MCA: Ecological Constraints on Hominin Population Dynamics: Small Mammal Dental Shape Analyses as Novel Paleoecological Proxies

在这个职业生涯中期推进(MCA)项目中，首席研究人员开发了重建过去气候和环境的新方法，从而促进了关于气候、环境变化和人类人口动态之间联系的持续研究和辩论。该项目利用牙齿形状分析或生态计量学开发了高分辨率的古环境指标，该指标测量了牙尖的数量、大小和形状，并已被证明反映了许多动物群体的饮食和环境。然后，这个项目的研究成果可以被整合到研究中，以重建从200万年前到15,000年前的三个时期内人类占领的关键地区的古环境。该项目促进了人类学、生物科学和地球科学研究人员之间的创造性协同作用，并开发了一个公开可用的互动模型，该模型将有助于批判性地解决人类进化中对气候危机有直接影响的问题。该项目还促进了PI以及本科生的培养和研究计划。研究人员与其他古人类学专家合作，在重点领域研究小型哺乳动物的牙齿形状-饮食-生态，以研究广泛气候下的人类进化，包括：1)显微CT和激光三维(3D)扫描，2)图像和牙齿形状分析；3)地理信息系统(GIS)和空间分析；4)计算统计分析和编码。研究人员在现代物种的小型哺乳动物牙齿的3D数字扫描上测量牙齿生态测量变量(牙齿咬合拓扑学、拓扑学和地形)。利用地理信息系统，生态测量值与气候和生态参数相关联，建立了一种新的、定量的和稳健的技术来重建过去的环境。在化石牙齿上测量的牙齿生态测量变量使研究人员能够制作出不同史前时期的栖息地和气候分布的高质量地图。应用空间统计分析可以在三个特定的时间点定量测试气候变化和人类进化之间的联系：1.早期人从非洲扩散到欧亚大陆(250-70万年前)；2.尼安德特人的灭绝(160,000-40,000年前)；以及3.现代人类对最后一个冰河时代(26,000-15,000年前)的适应。该项目由生物人类学(SBE)和既定的激励竞争性研究计划(EPSCoR)共同资助。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。

In this Mid-Career Advancement (MCA) project, the principal investigator develops new methods to reconstruct past climates and environments, thus contributing to ongoing research and debates about the links between climate, environmental change, and human population dynamics. The project develops high resolution paleoenvironmental proxies using dental shape analysis or ecometrics, which measures the number, size, and shape of teeth cusps and has been shown to reflect diet and environment in many groups of animals. Research outcomes from this project can then be integrated into research to reconstruct paleoenvironments in critical areas of hominin occupation across three time periods dating from 2 million years ago to 15,000 years ago. This project fosters creative synergies between researchers in anthropology, biological sciences, and geosciences, and develops a publicly available interactive model which will help critically address questions in human evolution with direct implications for the climate crisis. The project also advances the training and research program of the PI as well as undergraduate students. The investigator partners with other paleoanthropological experts to acquire foundational skills to study the tooth shape-diet-ecology of small mammals in focal areas for studying human evolution across a wide range of climates, including: 1) micro-CT and laser 3-dimensional (3D) scanning, 2) image and tooth shape analysis; 3) Geographic Information Systems (GIS) and spatial analyses; and 4) computational statistical analyses and coding. The investigator measures dental ecometric variables (dental occlusal topology, topometry, and topography) on 3D digital scans of small mammal teeth of modern species. Using Geographic Information Systems, ecometric values are correlated with climatic and ecological parameters building a novel, quantitative and robust technique to reconstruct past environments. Dental ecometric variables measured on fossil teeth allow the investigator to produce a high-quality map of habitats and climate distributions across different prehistoric time frames. Applying spatial statistical analyses enables quantitatively testing the link between climate change and human evolution at three specific time junctures: 1. The dispersal of early Homo from Africa into Eurasia (2.5 – 0.7 million years ago); 2. The extinction of Neanderthal (160,000 – 40,000 years ago); and 3. The adaptation of modern humans to the last ice age (26,000- 15,000 years ago). This project is jointly funded by Biological Anthropology (SBE) and the Established Program to Stimulate Competitive Research (EPSCoR).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.