Last week I attended the 87th Annual Meeting of the American Association of Physical Anthropology in Austin, Texas. I presented research in a session called Tooth Wear in Evolutionary and Biocultural Perspectives that was organized by James T. Watson and Christopher W. Schmidt. I presented on the "Dental microwear texture analysis of the Late Upper Paleolithic/Neolithic humans at Tam Hang (Northern Laos)" . The research is a collaborative effort between myself and Christopher W. Schmidt, Ashley Remy, Laura Shackelford, and Fabrice Demeter that investigates how microscopic wear textures on the occlusal surfaces of molars reflects dietary variation within this group of foragers (and food-producers/farmers - see below) from the tropical environments of southeast Asia at the end of the Ice Age. Examples of 2D (grey) and 3D (color) dental microwear textures. The color differences help visualize the microwear on the tooth surfaces. Several variables are derived from the microscopic images to understand individual and group variation in diet-induced molar microwear. Our study on Tam Hang is a part of the larger "DENTALWEAR Project" directed by Christopher Schmidt at the University of Indianapolis. The DENTALWEAR Project compiles a massive dataset of microwear textures that encompass a large range of dietary variation. A global sampling of peoples practicing forms of foraging, farming, and pastoralist socioeconomic strategies provides a comparative framework for inferring aspects of dietary variation in prehistoric groups - like Tam Hang. Our results showed a high degree of variation in the microwear textures among the Tam Hang individuals. This could mean that the individuals exhibited broad spectrum foraging strategies typical of many hunter-gatherer groups at the end of the Ice Age and into the Holocene. This basically means that the people from Tam Hang probably had a wide dietary breadth - including a large range of animal and plant foods. However, some of the burials at Tam Hang may be intrusive. When the Neolithic (food-producing or agriculturalist) peoples of later periods settled in the region, they may have dug down into the Late Upper Paleolithic levels of the site when burying their dead. The skeletal material from Tam Hang was originally excavated during the 1930's, so it is difficult to reconstruct just how much mixing of the Upper Paleolithic and Neolithic archaeological contexts may have occurred. Therefore, what we think is "broad spectrum foraging" could also be an artifact of having samples from two different time periods mixed together. Future research will attempt to sort out this out. For anyone interested in the original abstract from the meeting: The human burials from Tam Hang provide a rare opportunity to study Late Pleistocene human paleobiology in a non-Western Eurasian context. As such, this study addresses dietary variation at Tam Hang using dental microwear texture analysis (DMTA). A white-light confocal profiler was used to examine phase II wear facets on molar casts following standard procedures. Complexity (Asfc), anisotropy (epLsar), and textural fill volume (Tfv) were calculated using scale-sensitive fractal analysis software (Sfraxâ and Toothfraxâ). Seven individuals had well-preserved microwear and were compared to previously published Pleistocene and Holocene groups. Tam Hang mean complexity (1.60) is high, and closest to Natufians and hard-diet foragers (Middle Woodland Indiana). However, two Tam Hang individuals have relatively low complexity (Asfc > 1.0) suggesting they ate softer foods, like meat. Mean anisotropy (0.0028) is low and most like the Vindija Neandertals, hard-diet foragers (Middle Woodland Indiana), and abrasive diet foragers (Middle-Late Archaic Kentucky). However, one individual has elevated anisotropy (0.0072) indicative of tough or fibrous food consumption. Mean Tfv is relatively low (26,509), but two sub-groupings in the Tam Hang sample indicates within group variation in the consumption of mechanically challenging foods. Overall, the microwear signature at Tam Hang is heterogeneous with some emphasis on hard food consumption, and idiosyncratic variation in meat and tough food consumption. There is no patterning by age, sex, or ablation status. High within sample variation may indicate broad spectrum foraging strategies, but we cannot rule out intrusive Neolithic burials in the Late Upper Paleolithic sample at Tam Hang. In a past paper (with Laura Shackelford and Fabrice Demeter) the practice of incisor ablation (the culturally motivated, intentional extraction of healthy teeth during the life of an individual) was addressed. That paper can be found here or here. Individuals from Tam Hang with a.) two; b.) three, c.) four, and d.) zero ablated teeth. In all cases, intentional extractions are marked with white arrows and the other missing teeth are due to postmortem (non-intentional) damage. Two examples from the University of Indianapolis DENTALWEAR Project are linked below. Both publications are open access:
Schmidt CW, Beach JJ, McKinley JI, and Eng JT. 2016. Distinguishing dietary indicators of pastoralists and agriculturists via dental microwear texture analysis. Surface Topography: Metrology and Properties 4(1):014008. Karriger WM, Schmidt CW, and Smith FH. 2016. Dental microwear texture analysis of Croatian Neandertal molars. PaleoAnthropology 2016:172-184. Comments are closed.
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John C. Willman
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