Doctoral Dissertation Research: The ecological context of early ape evolution

这个博士论文项目在哺乳动物群落进化的更广泛的背景下研究了类人猿的早期多样化。利用丰富的化石收藏，研究人员对来自多个研究充分的地点的哺乳动物组合进行了表征，以研究时间、空间和环境因素如何影响哺乳动物的群落结构。这个项目的科学意义在于提供了一个哺乳动物进化的比较背景，以更好地了解类人猿和人类谱系主要适应的生态环境。更广泛地说，该项目可以通过为STEM研究中代表性不足的群体的本科生提供研究生培训和研究机会，扩大对科学的参与，从而对科学和社会产生重大影响。通过该项目汇编的古生物数据的关系数据库计划通过明尼苏达大学的数据库(DRUM)向科学家和教育工作者公开分发。其他成果将通过同行评议的出版物、会议报告和旨在为公立学校和博物馆提供科学参与的公共宣传机会提供。类人猿谱系的早期分化主要记录在中新世早期(约23-16 Ma)，在此期间建立了类人猿-人类支系的几个主要适应特征。尽管这一时期的类人猿化石一直是密集研究的对象，但在哺乳动物群落进化的更广泛背景下正确定位这些物种的多样性所做的工作很少。这个项目提出了一个中心问题：环境、时间和地理距离如何影响早中新世哺乳动物群落的结构？利用大型化石组合，本项目探讨了四个具体问题：1)主要采集区的化石组合是否代表了哺乳动物群落结构的差异？2)哺乳动物群落结构的变化是否跟踪了相关的古生态指标所推断的环境差异？3)在年龄上最接近的组合中，哺乳动物的群落结构最相似吗？4)哺乳动物群落结构的相似性是否随着群落间地理距离的增加而降低？这些问题是通过分析13个化石地点的哺乳动物群落结构来解决的，这些化石地点在年龄和古环境方面已经有了很好的特征。通过将哺乳动物群落的演替置于时间、地理和环境背景中，这个项目可以让我们了解这些因素是如何影响哺乳动物物种之间的变化的，从而澄清在类人猿和人类谱系中发生重大适应的生态参数。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

This doctoral dissertation project examines the early diversification of apes within the broader context of mammalian community evolution. Leveraging rich fossil collections, the investigators characterize mammal assemblages from multiple, well-studied localities to examine how time, space and environmental factors impacted mammalian community structure. The scientific importance of this project lies in providing a comparative backdrop of mammalian evolution to better understand the ecological setting for major adaptations in the ape and human lineage. More broadly, this project can have significant impacts for science and society by expanding participation in science through graduate training and research opportunities for undergraduate students from groups underrepresented in STEM research. A relational database of paleontological data assembled through this project is planned for public distribution to scientists and educators via the Data Repository at the University of Minnesota (DRUM). Other results will be made available through peer-reviewed publications, conference presentations, and public outreach opportunities aimed at providing scientific engagement at public schools and museums. The early divergence of ape lineages, during which several major adaptive characteristics of the ape-human clade were established, is primarily recorded in the early Miocene (ca. 23-16 Ma). Although fossil apes from this time have been the subject of intense study, little work has been done to properly situate the diversity of these species within the broader context of mammalian community evolution. This project asks the central question: how did environment, time, and geographic distance influence the structure of early Miocene mammalian communities? Using large fossil assemblages, this project pursues four specific questions: 1) do fossil assemblages from major collecting areas represent differences in mammalian community structure? 2) do changes in mammalian community structure track environmental differences inferred from associated paleoecological proxies? 3) are mammalian community structures most similar among assemblages that are closest in age? and 4) does similarity in mammalian community structure decrease with increasing geographic distance between assemblages? These questions are addressed by analyzing the mammalian community structure across 13 fossil localities that are already well-characterized in terms of age and paleoenvironment. By situating mammalian community succession within temporal, geographic, and environmental contexts, this project can inform our understanding of how these factors influenced changes among mammal species, thereby clarifying the ecological parameters within which major adaptations in the ape and human lineage arose.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.