Hotspots of Genome Evolution in a Rapid Vertebrate Radiation

进化辐射是指以极高的速度产生新物种的生物体群。生物学家长期以来一直使用这种辐射作为模型系统来研究物种形成的过程。过去的研究通常集中在可能促进新物种形成的生物特征或其栖息地上。然而，随着基因组测序方法的发展，现在有可能确定可能参与产生进化辐射的特定基因。该项目旨在确定可能与北美、中美和南美一组小型彩色鸣禽的异常多样化有关的基因。该项目提供了一个丰富的机会来了解进化辐射的遗传基础和产生最多样化的脊椎动物物种群体之一的基质。该项目将包括对本科生和研究生的培训和指导，以及将研究扩展到更广泛的社区的外展计划。该研究项目的重点是林莺（林莺科），这是一个有100多个物种的鸟类家族，在过去的1000万年里发生了多样化，是所有鸣禽中进化速度最快的鸟类之一。该项目的目标是研究可能参与这一群体多样化的基因的进化史。一个重要的起点需要对潜在的候选基因有一定的了解，而这在几乎所有非模式生物系统中都是缺乏的。然而，在莺中，先前对独立杂交区的研究已经产生了一组与物种差异相关的候选基因组区域，其中许多已被发现与羽毛色素沉着有关。该项目利用系统发育比较方法的工具和理论框架，并将分析辐射中每个物种的多个个体的全基因组序列数据。这项工作将首先量化密切相关物种之间的基因组分化模式，以确定与特殊谱系特异性进化相关的染色体区域和基因。其次，研究人员将估计辐射中物种基因组中采样的树木拓扑结构的谱系不一致性，以测试网状进化的证据。最后，通过利用鸟类生命树中广泛可用的基因组，该项目将扩展到莺之外，以解决一个关于进化辐射中非同寻常的物种形成的基本问题：是否存在多样化的基因组预测因子？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。

Evolutionary radiations are groups of organisms that produce new species at an exceptionally high rate. Biologists have long used such radiations as model systems to study the process of speciation. Past studies have commonly focused on the traits of organisms or their habitats that might have facilitated the formation of new species. With the development of genome sequencing methods, however, it is now possible to identify specific genes that might be involved in producing evolutionary radiations. This project aims to identify genes that may be associated with the exceptional diversification of a group of small, colorful songbirds in North, Central, and South America. The project offers a rich opportunity to understand the genetic bases of evolutionary radiations and the substrate that has given rise to one of the most diverse vertebrate species groups. The project will include training and mentorship of undergraduate and graduate students, as well as outreach programs to extend the research to the broader community.The research project focuses on wood warblers (Parulidae), a family of birds with over 100 species that diversified within the last 10 million years, and which has one of the fastest evolutionary rates across songbirds. The goal of the project is to study the evolutionary history of genes potentially involved in the diversification of this group. An important starting point requires some knowledge of potential candidate genes involved, something lacking in nearly all non-model biological systems. In warblers, however, previous studies of independent hybrid zones have generated a set of candidate genomic regions associated with species differences, many of which have been found to be involved in plumage pigmentation. The project draws upon the tools and theoretical framework of phylogenetic comparative methods and will analyze whole genome sequence data from multiple individuals of every species in the radiation. The work will first quantify patterns of genomic divergence among closely related species to identify chromosomal regions and genes associated with exceptional lineage-specific evolution. Second, the researchers will estimate genealogical discordance in the topologies of trees sampled across the genomes of species in the radiation to test for evidence of reticulate evolution. Finally, by making use of the widespread availability of genomes across the avian tree of life, the project will extend beyond warblers to address a fundamental question regarding the extraordinary speciation within evolutionary radiations: are there genomic predictors of diversification?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.