Abstract # 12484 Poster # 800:

Scheduled for Thursday, August 23, 2018 07:30 PM-09:30 PM: Session 521 (Concourse) Poster Presentation


MAINTAINING FUNCTIONALITY THROUGHOUT LIFE: THE ADAPTIVE VALUE OF MOLAR WEAR PATTERNS IN HOMINOID PRIMATES

L. Nadal 1, L. M. Martinez1, A. Romero2, B. Gamarra3, J. Galbany4 and A. Pérez-Pérez1
1Dept. Biología Evolutiva, Ecologia i Ciències Ambientals, Universitat de Barcelona, Av. Diagonal 643, Barcelona 08028, Spain, 2Dept. Biotecnología, Universidad de Alicante, 3School of Archaeology, University College Dublin, 4Dept. Anthropology, The George Washington University
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Dental wear represents an important selective pressure, since it compromises the structural integrity of the tooth. The purpose of this study was to characterize occlusal wear patterns in hominoid primates with differing diets to determine its effects on tooth functionality. Topographic analyses were conducted on 3D scans of second lower molars, showing different levels of wear, of four hominoid genera: Gorilla (n=38), Pan (n=33), Pongo (n=23) and Hylobates (n=18). Molar topographic data were obtained by applying the MorphoTester package to characterize curvature, crown relief, and surface complexity. ANOVA tests showed complexity means to differ significantly with wear in folivorous and frugivorous/folivorous genera, Gorilla (F(4,33)=6.01, p=0.001) and Hylobates (F(2,15)=5.51, p=0.01), the latter also showing significant differences in relief (F(2,15)=11.93, p=0.001). Moreover, curvature and relief means showed significant differences in different stages of wear in the frugivorous genera, Pan (Curvature: F(3,30)=3.28, p=0.03, Relief: F(3,30)=5.54, p=0.004) and Pongo (Curvature: F(3,19)=7.96, p=0.001, Relief: F(3,19)=5.1, p=0.009). These results suggest that leaf eaters have adapted to retain curvature, with committed folivores also retaining relief values, both associated with a higher processing efficiency of foliage. Furthermore, frugivorous species tend to retain complexity, associated with increased grinding capacity. We conclude that wear is not detrimental for tooth functionality as commonly thought, and that natural selection favors shapes that retain functional forms for a longer period of time despite the presence of wear.