Galbany Jordi, Romero Alejandro, Mayo-Alesón Mercedes, Itsoma Fiacre, Gamarra Beatriz, Pérez-Pérez Alejandro, Willaume Eric, Kappeler Peter M, Charpentier Marie J E
Center for the Advanced Study of Hominid Paleobiology, Department of Anthropology, The George Washington University, Washington DC, United States of America; Departament de Biologia Animal - Secció d'Antropologia, Universitat de Barcelona, Barcelona, Spain.
Departamento de Biotecnología, Universidad de Alicante, Alicante, Spain.
PLoS One. 2014 Apr 14;9(4):e94938. doi: 10.1371/journal.pone.0094938. eCollection 2014.
Tooth wear in primates is caused by aging and ecological factors. However, comparative data that would allow us to delineate the contribution of each of these factors are lacking. Here, we contrast age-dependent molar tooth wear by scoring percent of dentine exposure (PDE) in two wild African primate populations from Gabonese forest and Kenyan savanna habitats. We found that forest-dwelling mandrills exhibited significantly higher PDE with age than savanna yellow baboons. Mandrills mainly feed on large tough food items, such as hard-shell fruits, and inhabit an ecosystem with a high presence of mineral quartz. By contrast, baboons consume large amounts of exogenous grit that adheres to underground storage organs but the proportion of quartz in the soils where baboons live is low. Our results support the hypothesis that not only age but also physical food properties and soil composition, particularly quartz richness, are factors that significantly impact tooth wear. We further propose that the accelerated dental wear in mandrills resulting in flatter molars with old age may represent an adaptation to process hard food items present in their environment.
灵长类动物的牙齿磨损是由衰老和生态因素引起的。然而，目前缺乏能让我们明确每种因素作用的比较数据。在此，我们通过对来自加蓬森林和肯尼亚稀树草原栖息地的两个野生非洲灵长类动物种群的牙本质暴露百分比（PDE）进行评分，对比了与年龄相关的臼齿磨损情况。我们发现，与稀树草原黄狒狒相比，生活在森林中的山魈随着年龄增长，其PDE显著更高。山魈主要以大型坚硬食物为食，如硬壳果实，并且生活在富含矿物石英的生态系统中。相比之下，狒狒会摄入大量附着在地下贮藏器官上的外源沙砾，但狒狒生活的土壤中石英的比例较低。我们的研究结果支持了这样一种假设，即不仅年龄，而且食物的物理特性和土壤成分，特别是石英含量，都是显著影响牙齿磨损的因素。我们进一步提出，山魈随着年龄增长牙齿磨损加速，导致臼齿变平，这可能是对其环境中存在的坚硬食物的一种适应。
