I had the great privilege of contributing to a new article published in PLOS ONE yesterday that was coordinated by my colleague, Dr. Kristin Krueger, of Loyola University Chicago. The piece has been summarized nicely by Katherine J. Wu at PBS NOVA. I provide a short summary and a few additional thoughts here. Neandertal and early modern human anterior tooth-use Reconstructions of Neandertal behavior frequently call attention to their anterior tooth (incisor and canine) wear. Some incredible examples of extreme anterior dental wear are documented among some of the earliest well-published Neandertal fossils (for example: La Ferrassie and Forbe's Quarry) and the iconic photo by Erik Trinkaus of Shanidar 1's anterior dental wear (see below) is widely used to illustrate the phenomenon. This high degree of wear in the front teeth is most frequently interpreted as evidence that Neandertals used their "teeth-as-tools" or as a "third hand" regularly. In fact, it's often rare not to see a behavioral reconstruction of Neandertal that doesn't depict them using their "teeth as tools" in a museum display, artistic reconstruction, and television popular science documentaries. Above left: Shanidar 1 Neandertal with heavy anterior tooth wear (Photo: Erik Trinkaus). Above right: Artistic reconstruction of a Neandertal using its anterior teeth (as a "third hand") to clamp down on a piece of meat while they cut it into smaller pieces using a stone tool with their free hand. This behavior is also routinely called "stuff and cut" - a phrase that can be attributed to C. Loring Brace. Above: Artistic reconstruction of a Neandertal group from El Sidron Cave featuring a Neandertal woman using her teeth to assist in hide scraping activities. Another behavior that leaves traces on teeth is the use of toothpicks which I discuss elsewhere. Artwork by Emmanuel Roudier. The robust build of Neandertal skulls and their large anterior teeth are a stark contrast to the smaller teeth and more gracile skulls of modern humans. These morphological differences were coupled with the observations of heavy anterior dental wear, and many researchers saw aspects of Neandertal cranial and dental morphology as adaptations that helped dissipate the high bite forces and/or repetitive loading of the anterior teeth and face when engaging in the use of teeth-as-tools. This "Anterior Dental Loading Hypothesis" has held a prominent position in Neandertal research. But why use your teeth as tools? The technological capacities of the Neandertals were (and often still are) considered impoverished or inferior to those of Upper Paleolithic early modern humans. Thus, early modern humans were thought to possess a degree of technological ingenuity that reduced morphological selection for the robust cranial and dental features found in Neandertals and their predecessors. The anterior dental loading hypothesis and ideas of "Neandertal inferiority/modern human superiority" have been challenged on a number of grounds. However, dental wear can provide direct evidence for how the anterior dentition was used among Neandertals and early modern humans. However, few studies directly compare Neandertals and early modern human dental wear, and none have used dental microwear texture analysis to test these ideas. Above: The Shanidar 1 Neandertal (left) compared to an early modern human from Předmostí (right). Many cranial features, and the front teeth in particular, are quite large and "robustly built" in Neandertals but reduced in size and "gracile" in early modern humans. This is where our new paper jumps into the discussion. The research, coordinated by Dr. Krueger, uses dental microwear texture analysis of the surfaces of anterior teeth to explore similarities and differences in Neandertal and early modern human tooth-using behaviors. The results were surprising given the amount of previous research emphasizing behavioral and morphological differences between the two groups. We compared Neandertal and early modern human anterior dental microwear textures to each other as well as to a large comparative databases for human groups with considerable variation in temporal, ecological, geographic, and cultural backgrounds (see map below). While I have written elsewhere about how molar microwear texture can be used to reconstruct diets in Homo sapiens and Neandertals, the microwear textures on the anterior teeth are somewhat different. Incisors and canines are not only involved in the breakdown of food but are frequently used in a variety of non-dietary tasks. Therefore, dental wear on front teeth is a palimpsest of behavioral signatures related to dietary and non-dietary (using the “teeth-as-tools”) behaviors as well as various environmental factors (often related to the presence or absence of grit and dust). The excellent contextual information available for the human groups used for comparative purposes includes information on the diet, non-dietary behaviors, environment, and other factors that we use to interpret the results obtained for the Neandertals and early modern humans. Above: Map showing the location of human groups used to compare and contextuale the dental microwear texture results for Neandertals and early modern humans. Map is from Krueger 2015. Interestingly, we found that the Neandertals and early modern humans exhibited very similar anterior dental microwear texture results. The values for both of these Pleistocene human groups were closest to those of the Point Hope Tigara hunter-gatherers from Alaska in our comparative sample. The Tigara are known to have used their anterior teeth in a variety of non-dietary, clamping and grasping behaviors such as as processing/softening animal hides and working sinew into thread. Thus, one way of interpreting the data for Neandertals and early modern humans were engaging in a similar range of clamping and grasping behaviors with the front teeth. Clothing and hide processing are reasonable behaviors documented in bioarchaeological and ethnohistoric contexts. Above: Scatter plot of Neandertal and early modern human dental microwear texture values (Tfv = textural fill volume & epLsar = anisotropy) with 95% confidence interval ellipses. Note the extensive overlap in variation. Above: Means and 95% confidence intervals for textural fill volume (Tfv) and anisotropy (epLsar) for the Neandertal, early modern human, and Holocene/ethnohistoric comparative groups. Note the closeness of the means Tigara group to the Pleistocene humans. The colloquial meaning of "neandertal" reflects the long-held notion of a major behavioral gap that separates the Neandertals from "us". However, the scientific and public perception of the Neandertals is undergoing a sort of renaissance at present. Many behaviors once associated with modern humans - like the controlled use of fire or creation of cave art and personal ornaments - are now documented in Neandertal contexts. The dental evidence presented here is also significant given the long-held view that Neandertals relied so heavily on their bodies, teeth, and brawn over technological and cultural solutions to complete their daily activities whereas early modern humans were thought to use brains, culture, and technology over brawn. However, the dental evidence tells a different story - there's little noticeable difference between the Neandertals and early modern humans in terms of tooth-using behaviors. I am of the opinion that the presumption of a major behavioral gap has persisted for so long because early modern humans were so infrequently compared directly to Neandertals in so many analyses. Instead, Holocene and/or ethnohistoric peoples were generally used (and sometimes still are) as proxies for early modern humans from the Pleistocene. While it should be obvious that historical and contemporary hunter-gatherers from disparate locations (common examples come from East and South Africa, the Arctic, and Australia) are not equivalent to Ice Age hunter-gatherers from Europe, uncritical comparisons were (and occasionally still are) the norm in paleoanthropological research. The work presented here shows how direct comparisons between Neandertals and early modern humans blur the divisions once thought to exist for anterior tooth-using behaviors. Whereas the data from recent human groups can be used to refine interpretations of Pleistocene behavior rather than be used as proxies for the early modern human behavior. Lastly, this publication is available freely (open access) and all data is freely downloadable in the online supplemental information. This was a really fun piece to contribute to and I am really proud of how it turned out. Many thanks to the first author for the chance to collaborate! Really looking forward to seeing what research Dr. Krueger sinks her teeth into next.... References FREE FREE FREE DOWNLOAD!
Krueger KL, Willman JC, Matthews GJ, Hublin J-J, and Pérez-Pérez A. 2019. Anterior tooth-use behaviors among early modern humans and Neandertals. PLOS ONE 14(11):e0224573, doi.org/10.1371/journal.pone.0224573. Krueger KL. 2015. Reconstructing diet and behavior in bioarchaeological groups using incisor microwear texture analysis. Journal of Archaeological Science: Reports 1:29-37, http://dx.doi.org/10.1016/j.jasrep.2014.10.002. Krueger KL, and Ungar PS. 2009. Incisor microwear textures of five bioarcheological groups. International Journal of Osteoarchaeology 20(5):549-560, dx.doi.org/10.1002/oa.1093. Krueger KL, Ungar PS, Guatelli-Steinberg D, Hublin J-J, Pérez-Pérez A, Trinkaus E, and Willman JC. 2017. Anterior dental microwear textures show habitat-driven variability in Neandertal behavior. Journal of Human Evolution 105:13-23, http://dx.doi.org/10.1016/j.jhevol.2017.01.004.
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The significance of a single Neandertal tooth from Ciemna Cave in southern Poland that I worked on with an international team of collaborators has been published online in the Journal of Paleolithic Archaeology. The primary topics discussed in our paper concern the low number of Neandertal fossils in northern Central Europe despite the abundance of Middle Paleolithic archaeological sites in the region; and the particular details on the single Neandertal incisor recovered in Ciemna Cave. Of particular interest is the “toothpick groove” documented on the incisor. To date, three isolated teeth from Stajnia Cave are the only other Neandertal remains documented from archaeological sites in Poland. While there are other Neandertal remains from Central Europe (Švédův stůl [Ochoz], Kůlna Cave, Šipka Cave, Šal’a 1, Šal’a 2, Gànovce, Subalyuk, and Bordul Mare 1); they are few and fragmentary. However, there was extensive occupation of at least southern Poland into neighboring Moravia and the Carpathians during the Middle Paleolithic, so the general lack of Neandertal fossils in the region is puzzling. However, with so few fossils, it is all the more necessary to carefully document the few that are discovered. With this in mind, we carried out a detailed analysis of the single tooth from Ciemna Cave. Location of Ciemna Cave in relation to other Middle Paleolithic sites in Central Europe where Neandertal fossils have been discovered. We detail extensive damage to the crown and root of the tooth that occurred after death. While some of the damage can be attributed to natural processes like changes in humidity and abrasion from sediment, the degree of fragmentation and presence of only a single incisor still raises questions about how the tooth entered the archaeological record. During the late stages of carnivore scavenging, cranial bones can become very fragmented, teeth may become isolated, and these remains can be scattered over large areas. We also know that Ciemna Cave was a carnivore (primarily bear) den that was only inhabited by humans occasionally. In addition to bears, the remains of wolves, hyena, Lynx, and foxes have been identified in the layers contained the Ciemna 1 tooth. So, we propose that carnivores scavenging, fragmentation, and scattering of human remains could be one scenario for how the isolated tooth at Ciemna Cave entered into the archaeological record. Nevertheless, this scenario is difficult to confirm without direct evidence of carnivore tooth-marking or digestive corrosion on the Ciemna 1 fossil. Detailed photos of the Ciemna 1 Neandertal tooth. Despite the postmortem damage to the Ciemna 1 tooth, there is a well-preserved groove just below the enamel on the tooth root. We attributed this groove to the repetitive use of a probe – or “toothpick” – during this Neandertal's life. These so-called toothpick grooves are not uncommon in prehistoric contexts and are very well-documented among the earliest members of genus Homo and extremely well-documented among Neandertals. In fact, one of the teeth from Stajnia Cave also has a toothpick groove. Sometimes these grooves can be attributed to therapeutic activities, such as probing at inflamed gums or caries. In other cases, these grooves are attributed to hygienic behaviors – picking food and other gunk out from between your teeth. In our case, there is only a single tooth and it’s too fragmentary to clearly say whether the groove is a result of therapeutic or hygienic practices. However, it provides yet another case of this behavior among Neandertals. Detail images of the toothpick groove on the root of Ciemna 1. A) Dashed outline of the groove in the same view as B. B) Environmental scanning electron microscopy (ESEM) micrograph of the groove. C) ESEM micrograph creating by focus-stacking images for increased depth-of-field. D) Detail of microstriations in the labial portion of the groove using light microscopy. Scales are 1 mm (2 × 0.5 mm increments) Dr. Paweł Valde-Nowak will continue excavating at Ciemna Cave with his team this summer, and my fingers are crossed that more Neandertal fossils will be discovered.
This research was also presented a symposium I co-organizered with Libby W. Cowgill, Sheela Athreya, and Scott D. Maddux called From Pedestrian to Cerebral in the Pleistocene: A Symposium in Honor of Erik Trinkaus at the 88th Annual Meeting of the American Association of Physical Anthropologists, Cleveland, Ohio. Full Article: Willman JC, Ginter B, Hernando R, Lozano M, Sobczyk K, Stefański D, Szczepanek A, Wertz K, Wojtal P, Zając M, Zarzecka-Szubińska K, Valde-Nowak P. (2019). Paleobiology and Taphonomy of a Middle Paleolithic Neandertal Tooth from Ciemna Cave, Southern Poland. Journal of Paleolithic Archaeology, doi:10.1007/s41982-019-00026-4. More on the archaeology and excavations of Ciemna Cave: Valde-Nowak P, Alex B, Ginter B, Krajcarz MT, Madeyska T, Miękina B, et al. (2014). Middle Paleolithic sequences of the Ciemna Cave (Prądnik valley, Poland): the problem of synchronization. Quaternary International, 326, 125–145. https://doi.org/10.1016/j.quaint.2014.01.002. Valde-Nowak P, Alex B, Boaretto E, Ginter B, Sobczyk K, Stefański D, et al. (2016a). The Middle Palaeolithic sequence of Ciemna Cave. Some aspects of the site formation process. Quärtar, 63, 33–46. https://doi.org/10.7485/QU63_2. Valde-Nowak P, Alex B, Ginter B, Krajcarz MT, Madeyska T, Miękina B, et al. (2016b). Late Middle Palaeolithic occupations in Ciemna Cave, southern Poland. Journal of Field Archaeology, 41(2), 193–210. https://doi.org/10.1080/00934690.2015.1101942. Last week I had the opportunity to attend the XVIIe Congrès Mondial UISPP - Union Internationale des Sciences Préhistoriques et Protohistoriques in Paris, France where I participated in Session XXXI-1 Through time, space and species: implication of new discoveries, technological developments and data diffusion improvement in Biological Anthropology organized by Dominique Grimaud-Hervé, Carlos Lorenzo, Julie Arnaud. I presented collaborative work synthsizing research on the "Non-alimentary tooth-use in European Prehistory". The presentation brought together data across a wide span of time and space that have been studied so far by my colleagues (Alejandro Romero, Eulàlia Subirà, and Marina Lozano) and me. Much of the data we presented will contribute to the IDENTITIES Project.
An article I contributed to on dietary reconstructions of Neandertals from Hortus Cave was published online this week in Comptes Rendus Palevol. The research was a collaborative effort between Frank L’Engle Williams, Jessica L. Droke, Christopher W. Schmidt, Gaël Becam, Marie-Antoinette de Lumley, and me. This is another paper that stems from the DENTALWEAR Project directed by Christopher W. Schmidt at the University of Indianapolis that I referenced in an earlier post. Our study is interesting because the Hortus Neandertal sample includes a wide range of age variation: a juvenile, 4 adults, and an older adult (50+ years old - "old" by Pleistocene standards). The Hortus individuals also come from different stratigraphic sequences in the site which are associated with different climatic conditions. Thus, we were able to investigation patterning in diet by both age and in relation to climate. Two-dimensional photosimulations (left, grey images) and their 3D enamel surface reconstructions counterparts for the Hortus Neandertals. for (a) Hortus III, (b) Hortus IV, (c) Hortus V, (d) Hortus VI, (e) Hortus VIII and (f) Hortus XI. The ones for Hortus III and XI are quite similar. We found that the This plot above summarizes are results well. The bivariate plot contains data for two dental microwear texture variables (complexity [Asfc] and anisotropy [epLsar]) that are known to characterize human dietary variation well. The black arrows are generalizations about diet based on comparative data from 12 recent human foraging, farming, and pastoralist groups from the DENTALWEAR Project (Karriger et al., 2016). The variation in diet related to climate is shown by the box labeled "Sub-Phase Vb". The Sub-Phase Vb Neandertals group together which indicates similar dietary strategies during this period of greater coldness and aridity than other phases at the site. The dashed line shows that the adults group separately from the "older" adult and young (juvenile) individual. Thus, age also contributes to unique patterns of dental microwear texture at Hortus. Our results were fairly consistent with our predictions. We now have an even greater understanding of dietary variation and adaptability among the Hortus Neandertals, but also Neandertals in general. References:
Williams FLE, Droke JL, Schmidt CW, Willman JC, Becam G, and de Lumley M-A. 2018 Dental microwear texture analysis of Neandertals from Hortus cave, France / Analyse de la texture des de la micro-usure dentaire chez les Néandertaliens de la grotte de l’Hortus, France. Comptes Rendus Palevol. doi: https://doi.org/10.1016/j.crpv.2018.04.003 Karriger WM, Schmidt CW, and Smith FH. 2016. Dental microwear texture analysis of Croatian Neandertal molars. PaleoAnthropology 2016:172-184. http://www.paleoanthro.org/journal/volumes/2016/ Today I gave a talk for my colleagues at IPHES to outline aspects of the IDENTITIES Project (H2020-MSCA-IF-2016 No. 749188). The talk was a very useful opportunity for me to organize my thoughts, since the pace of data collection for the IDENTITIES Project is about to speed up.
I also discussed ongoing collaborative work on the taphonomy of some Neandertal fossils from Poland. The work is ongoing, so more will be said about this topic when the research is complete. |
John C. Willman
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