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

语言是人类区别于所有其他物种的特征，研究人员感兴趣的是了解人类如何、何时以及为什么进化出复杂的语言。这个博士论文项目将使用非人类模型来理解神经遗传学变化，这些变化与社会学习的增加和发声行为的灵活性有关。这些数据将与人类和黑猩猩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。通过阐明听觉感知的分子机制，支持在模型系统中学习更灵活的发声行为，该研究可能有助于我们理解人类语音的正常功能和障碍。该项目还将包括旧金山湾区的公共和K-12科学推广活动。该项目将对白背鸣鸟(WBM)/孟加拉雀(BF)鸣鸟系统中与提高发声学习和行为灵活性相关的遗传和进化过程进行实证研究。然后，研究人员将研究与其他灵长类动物相比，人类灵活的发声学习能力的进化过程中可能涉及的相似的遗传和功能途径。该项目的具体目标包括：(I)利用两个鸟类品系内个体的全基因组测序，并随后扫描积极或放松选择的签名，调查BF和WBM发声行为变化背后的进化力量，从而能够识别在这种转变中修改的候选基因；(Ii)通过比较BF和WBM成年雄性在接触不熟悉的同种特定歌曲时，主要鸟鸣相关脑区的整个转录基因表达的测量，分析BF和WBM之间神经功能的基因调控差异与成人发声灵活性的差异；以及(Iii)将鸟鸣数据与人类与近亲灵长类(如黑猩猩)的分化研究提供的神经解剖学和基因组数据进行比较，以确定可能的进化平行。

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.