2018 by Jean-Jacques Hublin
Here we report Sr and Zn isotope ratios of teeth of medieval to early modern Breton people a popu... more Here we report Sr and Zn isotope ratios of teeth of medieval to early modern Breton people a population whose diet is known from historical, archeological and collagen isotope data. Most of the population, buried in the Dominican convent of Rennes, France, consists of parliamentary nobles, wealthy commoners and ecclesiastics, who had a diet rich in animal products. Our aim is to assess how the Zn isotope ratios of their teeth compare to those of other French historical populations previously studied, which were characterized by cereal-based diets, and those of modern French individuals, who daily eat animal products. We describe a clear offset (∼0.35‰) between local and non-local human individuals in Zn isotope ratios. The δ 66 Zn tooth values of local individuals overlap that of modern French people, and are lower than those of local carnivores. Non-local δ 66 Zn values are similar to those of historical individuals analyzed previously. We conclude the lower Zn isotope ratios of local humans relative to the associated fauna can be explained by the consumption of carnivorous fish and pork, in agreement with historical, zooarchaeological and collagen (C, N, S) isotope data. Zn isotopes could therefore be a tracer of fish and/or substantial meat consumption in ancient populations. The origin of Zn isotopic variability in human tissues remained unknown until Van Heghe et al. (2012) 1 , reported the strong impact of meat and fish consumption on blood Zn isotope ratios (66 Zn/ 64 Zn expressed as δ 66 Zn values), a preliminary conclusion quickly confirmed by Costas-Rodriguez et al. (2014) 2. A parallel study on African food webs did not quantify the exact relationship between diet and bone Zn isotope ratios 3 , however by focusing on a much smaller geographical area, the sensitivity of Zn isotopes to diet was demonstrated 4 : Zn isotope ratios of bones and teeth clearly differ between carnivores and herbivores, with carnivores exhibiting the lowest ratios. The dependence of Zn isotope ratios on trophic level has also been confirmed in a marine ecosystem 5. The isotopic composition of Zn in animal tissues is controlled by two dietary factors: the isotopic fractionation that occurs during intestinal absorption and the Zn isotope ratios of the food products. Dietary Zn mainly comes from animal products, notably because Zn-and preferentially its lighter isotopes-from plants tends to precipitate with the phytates in the gastro intestinal tract 6. This precipitation is likely to trigger isotopic fractionation inducing the preferential absorption of heavy Zn isotopes. Additionally, plant products usually have the most elevated δ 66 Zn values 2. As a consequence, herbivore tissues exhibit higher Zn isotope ratios compared to carnivore or omnivore tissues 3-5. Muscles are 66 Zn depleted relative to the average isotopic composition of the body and no isotope fractionation of Zn is expected during meat consumption 3. Carnivores therefore have lower δ 66 Zn values than their prey: the higher the trophic level of an animal is, the lower are the Zn isotope ratios of its body tissues 5. Zn isotope ratios of dental enamel from populations from different locations and historical periods were recently compared 7. The study highlighted a very surprising trend: the δ 66 Zn dental values of preindustrial
Objectives: Several studies have investigated potential functional signals in the trabecular stru... more Objectives: Several studies have investigated potential functional signals in the trabecular structure of the primate proximal humerus but with varied success. Here, we apply for the first time a "whole-epiphyses" approach to analysing trabecular bone in the humeral head with the aim of providing a more holistic interpretation of trabecular variation in relation to habitual locomotor or manipulative behaviors in several extant primates and Australopithecus africanus. Materials and methods: We use a "whole-epiphysis" methodology in comparison to the traditional volume of interest (VOI) approach to investigate variation in trabecular structure and joint loading in the proximal humerus of extant hominoids, Ateles and A. africanus (StW 328). Results: There are important differences in the quantification of trabecular parameters using a "whole-epiphysis" versus a VOI-based approach. Variation in trabecular structure across knuckle-walking African apes, suspensory taxa, and modern humans was generally consistent with predictions of load magnitude and inferred joint posture during habitual behaviors. Higher relative trabecular bone volume and more isotropic trabeculae in StW 328 suggest A. africanus may have still used its forelimbs for arboreal locomotion. Discussion: A whole-epiphysis approach to analysing trabecular structure of the proximal humerus can help distinguish functional signals of joint loading across extant primates and can provide novel insight into habitual behaviors of fossil hominins. K E Y W O R D S arboreal, cancellous bone, hominin, locomotion, upper limb
Mainland Southeast Asia is a key region to interpret modern human migrations; however, due to a s... more Mainland Southeast Asia is a key region to interpret modern human migrations; however, due to a scarcity of terrestrial proxies, environmental conditions are not well understood. This study focuses on the Tam Pà Ling cave site in northeast Laos, which contains the oldest evidence for modern humans in Indochina, dating back to MIS 4 (70 ± 8 ka). Snail remains of Camaena massiei found throughout the stratigraphic sequence contain a valuable oxygen and carbon isotope record of past local vegetation and humidity changes. Our data indicate that before the Last Glacial Maximum (LGM), northeast Laos was characterized by a humid climate and forested environments. With the onset of the LGM, a major climatic shift occurred, inducing a sharp decrease in precipitation and a significant decline in woodland habitats in favor of the expansion to more open landscapes. Only during the Holocene did forests return in northeast Laos, resembling present conditions. The first Homo sapiens arriving in Indochina therefore encountered landscapes dominated by woodlands with a minor proportion of open habitats.
Most of the Middle Palaeolithic evidence of Central Italy still lacks a reliable chrono-cultural ... more Most of the Middle Palaeolithic evidence of Central Italy still lacks a reliable chrono-cultural framework mainly due to research history. In this context Grotta dei Santi, a wide cave located on Monte Argentario, on the southern coast of Tuscany, is particularly relevant as it contains a very well preserved sequence including several Mousterian layers. Research carried out at this site in the last years (2007e2017) allowed for a preliminary estimation of its chronology based on a set of radiometric determinations which place the investigated sequence in the time interval between 50 and 40 ka BP. Alongside the chronological issue, this paper mainly focuses on the geoarchaeological and zooarchaeological (micro and macro fauna) studies carried out on the materials retrieved during the 2007e2014 excavation fieldworks. The results of these studies are consistent with those from the radiometric chronology. A state of art concerning the MIS3 Italian sites is also provided in order to highlight the key role Grotta dei Santi may play in the assessment of late Neandertals' behaviour within the framework of the Middle to Upper Palaeolithic transition of Central Italy.
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2018 by Jean-Jacques Hublin