Collaborative Research: Admixture mapping of a hybrid zone to test Tinbergen's emancipation hypothesis

了解基因如何导致不同物种的行为特征不同是进化生物学的一个主要目标。这个项目试图测试丁伯根60年前提出的解放假说，以了解两种蜂鸟之间的杂交区域是如何产生一种新行为的。这种新奇的行为是一种求偶行为，是一种物种，艾伦的蜂鸟，而不是另一种，鲁弗斯蜂鸟。在这个被称为“钟摆展示”的刻板印象中，雄鸟在雌鸟身上来回飞翔，同时用翅膀发出独特的声音。研究人员将记录400只鸟在这两个物种之间的杂交区域内的表现，然后通过对这400只鸟的基因组进行测序，寻找与行为的个别组成部分相关的基因。理解一种行为是如何一分为二的，将揭示行为如何演变的基本机制。此外，这笔助学金将培训不同背景的学生，并通过资助购买一台“声学相机”，帮助加州河滨聋人学校，让聋人儿童通过这种新发明的可视化方式学习更多关于声音的知识。由于一个行为如何分裂成两个“准孤儿”的遗传基础尚未被证明适用于任何行为，这里提出的分析旨在第一次做到这一点。这项为期3年的研究有三个目标：(1)杂交区定位和临床分析：表型、基因型和选择(2)：复杂显示行为的序列分析，(3)：行为和形态的混合定位。这些目标将提供关于感兴趣的显示性状的选择的信息，并分别使用表型和遗传型数据直接检验顺形假说。目前的数据表明，在基因组编码区内的物种之间没有固定的遗传差异，这暗示着准形态行为可能是由两个物种之间的基因调控差异驱动的，而不是相似基因的结果。就像对遗传基础的研究改变了现代对形态多样性的看法一样，对杂交区内不同行为背后的基因进行直接评估，将有助于对复杂的运动模式如何进化进行首批测试之一。该项目将通过为康奈尔大学的麦考利图书馆、圣地亚哥自然历史博物馆和圣地亚哥州立大学生物多样性博物馆增加声音、视频和标本来建设基础设施。

Understanding how genes cause the behavioral traits of different species to be different is a major goal of evolutionary biology. This project seeks to test the emancipation hypothesis proposed by Tinbergen 60 years ago to understand how a novel behavior arises by using a hybrid zone between two species of hummingbirds. The novel behavior is a courtship display that is performed by one species, Allen's Hummingbird, and not the other, Rufous Hummingbird. In this stereotyped display, called the 'pendulum display', the male flies back and forth over a female while producing distinctive sounds with his wings. The investigators will record displays from 400 birds from within a hybrid zone between these two species, and then search for genes associated with individual components of the behavior, by sequencing the genomes of these 400 birds. Understanding how one behavior splits into two will reveal a fundamental mechanism of how behavior evolves. Additionally, this grant will train of students of diverse backgrounds, and enable outreach to the California School for the Deaf, Riverside by funding purchase of an 'acoustic camera', allowing deaf children to learn more about sound through this newly invented way of visualizing it. As the genetic underpinnings of how one behavior splits into two 'paramorphs', alternate forms of a previously unitary character, have not been demonstrated for any behavior, the analyses presented here aim to do so for the first time. This 3-year study has three objectives: (1) Hybrid zone mapping and cline analysis: phenotype, genotype, and selection (2): Sequence analysis of complex display behavior, and (3): Admixture mapping of behavior and morphology. Together these objectives will provide information about selection on the display traits of interest, and test the paramorph hypothesis directly, using phenotypic and genotypic data respectively. Current data indicate no fixed genetic differences between the species within coding regions of the genome, hinting that the paramorphic behavior could be driven by differences in gene regulation between the two species, rather than as the result of a paralogous gene. Just as the modern view of morphological diversity was transformed by the study of its genetic basis, a direct assessment of the genes underlying a behavior that varies across a hybrid zone will allow one of the first tests of how a complex motor pattern has evolved. This project will build infrastructure through addition of sound, video, and specimens to the Macaulay Library at Cornell University, San Diego Natural History Museum and the SDSU Museum of Biodiversity.