Collaborative Research: The geological and paleoecological contexts of early Miocene hominoid evolution

该奖项全部或部分由《2021年美国救援计划法案》（公法117-2）资助。本项目通过对一组地理上受限制的化石地点的年代学、古生态学和物种多样性的进一步了解，研究了时间和环境在早期猿类适应性进化中的作用。研究设计包括一系列化石挖掘，以发现早期猿类及其栖息地的新证据，并结合实验室分析，旨在帮助综合和解释这些发现。该项目的科学意义在于在特定的、高度确定的时间和生态背景下记录早期猿类的适应多样性，对解释包括人类在内的后来猿类的起源和多样化具有重要的下游意义。更广泛地说，该项目通过针对代表性不足的群体的培训机会扩大了对研究的参与，通过将宝贵但目前无法获得的实地记录数字化来增强科学基础设施，并通过针对博物馆和公立学校的外联活动增加公众对科学的参与。化石和分子证据表明，人类和类人猿的主要谱系在中新世早期（约23-16 Ma）分化。在这段时间里，猿类物种的多样性和适应性大大超过了这一群体的现代变异，这使得解释现存猿类和人类共有的一系列特征出现的进化顺序和生态背景变得困难。这个项目围绕着一个核心问题展开：早期猿类之间的差异与古环境、年龄的差异有关，还是两者兼而有之？为了弄清这些关系，研究人员有三个具体目标：(1)建立早期猿类化石遗址的严格年表；(2)对采样不足的类人猿分布区进行高分辨率古生态重建；(3)记录中新世早期猿类物种的多样性。化石挖掘是在一系列的露头进行的，以更好地记录猿的多样性，地质背景和栖息地参数。该项目在相关地层剖面上采用辐射地层学和磁地层学（目的1）；沉积学、同位素和古生物学分析（目标2）；以及新的类人猿化石标本的比较、形态计量学和系统发育分析（Aim 3）。这些研究结果的整合使研究人员能够将猿类和人类谱系中关键特征出现的时间和生态参数置于背景中，并随后解释这些早中新世灵长类动物群落如何促进灵长类动物在广阔地区的分布。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2). This project examines the roles of time and environment in the adaptive evolution of early apes by advancing knowledge about the chronology, paleoecology, and species diversity for a set of geographically restricted fossil localities. The research design includes a series of fossil excavations to uncover new evidence of early apes and their habitats, combined with laboratory analyses designed to aid in synthesizing and interpreting these discoveries. The scientific importance of this project lies in documenting early ape adaptive diversity within specific, highly-resolved chronological and ecological contexts, with major downstream implications for interpreting the origin and diversification of later apes, including hominins. More broadly, this project expands participation in research through training opportunities targeted to underrepresented groups, enhances scientific infrastructure by digitizing invaluable but currently inaccessible field records, and increases public engagement with science through outreach activities aimed at museums and public schools. Fossil and molecular evidence indicate that the major lineages of humans and apes diverged during the early Miocene (ca. 23-16 Ma). The diversity of ape species and adaptations during that time greatly exceeds modern variation in this group making it difficult to interpret the evolutionary sequence and ecological contexts in which the suite of features shared by living apes and humans appeared. This project is organized around the central question: Are differences among early apes tied to differences in paleoenvironments, ages, or both? To clarify these relationships, researchers pursue three specific aims: (1) establishing a rigorous chronology of early ape fossil sites; (2) generating high-resolution paleoecological reconstructions for undersampled ape localities; and (3) documenting the diversity of ape species during the early Miocene. Fossil excavations are conducted at a series of outcrops to better document ape diversity, geological contexts, and habitat parameters. The project employs radiometric and magnetostratigraphy at correlated stratigraphic sections (Aim 1); sedimentological, isotopic, and paleontological analyses (Aim 2); and comparative, morphometric, and phylogenetic analyses of new fossil ape specimens (Aim 3). Integration of these study results can enable the researchers to contextualize the timing and ecological parameters associated with the emergence of key characteristics in the ape and human lineage, and to subsequently interpret how these early Miocene primate communities contributed to the distribution of primates across broad regions.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.