Technological responses of Neanderthals to macroclimatic variations (240,000-40,000 BP).

Using a database of 499 archaeological assemblages from 332 sites in Europe, we statistically test a model of the economic reactivity of the hunter-gatherer production system to climatic variations. This model predicts an increase in the diversity of lithic tools during harsh cold periods, in order to maintain carrying capacity, and a reduction during favorable climatic periods. Diversity was measured from the variations in flint tool distributions in traditional Bordes typological categories, using Shannon's derived diversity index (D). Reactivity was measured in 190 archaeological assemblages from 103 sites of the Middle Paleolithic in Europe (mainly France). The Neanderthals show technological inertia in the development and use of lithic tools for 200,000 years, despite the four cool to cold macroclimatic periods they experienced.

Cementochronology, to cut or not to cut?

One of the continuing problems in paleopathology and paleoepidemiology is an inability to accurately age adult skeletons. Accurate age estimations are critical to the proper evaluation of population health and are necessary in circumventing certain aspects of the osteological paradox. Cementochronology is most likely the only age indicator in anthropology that directly considers a continuously growing tissue and does not require either complex statistical manipulations or the use of a reference population. The major issues and recent advances linked to this technique are reviewed for its successful implementation. This review is a partial outcome of an international research program initiated in 2010 to develop and expand cementochronology. Because cementochronology is a reasonably straightforward histological protocol, it can be implemented in less than 24h for one tooth at a relatively low cost. The only aspect of cementochronology that requires extensive previous experience is the counting of increments. These unique aspects largely justify the regular implementation of cementochronology in paleoepidemiology and paleopathology in the confident exploration of "population health" issues and demographic inferences.

The leprosarium of Saint-Thomas d'Aizier: The cementochronological proof of the medieval decline of Hansen disease in Europe?

This study compares the adult survivorship profiles of people interred in the Saint-Thomas d'Aizier leprosarium, estimated by cementochronology, to eight archaeological series in northern France dated from Late Antiquity to the Late Middle Ages, periods of significant visibility for Hansen's disease (leprosy). The goals are to understand the impact of leprosy on various social groups and to explore the cause of leprosy's decline by analyzing male and female fertility. Survival rates differed between medieval leprosy-free sites and the Saint-Thomas d'Aizier leprosarium, although this difference was statistically significant only for the female leprosarium sample. The selective female frailty, a consequence of social exclusion and the collapse of the quality of life, combined with the infertility of lepromatous couples, offer a multi-causal explanation to the end of the expansion and then decline of leprosy in southern and western European countries.

When the world's population took off: the springboard of the Neolithic Demographic Transition.

During the economic transition from foraging to farming, the signal of a major demographic shift can be observed in cemetery data of world archaeological sequences. This signal is characterized by an abrupt increase in the proportion of juvenile skeletons and is interpreted as the signature of a major demographic shift in human history, known as the Neolithic Demographic Transition (NDT). This expresses an increase in the input into the age pyramids of the corresponding living populations with an estimated increase in the total fertility rate of two births per woman. The unprecedented demographic masses that the NDT rapidly brought into play make this one of the fundamental structural processes of human history.

Classification of ancient mammal individuals using dental pulp MALDI-TOF MS peptide profiling.

BACKGROUND: The classification of ancient animal corpses at the species level remains a challenging task for forensic scientists and anthropologists. Severe damage and mixed, tiny pieces originating from several skeletons may render morphological classification virtually impossible. Standard approaches are based on sequencing mitochondrial and nuclear targets. METHODOLOGY/PRINCIPAL FINDINGS: We present a method that can accurately classify mammalian species using dental pulp and mass spectrometry peptide profiling. Our work was organized into three successive steps. First, after extracting proteins from the dental pulp collected from 37 modern individuals representing 13 mammalian species, trypsin-digested peptides were used for matrix-assisted laser desorption/ionization time-of-flight mass spectrometry analysis. The resulting peptide profiles accurately classified every individual at the species level in agreement with parallel cytochrome b gene sequencing gold standard. Second, using a 279-modern spectrum database, we blindly classified 33 of 37 teeth collected in 37 modern individuals (89.1%). Third, we classified 10 of 18 teeth (56%) collected in 15 ancient individuals representing five mammal species including human, from five burial sites dating back 8,500 years. Further comparison with an upgraded database comprising ancient specimen profiles yielded 100% classification in ancient teeth. Peptide sequencing yield 4 and 16 different non-keratin proteins including collagen (alpha-1 type I and alpha-2 type I) in human ancient and modern dental pulp, respectively. CONCLUSIONS/SIGNIFICANCE: Mass spectrometry peptide profiling of the dental pulp is a new approach that can be added to the arsenal of species classification tools for forensics and anthropology as a complementary method to DNA sequencing. The dental pulp is a new source for collagen and other proteins for the species classification of modern and ancient mammal individuals.