Intraspecific Variation in Primate Dental Wear: The Role of Environment and Diet

牙齿的整体磨损模式(即牙齿的宏观磨损)反映了食品加工的累积效应，不同的牙齿磨损影响生存、健康和生活史。牙齿的结构(咬合形态、牙釉质厚度、牙釉质结构)通常很好地适应特定的饮食，因此即使牙齿磨损，它们仍然能够充分处理食物。牙齿磨损的原因多种多样，包括食物特性(磨损)、化学侵蚀、牙齿之间的接触(磨损)和/或外来的砂砾。然而，磨损的机理仍然知之甚少。该项目的目标是确定单一灵长类动物(狐猴)牙齿磨损的直接原因，跨越和在多个栖息地内，以及在高度季节性的环境中(马达加斯加南部)跨季节，从而为了解灵长类动物，进而哺乳动物的牙齿磨损的种内变化提供一个关键框架。这个项目将结合关于食物特性、植物植硅体和外源砂砾的新数据，以及关于摄食行为和生态的详细知识，来评估每种物质对牙齿磨损的作用。牙齿的宏观磨损模式将通过牙齿地形分析进行评估，而种植石和砂砾对牙齿磨损的影响将通过牙齿微磨损纹理分析来确定。智力价值由于这项研究独一无二地结合了对灵长类动物行为、植物用途、栖息地差异、植物食物特性以及砂砾和植硅石的作用的直接了解，这些结果应该会告知这些过程如何共同作用，创造牙齿磨损模式的变异性。更广泛的影响该项目将帮助马达加斯加生物学专业的学生掌握必要的技能，为马达加斯加濒危野生动物的研究和保护做出贡献。它还将提供北达科他大学和阿肯色大学(这两个州都是EPSCoR州)的本科生研究机会，并将建立在该项目在美国和马达加斯加推广K-12的记录的基础上。

Patterns of overall tooth wear (i.e., dental macrowear) reflect the cumulative effects of food processing, with differential tooth wear affecting survival, health, and life history. The structure of teeth (occlusal morphology, enamel thickness, enamel structure) is generally well adapted to specific diets, so that even as teeth wear, they remain capable of adequately processing food. Tooth wear results from a variety of causes, including food properties (abrasion), chemical erosion, contact between teeth (attrition), and/or extraneous grit. However, the mechanics of wear remain poorly understood. The goal of this project is to identify the proximate causes of wear in a single primate species (Lemur catta), across and within multiple habitats, and across seasons in a highly seasonal environment (southern Madagascar), thus providing a critical framework for understanding intraspecific variation in primate, and thus mammalian, tooth wear. This project will combine new data on food properties, plant phytoliths, and exogenous grit, with detailed knowledge of feeding behavior and ecology, to assess the role of each on tooth wear. Patterns of dental macrowear will be assessed using dental topographic analyses, while the effects on tooth wear by phytoliths and grit will be determined using dental microwear texture analyses. Intellectual Merit As this study uniquely combines a direct understanding of primate behavior, plant use, habitat differences, plant food properties, and the role of grit and phytoliths, these results should inform how these processes work together to create variability in patterns of tooth wear. Broader Impacts This project will aid the development of Malagasy biology students with the skills necessary to contribute to the study and conservation of endangered wildlife in Madagascar. It will also provide undergraduate student research opportunities at the University of North Dakota and the University of Arkansas (both EPSCoR states), and will build on the project's record of K-12 outreach in the U.S. and in Madagascar.