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。该项目旨在测试Tinbergen在60年前提出的解放假说，以理解如何利用两种蜂鸟之间的杂交区产生一种新的行为。这种新奇的行为是一种求偶行为，这种行为只发生在艾伦蜂鸟身上，而不是另一种红蜂鸟身上。在这种被称为“钟摆展示”的刻板展示中，雄性在雌性上空飞来飞去，同时用翅膀发出独特的声音。研究人员将记录来自这两种鸟类杂交区域的400只鸟的表演，然后通过对这400只鸟的基因组测序，寻找与这种行为的单个组成部分相关的基因。理解一种行为如何分裂成两种行为将揭示行为进化的基本机制。此外，这笔赠款将培训不同背景的学生，并通过资助购买“声学相机”，使加州河滨聋人学校能够扩展，让聋哑儿童通过这种新发明的可视化方式了解更多关于声音的知识。由于一种行为如何分裂成两个“准形态”的遗传基础，即先前单一特征的替代形式，尚未被证明适用于任何行为，因此本文的分析旨在首次这样做。这项为期3年的研究有三个目标：(1)杂交区定位和渐变分析：表型、基因型和选择；(2)复杂展示行为的序列分析；(3)行为和形态的混合定位。总之，这些目标将提供有关选择感兴趣的表现性状的信息，并分别使用表型和基因型数据直接检验准形态假设。目前的数据表明，在基因组的编码区域内，两种物种之间没有固定的遗传差异，这暗示着副胚行为可能是由两种物种之间基因调控的差异驱动的，而不是由同源基因驱动的。正如对形态多样性的现代观点是通过对其遗传基础的研究而改变的一样，对一种行为在杂交区域内发生变化的基因的直接评估，将使我们能够首次测试复杂的运动模式是如何进化的。该项目将通过向康奈尔大学麦考利图书馆、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添加声音、视频和标本来建立基础设施。

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.