Doctoral Dissertation Improvement: The evolution and genetic basis of primate brain cortical gyrification in a pedigreed Papio population

认知能力的提高与大脑体积的急剧增加有关，这是灵长类动物的一个标志。认知与大脑皮层中神经元的数量和大脑中信息处理的连接网络直接相关。皮质折叠(脑回)的增加使更多的神经元被包含在脑壳的体积内，大脑皮层上的褶皱和脊状结构的排列表明了潜在的神经网络连接区域。这篇论文是由华盛顿大学的伊丽莎白·阿特金森在詹姆斯·切弗鲁德博士的指导下进行的，使用了一个纯系的狒狒种群来评估灵长类动物皮质折叠的遗传基础和结构。然后，它进一步研究在狒狒中发现的基因组区域，以确定自然选择在改变灵长类家族树上的基因DNA序列中的作用。提出的问题包括：大脑皮层的组织结构是模块化的吗？在生物体的一生中，在子宫内一起发育或共同工作的大脑区域也是一起遗传的吗？大脑皮层对发育噪声的敏感性有多大？哪些染色体区域和基因会影响大脑功能和皮质特征的变异？是否有证据表明，影响皮质特征的基因已经在进化规模上发生了选择性的改变？总体而言，这个项目解决了人类和灵长类大脑进化中的关键问题，包括大脑形态的遗传结构，灵长类不同的认知策略，以及导致它们形成的进化机制。除了解决灵长类动物大脑形态和认知的遗传学问题，这个项目还将包括指导来自通常在科学中代表性较低的种族和社会经济群体的本科生和当地高中生，在圣路易斯市中心的学校教授进化论概念，进一步推动研究生运营的科学推广计划的努力，并在会议和会议上向其他科学家传播该项目的显著发现。参与这个项目将促进一名贫困的圣路易斯高中生的科学生涯和履历，他在2013年夏天的课程中得到了密切的指导，否则他们在学术发展的早期阶段几乎没有机会从事科学研究。

Elevated cognition, related to the dramatic increase in brain volume, is a hallmark of the primates. Cognition is directly related to the number of neurons in the cerebral cortex and the connectivity network underlying information processing in the brain. Increased cortical folding (gyrification) allows for more neurons to be contained within the volume of the braincase and the arrangement of folds and ridges across the cerebral cortex is an indication of the underlying neural network connecting regions. This dissertation project by Elizabeth Atkinson (Washington University), under the supervision of Dr. James Cheverud, uses a pedigreed baboon population to assess the genetic basis and structure of cortical folding in primates. It then further investigates the genomic regions identified in baboons to determine the role of natural selection in altering the DNA sequence of genes across the primate family tree. Questions addressed include: Is the organizational structure of the cerebral cortex modular? Are brain regions that develop together in utero or work together throughout an organism's life also inherited together? How susceptible to developmental noise is the cerebral cortex? What chromosomal regions and genes affect variation in brain function and cortical traits? Is there evidence that genes affecting cortical traits have been selectively altered at an evolutionary scale? Overall, this project addresses critical questions in human and primate brain evolution, including the genetic architecture of brain morphology, differing cognitive strategies across the primate clade, and the evolutionary mechanisms responsible for their formation.In addition to addressing issues of the genetics of brain morphology and cognition in primates, this project also will involve mentoring undergraduates and local high school students from ethnicities and socioeconomic groups typically underrepresented in the sciences, teaching evolutionary concepts at inner-city St. Louis schools, furthering the efforts of a graduate student-run program for science outreach, and disseminating the notable findings from this project to other scientists at meetings and conferences. Participating in this project will further the scientific career and curriculum vitae of an underprivileged St. Louis high school student, mentored closely over the course of the summer of 2013, who otherwise would have few opportunities to engage in scientific research at this early point in their academic development.