Doctoral Dissertation Research: Unraveling primate supraordinal relationships: Insights from plesiadapiform cranial morphology

博士论文研究：揭示灵长类动物的超序关系：来自 plesiadapiform 颅骨形态的见解

• 批准号: 2216582
• 负责人: Stephen Chester
• 金额: $ 2.74万
• 依托单位: CUNY Brooklyn College
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-08-01 至 2024-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2216582&HistoricalAwards=false
• 关键词: Doctoral; Dissertation; Research; Unraveling; primate

Central to unraveling the origin of primates - the mammalian group to which humans belong - are the fossils of plesiadapiforms, extinct members of a group (Euarchonta) consisting of primates and closely related mammals. While some plesiadapiforms have long been suggested to share characteristics with some contemporary primates, additional analyses of the plesiadapiforms using newer, state-of-the-art methodologies can further advance our understanding of primate origins. This doctoral dissertation project uses methods such as high-resolution X-ray micro computed tomography (μCT) to analyze and compare the cranial anatomy of plesiadapiforms to that of extant primates and other placental mammals. Detailed cranial comparisons are generated that can add to the evaluation of evolutionary relationships among plesiadapiforms, extant primates, and other euarchontan mammals, in the context of a new evolutionary tree. This project also provides numerous opportunities for outreach through mentorship, public science engagement events, and data sharing. Insights from this project can be incorporated into programs that facilitate participation from groups underrepresented in STEM. The investigators also train undergraduate and master’s students in aspects of CT scan data processing, 3D printing, computer coding, and basic fossil preparation. The investigators plan to make all data generated from this project, such as CT scan data and data matrices, freely available on public online repositories to allow for repeatability and to enable future studies on primate evolution.Plesiadapiform crania have traditionally played an important role in hypotheses about primate origins but remain poorly understood because they are unknown for a large majority of plesiadapiform species and because many of the known cranial specimens have not been analyzed using modern CT techniques. This study uses modern high-resolution CT technology to document new plesiadapiform cranial anatomy, reevaluate previously published cranial descriptions, and make thorough cranial comparisons among primates and other placental mammals. These data are incorporated into a new character-taxon matrix that is analyzed using both parsimony and Bayesian phylogenetic methods to assess evolutionary relationships. Results from these analyses can allow investigators to assess (i) which, if any, cranial features are uniquely shared among plesiadapiforms and primates of modern aspect, (ii) interrelationships among plesiadapiform families, and (iii) hypotheses of plesiadapiform evolutionary relationships within Euarchonta. Ultimately, these new data can provide clarity on previously proposed shared cranial features among plesiadapiforms and primates of modern aspect and will promote a better understanding of the divergence of primates from other mammals and the first steps in primate evolutionary history.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

灵长类动物（人类所属的哺乳动物群）起源的核心是近足类动物的化石，这是一个由灵长类动物和密切相关的哺乳动物组成的群体（Euarchonta）的灭绝成员。虽然一些plesiadapiforms长期以来一直被认为与一些当代灵长类动物有共同的特征，但使用更新的最先进的方法对plesiadapiforms进行额外的分析可以进一步促进我们对灵长类动物起源的理解。本博士论文项目使用高分辨率X射线显微计算机断层扫描（μCT）等方法来分析和比较plesiadapiforms与现存灵长类和其他胎盘哺乳动物的颅骨解剖结构。详细的颅骨比较生成，可以添加到plesiadapiforms，现存的灵长类动物，和其他euarchontan哺乳动物之间的进化关系的评价，在一个新的进化树的背景下。该项目还通过导师制、公共科学参与活动和数据共享提供了许多外展机会。该项目的见解可以纳入促进STEM中代表性不足的群体参与的计划。研究人员还对本科生和硕士生进行了三维CT扫描数据处理、3D打印、计算机编码和基本化石制备方面的培训。研究人员计划将该项目产生的所有数据，如CT扫描数据和数据矩阵，在公共在线知识库上免费提供，以允许重复性并使未来的灵长类进化研究成为可能。近适应形头骨传统上在灵长类起源的假设中发挥了重要作用，但仍然知之甚少，因为它们对大多数近适应形物种都是未知的，而且许多近适应形物种的头骨都是由人类进化而来的。已知的颅骨标本还没有使用现代的CT技术进行分析。这项研究使用现代高分辨率CT技术来记录新的plesiadapiform颅骨解剖结构，重新评估先前发表的颅骨描述，并在灵长类动物和其他胎盘哺乳动物之间进行彻底的颅骨比较。这些数据被纳入一个新的字符分类矩阵，使用简约和贝叶斯系统发育方法进行分析，以评估进化关系。这些分析的结果可以让研究者评估（i）如果有的话，哪些颅骨特征在plesiadapiforms和现代方面的灵长类动物中是唯一共享的，（ii）plesiadapiforms家族之间的相互关系，以及（iii）真孔达内plesiadapiforms进化关系的假设。最终，这些新的数据可以澄清之前提出的在近适应形类和现代灵长类之间共享的颅骨特征，并将促进更好地理解灵长类与其他哺乳动物的分歧以及灵长类进化史的第一步。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。