Cultures et Environnements. Préhistoire, Antiquité, Moyen Âge

from the Indus Valley. This process was likely stimulated at the onset of the current geological age, ~4.2 thousand years ago, by a widespread multicentury drought. In contrast to genome-wide admixture, mitochondrial DNA stasis supports that this introgression was male-driven, suggesting that selection of arid-adapted zebu bulls enhanced herd survival. This human-mediated migration of zebu-derived genetics has continued through millennia, altering tropical herding on each continent.

Mass spectrometry (MS) is an essential tool in the field of biomolecular archeology to characterize amorphous organic residues preserved in ancient ceramic vessels. Animal fats of various nature and origin, namely subcutaneous fats of cattle, sheep, goats, pigs, horses, and also of dairy products, are those most commonly identified in organic residues in archeological pottery. Fats and oils of marine origin have also been revealed. Since the first applications of MS coupled with gas chromatography (GC) in archeology at the end of 1980s, several developments have occurred, including isotopic determinations by GC coupled to isotope ratio MS and identification of triacylglycerols (TAGs) structure by soft ionization techniques (ESI and APCI). The combination of these methods provides invaluable insights into the strategies of exploitation of animal products in prehistory. In this review, I focus on the analytical strategies based upon MS that allow elucidation of the structure of biomolecular constituents and determination of their isotopic values to identify the nature of animal fat components preserved in highly complex and degraded archeological matrices.

= 98) (7000-3000 BCE). Using the genetic substructure observed in European hunter-gatherers, we characterize diverse patterns of admixture in different regions, consistent with both routes of expansion. Early western European farmers show a higher proportion of distinctly western hunter-gatherer ancestry compared to central/southeastern farmers. Our data highlight the complexity of the biological interactions during the Neolithic expansion by revealing major regional variations.

Archaeological evidence indicates that pig domestication had begun by ∼10,500 y before the present (BP) in the Near East, and mitochondrial DNA (mtDNA) suggests that pigs arrived in Europe alongside farmers ∼8,500 y BP. A few thousand years after the introduction of Near Eastern pigs into Europe, however, their characteristic mtDNA signature disappeared and was replaced by haplotypes associated with European wild boars. This turnover could be accounted for by substantial gene flow from local European wild boars, although it is also possible that European wild boars were domesticated independently without any genetic contribution from the Near East. To test these hypotheses, we obtained mtDNA sequences from 2,099 modern and ancient pig samples and 63 nuclear ancient genomes from Near Eastern and European pigs. Our analyses revealed that European domestic pigs dating from 7,100 to 6,000 y BP possessed both Near Eastern and European nuclear ancestry, while later pigs possessed no more than 4% Near Eastern ancestry, indicating that gene flow from European wild boars resulted in a near-complete disappearance of Near East ancestry. In addition, we demonstrate that a variant at a locus encoding black coat color likely originated in the Near East and persisted in European pigs. Altogether, our results indicate that while pigs were not independently domesticated in Europe, the vast majority of human-mediated selection over the past 5,000 y focused on the genomic fraction derived from the European wild boars, and not on the fraction that was selected by early Neolithic farmers over the first 2,500 y of the domestication process.

International audience

A high-resolution sedimentological and geochemical study was performed on a 20 m long core from the alpine Lake Anterne (2063 m a.s.l., NW French Alps) spanning the last 10 ka. Sedimentation is mainly of minerogenic origin. The organic matter quantity (TOC%) as well as its quality (hydrogen (HI) and oxygen (OI) indices) both indicate the progressive onset and subsequent stabilization of vegetation cover in the catchment from 9950 to 5550 cal. BP. During this phase, the pedogenic process of carbonate dissolution is marked by a decrease in the calcium content in the sediment record. Between 7850 and 5550 cal. BP, very low manganese concentrations suggest anoxic conditions in the bottom-water of Lake Anterne. These are caused by a relatively high organic matter (terrestrial and lacustrine) content, a low flood frequency and longer summer stratification triggered by warmer conditions. From 5550 cal. BP, a decrease in TOC, stabilization of HI and higher sedimentation rates together reflect increased erosion rates of leptosols and developed soils, probably due to a colder and wetter climate. Then, three periods of important soil destabilization are marked by an increased frequency and thickness of flood deposits during the Bronze Age and by increases in topsoil erosion relative to leptosols (HI increases) during the late Iron Age/Roman period and the Medieval periods. These periods are also characterized by higher sedimentation rates. According to palynological data, human impact (deforestation and/or pasturing activity) probably triggered these periods of increased soil erosion.

La formation de Nachukui, dans l'Ouest-Turkana (Nord Kenya) est riche de nombreux sites archéologiques plio-pléistocènes. Les recherches menées par le West Turkana Archaeological Project permettent, dans une fenêtre chronologique allant de 2,35 Ma à 0,7 Ma, de documenter la diversité des techniques et les capacités cognitives qui les sous-tendent et, plus largement, l'évolution comportementale des hominidés sur plus d'un million et demi d'années, dans un cadre chronostratigraphique et paléoenvironnemental reconstitué au plus précis. Ces travaux s'appuient sur des fouilles menées entre 1997 et 2001 dans trois complexes de sites de la formation appartenant au Pliocène final et au début du Pléistocène.

Hepatitis B virus (HBV) has been infecting humans for millennia and remains a global health problem, but its past diversity and dispersal routes are largely unknown. We generated HBV genomic data from 137 Eurasians and Native Americans dated between ~10,500 and ~400 years ago. We date the most recent common ancestor of all HBV lineages to between ~20,000 and 12,000 years ago, with the virus present in European and South American hunter-gatherers during the early Holocene. After the European Neolithic transition, Mesolithic HBV strains were replaced by a lineage likely disseminated by early farmers that prevailed throughout western Eurasia for ~4000 years, declining around the end of the 2nd millennium BCE. The only remnant of this prehistoric HBV diversity is the rare genotype G, which appears to have reemerged during the HIV pandemic.

Genomic studies conducted on ancient individuals across Europe have revealed how migrations have contributed to its present genetic landscape, but the territory of present-day France has yet to be connected to the broader European picture. We generated a large dataset comprising the complete mitochondrial genomes, Y-chromosome markers, and genotypes of a number of nuclear loci of interest of 243 individuals sampled across present-day France over a period spanning 7,000 y, complemented with a partially overlapping dataset of 58 low-coverage genomes. This panel provides a high-resolution transect of the dynamics of maternal and paternal lineages in France as well as of autosomal genotypes. Parental lineages and genomic data both revealed demographic patterns in France for the Neolithic and Bronze Age transitions consistent with neighboring regions, first with a migration wave of Anatolian farmers followed by varying degrees of admixture with autochthonous hunter-gatherers, and then substantial gene flow from individuals deriving part of their ancestry from the Pontic steppe at the onset of the Bronze Age. Our data have also highlighted the persistence of Magdalenian-associated ancestry in hunter-gatherer populations outside of Spain and thus provide arguments for an expansion of these populations at the end of the Paleolithic Period more northerly than what has been described so far. Finally, no major demographic changes were detected during the transition between the Bronze and Iron Ages.

A combination of elemental, functional and molecular analyses performed on amorphous organic residues dating from the Iron Age was developed in order to identify these remains and to understand their relationship with ceramic vessels in which some of them were found. These analyses made it possible to distinguish between ceramic vessels used for the production or storage of adhesive materials, mainly birch bark tar, and those dedicated to the preparation of culinary commodities, which contained animal fats. The organization of the production of adhesives is described and the addition of beeswax to birch bark tar is reported for the first time. The use of birch bark tar for coating ceramic vessels is also discussed.

Abstract The reliability of phytolith assemblage analysis for characterizing Mediterranean vegetation is investigated in this study. Phytolith assemblages are extracted from modern and buried Holocene soils from the middle Rhône valley (France). The relation between modern phytolith assemblages and the surrounding vegetation, as well as between fossil assemblages and contemporaneous vegetation, already reconstructed through other proxies, is discussed. We demonstrate that the main northwestern Mediterranean biomes are well distinguished by soil phytolith assemblage analysis. In particular, the density of pine and nonconiferous trees (densities expressed relatively to the grass cover) and the overall degree of opening of the vegetation appear well recorded by three phytolith indexes. North Mediterranean vegetation changes during the Holocene period, mainly tree line shifts, pine wood development and deforestation are poorly documented, due to the scarcity of proxy-preserving sites. Phytolith assemblage analysis of soils, buried soils, and sediments appears to be a promising technique to fill this gap.

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BACKGROUND AND OBJECTIVE: To evaluate the impact of a solid nutritional supplement on the weight gain of institutionalised older adults>70 years with protein-energy malnutrition. The innovation of these high-protein and high-energy cookies was the texture adapted to edentulous patients (Protibis®, Solidages, France). DESIGN: An open, multicentre, randomised controlled trial. SETTING: Seven nursing homes. PARTICIPANTS: One hundred and seventy-five malnourished older adults, aged 86±8 years. INTERVENTION: All participants received the standard institutional diet. In addition, Intervention group participants received eight cookies daily (11.5 g protein; 244 kcal) for 6 weeks (w0-w6). MEASUREMENTS: Five visits (w-4, w0, w6, w10 and w18). MAIN OUTCOME: Percentage of weight gain from w0 to w6 (body mass in kg). SECONDARY OUTCOMES: Appetite, rated using a numerical scale (0: no appetite to 10: extremely good appetite); current episodes of pressure ulcers and diarrhea. RESULTS: Average weight increased in Intervention group (n=88) compared with Control group (n=87) without cookies supplementation (+1.6 versus -0.7%, P=0.038). Weight gain persisted 1 month (+3.0 versus -0.2%, P=0.025) and 3 months after the end of cookies consumption (+3.9 versus -0.9%, P=0.003), with diarrhea reduction (P=0.027). There was a synergistic effect with liquid/creamy dietary supplements. Subgroup analysis confirmed the positive impact of cookies supplementation alone on weight increase (P=0.024), appetite increase (P=0.009) and pressure ulcers reduction (P=0.031). CONCLUSION: The trial suggested that, to fight against anorexia, the stimulation of touch (finger food; chewing, even on edentulous gums) and hearing (intra-oral sounds) could be valuable alternatives to sight, smell and taste alterations.

Au sein du Middle Stone Age (MSA) sud-africain, les techno-complexes Stillbay et Howiesons Poort montrent des traits comportementaux annonciateurs du caractère moderne des industries qui leur ont succédé. Toutefois, la position chronologique relative de ces techno-complexes demeurait imprécise en raison de datations radiométriques trop rares et en l'absence d'une archéoséquence pertinente.Les nouvelles fouilles entreprises en 1998 dans l'abri sous-roche de Diepkloof (province du Cap) ont permis de mettre au jour une stratigraphie, dans laquelle le faciès Stillbay est sous-jacent au faciès Howiesson Poort. En outre, ce dernier faciès a été daté par thermoluminescence d'un âge compris entre 55 et 65 ka.

Chemical and structural similarities between poorly preserved charcoal and its contaminants, as well as low radiocarbon concentrations in old samples, complicate 14 C age determinations. Here, we characterize 4 fossil charcoal samples from the late Middle Paleolithic and early Upper Paleolithic strata of Kebara Cave, Israel, with respect to the structural and chemical changes that occur when they are subjected to the acid-base-acid (ABA) treatment. Differential thermal analysis and TEM show that acid treatment disrupts the structure, whereas alkali treatment results in the reformation of molecular aggregates. The major changes are ascribed to the formation of salt bridges at high pH and the disruption of the graphite-like crystallites at low pH. Weight losses during the treatments are consistently greater for older samples, implying that they are less well preserved. Based on the changes observed in vitro due to pH fluctuations, various methods for removing contamination, as well as a mechanism for preferential preservation of charcoal in nature, are proposed.

Brain strokes are one of the leading causes of disability and mortality in adults in developed countries. Ischemic stroke (85% of total cases) and hemorrhagic stroke (15%) must be treated with opposing therapies, and thus, the nature of the stroke must be determined quickly in order to apply the appropriate treatment. Recent studies in biomedical imaging have shown that strokes produce variations in the complex electric permittivity of brain tissues, which can be detected by means of microwave tomography. Here, we present some synthetic results obtained with an experimental microwave tomography-based portable system for the early detection and monitoring of brain strokes. The determination of electric permittivity first requires the solution of a coupled forward-inverse problem. We make use of massive parallel computation from domain decomposition method and regularization techniques for optimization methods. Synthetic data are obtained with electromagnetic simulations corrupted by noise, which have been derived from measurements errors of the experimental imaging system. Results demonstrate the possibility to detect hemorrhagic strokes with microwave systems when applying the proposed reconstruction algorithm with edge preserving regularization.

Pech de l'Az IV (Dordogne, France) is a collapsed cave with an approximately three meter sequence of wellpreserved Mousterian assemblages. At the base of the sequence, resting on bedrock, is a ~50cm thick layer (Layer 8) of dark, primarily anthropogenic sediments that show unambiguous evidence of Neandertal use of fire dating to the time of OIS 5c. The faunal assemblage, which suggests a temperate, wooded environment, has evidence for the exploitation of some small game, and provides possible evidence for some non-subsistence related activities. The stone tool assemblage is characterized by the use of Levallois technology and, among the retouched tools, scrapers are predominant. Raw materials were primarily local and the complete reduction sequence is present in the assemblage with no evidence for import or export of prepared elements. Because of the state of preservation of all aspects of this layer, it represents one of the clearest examples of human management of fire in the European Middle Paleolithic.

The hypothesis of bone being used as fuel is put forward to explain the abundance of burnt bones inside bone assemblages. This utilization is often compared with the lack of wood in the surroundings of sites. Yet, utilization of bone seems to be attested all along the Upper Palaeolithic aside ambient climatic conditions. As a matter of fact, some of the occupations are contemporaneous with temparate phases when palaeoenvironmental data show the existence of a forest environment. Therefore, it is possible to consider a well-reasoned utilization of this fuel, regardless the available ligneous biomass but deeply connected to local household activities. Only the knowledge of the combustible properties of bone may bring part of an answer about this preferential utilization as a hypothesis, according to the function of the hearth. A vast experimental programme is undertaken for this purpose. The experiments on more than 120 kg of bone were carried out along with intrinsic and extrinsic parameters which govern combustion. The results allow us to determine precisely the bone combustible properties along with their histological nature, the level of humidity and the fractures. We can also distinguish bone assemblages strictly being used as fuel from those having fortuitous combustion marks. Therefore, the properties of bone and wood can be paralleled and so it is possible to define more clearly the purpose of a preferential utilization of bone and to propose a model of fuel management appropriate to energy needs of each group.

Bedding of grass and ashes The Border Cave site in the KwaZulu-Natal region of South Africa has been a rich source of archaeological knowledge about Stone Age humans because of its well-preserved stratigraphic record. Wadley et al. now report the discovery of grass bedding in Border Cave, dated to approximately 200,000 years ago. The bedding, identified with a range of microscopic and spectroscopic techniques, was mingled with layers of ash. It also incorporated debris from lithics, burned bone, and rounded ochre grains, all of which were of clear anthropogenic origin. The authors speculate that the ash may have been deliberately used in bedding to inhibit the movement of ticks and other arthropod irritants. These discoveries extend the record of deliberate construction of plant bedding by at least 100,000 years. Science , this issue p. 863

L'étude du Paléolithique moyen, souvent décrit comme<br />une période de stabilité, voire de monotonie en termes<br />d'innovations techniques, révèle en fait un foisonnement<br />de savoirs et de moyens techniques dont l'ampleur ne cesse<br />de croître au fur et à mesure que les recherches progressent<br />et s'intensifient. Cette diversité apporte un éclairage<br />nouveau, tant sur l'éventail des compétences et habiletés<br />techniques des populations néandertaliennes que sur les<br />processus qui ont pu conduire aux changements perceptibles<br />à la fin du Paléolithique moyen, et contemporains<br />de l'arrivée des Hommes anatomiquement modernes en<br />Europe occidentale.