与近亲物种的攻击，可能会阻止一个物种扩大其范围。如果是这样的话，使一个物种能够避免负面相互作用的特征应该与范围扩大有关。这一预测将首次得到验证，实验对象是一种分布广泛的蜻蜓，这种蜻蜓的翅膀颜色变化非常大，以至于一度被认为是多种多样的。与浅色翅膀的个体相比，深色翅膀的个体受到近亲物种的干扰程度要低得多。这个系统提供了一个无与伦比的机会来推进物种之间的负相互作用如何影响物种分布的理解。随着物种的活动范围因气候变化而发生变化，一些物种将与它们以前从未遇到过的近亲相互作用。这个项目的结果可以帮助预测这些相互作用的结果，从而预测未来的物种分布。该项目包括与英国和拉丁美洲的研究人员合作，并将为学生提供实地、实验室和计算研究培训。将启动一个现有的公民科学计划的西班牙语版本，以扩大与公众的接触。基于十多年来对红斑豆娘（Hetaerina spp.）繁殖和侵略性干扰的进化原因和后果的研究，该项目解决了减少种间干扰的适应如何影响范围扩大的问题。焦点物种，H. titia，翅膀的颜色随季节和地理而变化。为了理解为什么这个物种的翅膀颜色会随季节变化，将进行一系列的实地实验，以区分不同的进化权衡假设。为了区分季节颜色变化的起源和消失的不同情况，将使用全基因组数据重建整个物种范围内种群之间的系统发育关系。为了进一步阐明季节性颜色变化是如何进化的，多元系统发育性状进化模型将适用于广泛的表型数据集。最后，为了验证范围扩展的预测，将使用聚结模型来比较红杉种群之间以及红杉与四个同系物之间的多样化率和历史人口统计学。该项目还将产生第一个广泛的种内多表型进化系统发育分析，并为红斑豆娘提供新的基因组资源。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。

Why are some species so widespread while others are restricted to small areas? Negative interactions, such as aggression, with closely-related species could prevent a species from expanding its range. If so, traits that enable a species to avoid negative interactions should be associated with range expansion. This prediction will be tested, for the first time, using a widespread species of dragonfly that shows extraordinary variation in wing coloration – so much so that it was once thought to be multiple species. Dark-winged individuals experience much lower levels of interference from closely-related species than do light-winged individuals. This system provides an unparalleled opportunity to advance understanding of how negative interactions between species affect species distributions. As species’ ranges shift in response to climate change, some species will interact with close relatives that they have not encountered previously. The results of this project could help predict the outcome of those interactions and, therefore, species distributions in the future. The project includes collaborations with researchers in the U.K. and Latin America and will provide field, lab and computational research training for students. A Spanish-language version of an existing citizen science initiative will be launched to expand engagement with the public.Building on well over a decade of research on the evolutionary causes and consequences of reproductive and aggressive interference in rubyspot damselflies (Hetaerina spp.), this project tackles the question of how adaptations that reduce interspecific interference affect range expansion. The focal species, H. titia, varies in wing coloration both seasonally and geographically. To understand why this species’ wing coloration changes seasonally, a series of field experiments will be carried out to distinguish among alternative evolutionary trade-off hypotheses. To distinguish among alternative scenarios for the origin and loss of the seasonal color change, phylogenetic relationships among populations throughout the species’ range will be reconstructed using whole-genome data. To further clarify how the seasonal color change evolved, multivariate phylogenetic trait evolution models will be fit to a range-wide phenotypic dataset. Finally, to test the range expansion prediction, coalescence models will be used to compare rates of diversification and historical demography among H. titia populations and between H. titia and four congeners. This project will also produce the first range-wide intraspecific phylogenetic analysis of the evolution of a polyphenic trait, and new genomic resources for rubyspot damselflies.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.