Collaborative Research: Three-Dimensional Analysis of Dental Microwear in Primates

这个项目将开发一种新的，改进的方法来重建过去的人类和化石动物的饮食，利用他们牙齿上的微观使用磨损。最近对现存灵长类动物的研究表明，饮食与牙齿微磨损模式之间存在关联。在古代人的牙齿和许多灭绝动物的牙齿上都发现了微小的磨损。分析这种磨损的传统方法包括通过扫描电子显微镜（SEM）对牙齿磨损表面进行成像，然后在所得的显微照片上对单个磨损特征进行计数和测量。这种方法并不理想，因为扫描电镜不能在三维空间中提供牙齿表面的真实表示，并且因为单个特征的识别和测量是耗时的，主观的，并且容易受到观察者之间的高误差的影响。白光共聚焦显微镜和尺度敏感分形分析的最新发展消除了这些问题，有望对牙齿微磨损进行更客观、可重复的3D表征。该仪器提供三维坐标，表示表面的分辨率相当于大多数SEM微磨损研究使用的分辨率。分形分析提供了客观的、可重复的表面定量表征。最近的主要研究仪器拨款（NSF BCS-0215830）使我们能够购买一台白光共聚焦显微镜，带有尺度敏感分形分析软件。该提案要求资金将该技术用于牙齿微磨损分析，并为已知饮食的活体灵长类动物建立一系列3D微磨损模式的基线。这个基线将使我们能够通过牙齿化石上的微磨损模式来推断过去人类和灭绝动物的饮食。这种新方法将消除主要的误差来源，并增加解决物种之间差异的能力。此外，快速的表面表征将允许对大样本进行检查，以评估物种内部的变化，并在物种之间做出更精细的区分。此外，由于结果是可重复的，它将允许研究人员之间的数据进行直接比较，有望更好地了解我们遥远祖先的生活，以及其他化石物种。正如25年前的扫描电子显微镜和量化先进的微磨损研究一样，今天的共聚焦显微镜和计量分析也将如此。与其他科学努力一样，牙齿微磨损研究的历史显示了研究与技术创新之间的反馈循环。这种可重复的自动化过程将允许研究人员共享数据并激发该技术的新用途。我们现有基线系列的数据将在网上提供给所有感兴趣的人。该项目将由阿肯色大学协调，并将涉及阿肯色州、马萨诸塞州、马里兰州和宾夕法尼亚州的学生之间的培训和合作。该项目将支持阿肯色州的前沿研究，并为通常是第一代大学生的学生带来科学研究经验。它将包括技术培训，为这个地理上代表性不足的群体的学生做好技术部门工作的准备。

This project will develop a new, improved way to reconstruct the diets of past humans and fossil animals using microscopic use-wear on their teeth. Recent studies of living primates have shown associations between diet and patterns of dental microwear. Microscopic use-wear has been found on the teeth of past peoples and a broad range of extinct animals. Conventional approaches to analyzing this wear have involved imaging tooth wear surfaces by scanning electron microscopy (SEM), followed by counting and measuring individual wear features on resulting photomicrographs. This approach has not been ideal, because the SEM does not provide a true representation of tooth surfaces in three dimensions, and because identification and measurement of individual features is time-consuming, subjective and subject to high interobserver error. The recent developments of white light confocal microscopy and scale sensitive fractal analyses obviate these problems, promising a more objective, repeatable, 3D characterization of dental microwear. The instrument provides 3D coordinates representing surfaces at a resolution equivalent to that used by most SEM microwear studies. Fractal analyses provide objective, repeatable quantitative characterization of surfaces. A recent Major Research Instrumentation grant (NSF BCS-0215830) has allowed us to purchase a white light confocal microscope with scale sensitive fractal analysis software. This proposal requests funds to adapt this technology for dental microwear analysis, and to establish a baseline series of 3D microwear patterns for living primates with known diets. This baseline will allow us to infer diets of past peoples and extinct animals using microwear patterns on fossil teeth. This new approach will eliminate major sources of error, and increase power to resolve differences between species. Moreover, rapid surface characterization will allow examination of large samples to assess variation within species and to make finer distinctions between species. Further, because results are repeatable, it will allow direct comparisons of data between researchers, promising a better understanding of the lives of our distant ancestors, and other fossil species. Just as the SEM and quantification advanced microwear studies 25 years ago, so too will confocal microscopy and metrological analyses today. As with other scientific endeavors, the history of dental microwear studies shows a feedback loop between research and technological innovation. This repeatable, automated procedure will allow researchers to share data and stimulate new uses of this technology. Our data for the extant baseline series will be available on-line for all those interested.This project will be coordinated from the University of Arkansas, and will involve training and collaboration between students in Arkansas, Massachusetts, Maryland and Pennsylvania. This project will support cutting edge research in the state of Arkansas and bring a scientific research experience to students who are often first generation college attendees. It will include technology training that will prepare students from this geographically underrepresented group for technology sector jobs.