RAPID PHENOTYPIC EVOLUTION THROUGH THE RESHUFFLING OF PIGMENTATION GENES

物种形成或新物种的起源通常是一个缓慢的过程，起源于长期的地理隔离和最终的突变积累。在快速辐射中，许多物种在短时间内聚集，这为研究导致进化和物种形成的遗传和生态环境提供了难得的机会。一种可能的快速进化机制是通过混合和重组可能已经存在于其他物种中的旧基因变异，形成新的组合。杂交可以为快速产生新的遗传组合提供来源。这个过程可以导致新特征的快速进化，比如颜色模式，而不需要很长时间来产生新的相关突变。颜色是动物交流的核心，调节配偶选择等关键行为，随着时间的推移，这些行为可以启动物种形成过程。这项研究将集中在一组南美鸟类，卡布奇诺种子捕食者（孢子属）。这些鸟类在基因上非常相似，但主要是在与羽毛色素沉积有关的基因附近的变异上区分出来的。该项目将结合进化生物学家和材料科学家的专业知识，了解羽毛的颜色是如何演变和推动快速进化的。这项研究将有助于更好地理解颜色产生背后的化学、结构和遗传机制。它还将探索这些变化是如何促进物种形成的。该项目将为学生提供培训机会，研究结果将通过流行的网络平台传达给广泛的受众。本研究将首先详细研究羽毛颜色产生的机制，包括色素组成和不同颜色羽毛的纳米和微观结构特性。这种对颜色表型的详细了解将与在可比发育时期取样的生长羽毛毛囊的基因表达数据相结合。最后，利用以往对这些分类群的种群基因组研究结果和新的转录数据，建立颜色多样性和图案产生的机制和进化模型。该项目的更广泛的影响包括一个基于交互式多媒体的模块，该模块由康奈尔鸟类学实验室主持，研究鸟类羽毛着色背后的机制（每年约有1000万次浏览）。该项目还将作为一个平台，为寻求应用基因组技术来回答自己研究问题的学生举办研讨会。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。

Speciation, or the origin of new species, is generally a slow process, originating from long periods of geographic isolation and the eventual accumulation of mutations. Rapid radiations, in which many species accumulate in a short period of time, represent rare opportunities to study the genetic and ecological contexts that lead to evolution and speciation. One possible mechanism for rapid evolution is through mixing and reassembling old genetic variants, which may already exist in other species, into novel combinations. Hybridization may provide the source for the rapid generation of new genetic combinations. This process can lead to the rapid evolution of novel traits, like coloration patterns, without the long period required for new relevant mutations to arise. Coloration is central to animal communication, mediating key behaviors like mate choice, which over time can kickstart the speciation process. This research will focus on a group of South American birds, the capuchino seedeaters (genus Sporophila). These birds are remarkably similar genetically yet are primarily differentiated at variants near genes involved in feather pigment deposition. This project will combine expertise from evolutionary biologists and materials scientists to understand how plumage coloration evolves and fuels rapid evolution. The proposed research will lead to a better understanding of the chemical, structural, and genetic mechanisms behind color production. It will also explore how these changes contribute to speciation. The project will enable student training opportunities and the results from this research will be communicated to a broad audience through popular web platforms.This research will first consist of a detailed study of the mechanisms behind color production in feathers, including the pigment composition and the nano- and micro-structural properties of feathers of different colors. This detailed understanding of coloration phenotypes will be combined with gene expression data from growing feather follicles sampled at comparable developmental times. Finally, the results from previous population genomic studies on these taxa and the new transcriptional data will be used to build a mechanistic and evolutionary model for how color diversity and patterning are generated. The broader impacts of this project include an interactive multimedia-based module on the mechanisms behind avian plumage coloration hosted by the Cornell Lab of Ornithology (~10 million views per year). The project will also be used as a platform to host a workshop for students who seek to apply genomic techniques to answer their own research questions.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.