Doctoral Dissertation Research: A model system for understanding the evolution of human language

语言是人类区别于其他所有物种的一个特征，研究人员有兴趣了解复杂语言是如何、何时以及为什么在古人类中进化的。这个博士论文项目将使用一个非人类模型来理解与增加社会学习和发声行为灵活性相关的神经遗传变化。这些数据将与人类和黑猩猩的基因组数据进行比较，以确定鸟鸣和人类语言进化中潜在的共同进化机制。通过阐明支持在模型系统中学习更灵活的发声行为的听觉感知的分子机制，这项研究可能有助于我们了解人类言语的正常功能和障碍。该项目还将包括在旧金山弗朗西斯科湾区的公众和K-12科学推广活动。该项目将实证研究与白背文鸟（WBM）/孟加拉雀（BF）鸣禽系统中发声学习和行为灵活性增加相关的遗传和进化过程。然后，研究人员将调查与其他灵长类动物有关的灵活的人类声乐学习能力进化中潜在的类似遗传和功能途径。该项目的具体目标包括：（i）利用两种鸟类品系内个体的全基因组测序和随后的积极或放松选择特征扫描，调查BF相对于WBM的发声行为变化背后的进化力量，从而鉴定在这种转变中修饰的候选基因;（ii）分析BF和WBM之间与成人发声灵活性差异相关的神经功能的遗传调节差异，通过比较暴露于不熟悉的同种歌曲的BF和WBM成年男性的主要鸟鸣相关脑区的全转录组的基因表达的测量;以及（iii）将鸟鸣数据与通过研究人类与密切相关的灵长类动物（例如黑猩猩）的差异所提供的神经解剖学和基因组数据进行比较，以识别可能的进化平行性。

Language is a trait that sets humans apart from all other species, and researchers are interested in understanding how, when, and why complex language evolved in hominins. This doctoral dissertation project will use a non-human model to understand neuro-genetic changes that correlate with increased social learning and flexibility of vocal behavior. These data will be compared with human and chimpanzee genomic data to identify potential shared evolutionary mechanisms in the evolution of birdsong and human language. By illuminating the molecular mechanisms of auditory perception that support learning of a more flexible vocal behavior in the model system, the research may shed light on our understanding of normal functionality and disorders of human speech. The project will also include public and K-12 science outreach activities in the San Francisco Bay Area.This project will empirically investigate the genetic and evolutionary processes that correlate with increased flexibility of vocal learning and behavior in the White-Backed Munia (WBM)/Bengalese Finch (BF) songbird system. The researchers will then investigate potentially analogous genetic and functional pathways involved in the evolution of flexible human vocal learning capacities with respect to those of other primates. Specific aims of the project include: (i) an investigation of the evolutionary forces underlying the changes in vocal behavior in BF relative to WBM utilizing whole-genome sequencing of individuals within the two bird strains and subsequent scans for signatures of positive or relaxed selection, thus allowing identification of candidate genes modified in this transition; (ii) an analysis of genetically regulated differences in neurological function correlated with differences in the flexibility of adult vocal production between BF and WBM, by comparing measures of gene expression for whole transcriptomes from main birdsong-related brain areas of BF and WBM adult males exposed to unfamiliar conspecific song; and (iii) a comparison of the birdsong data to neuroanatomical and genomic data provided by studies of human divergence from closely related primates (e.g. chimpanzee) to identify possible evolutionary parallelisms.