Doctoral Dissertation Research: Binocular Vision and the Primate Origins Hypotheses

所有现存的灵长类动物都有向前的眼睛，这提供了大范围的双目视觉和精确的深度感知。本论文项目将通过行为实验和对现存灵长类动物的比较解剖学研究相结合的方式，检验关于灵长类动物双眼视觉进化起源的相互竞争的假说。该项目将创建一个免费访问的数据库，其中包括各种哺乳动物样本的CT扫描，这将使研究人员和临床医生受益。调查人员将通过几个外联计划让公众参与这项工作，这些计划旨在增加公众对科学研究的了解，并为科学代表性不足的群体的学生参与STEM。该项目还将通过一个项目促进几名本科生的培训，该项目旨在为第一代大学生和代表性不足群体的成员进行研究生研究做准备。为了确定在灵长类动物早期进化过程中，哪些生态因素导致了大范围双目视觉的进化，该项目将采用比较形态和实验方法。首先，研究人员将测量生态和系统发育不同的比较哺乳动物样本中的双目视野，以确定哪些生态变量与哺乳动物双目视野大小的增加有关。双眼视野大小将通过液体保存的标本的微型CT扫描进行测量，这些标本被碘染色，以使眼睛的软组织可见。其次，研究人员将通过实验评估双目视觉对于抓取和跳跃行为类型的功能重要性，而相互竞争的灵长类起源假说表明，选择这些行为是为了增加双眼视野宽度。夜间活动的小型链头犀牛将被拍摄到在正常条件下执行抓取和跳跃任务，并缩小双眼视野。这种研究双目视觉大范围功能意义的综合方法将为冠状灵长类起源的竞争适应场景提供测试。这个项目的结果将有助于解决关于灵长类的一个关键特征的长期争论。

All living primates have forward-facing eyes, which provide a large field of binocular vision and precise depth perception. This dissertation project will test competing hypotheses about the evolutionary origins of binocular vision in primates through a combination of behavioral experiments and comparative anatomical studies in living primates. The project will produce a freely accessible database of CT scans of a diverse sample of mammals, which will benefit researchers as well as clinicians. The investigators will engage the public in this work through several outreach programs aimed at increasing both public understanding of scientific research and participation in STEM for students from groups underrepresented in science. The project will also facilitate the training of several undergraduates through a program that prepares first generation college students and members of underrepresented groups for graduate research. To determine which ecological factors led to the evolution of a wide field of binocular vision during early primate evolution, this project will employ both comparative morphological and experimental methods. First, the investigators will measure binocular field in an ecologically and phylogenetically diverse comparative mammalian sample to determine which ecological variables are associated with increases in binocular field size across mammals. Binocular field size will be measured from micro-CT scans of fluid-preserved specimens that are iodine stained to render the soft tissues of the eyes visible. Second, the researchers will experimentally evaluate the functional importance of binocular vision for the types of grasping and leaping behaviors that competing primate origins hypotheses suggest selected for increased binocular field width. Small-bodied nocturnal strepsirrhines will be filmed performing grasping and leaping tasks under normal conditions and with reduced binocular visual field. This integrated approach to studying the functional significance of a wide field of binocular vision will provide a test of the competing adaptive scenarios for crown primate origins. The results of this project will help to address long-standing debates about a key feature of the primate order.