Neanderthal behaviour, diet, and disease inferred from ancient DNA in dental calculus.

Recent genomic data have revealed multiple interactions between Neanderthals and modern humans, but there is currently little genetic evidence regarding Neanderthal behaviour, diet, or disease. Here we describe the shotgun-sequencing of ancient DNA from five specimens of Neanderthal calcified dental plaque (calculus) and the characterization of regional differences in Neanderthal ecology. At Spy cave, Belgium, Neanderthal diet was heavily meat based and included woolly rhinoceros and wild sheep (mouflon), characteristic of a steppe environment. In contrast, no meat was detected in the diet of Neanderthals from El Sidrón cave, Spain, and dietary components of mushrooms, pine nuts, and moss reflected forest gathering. Differences in diet were also linked to an overall shift in the oral bacterial community (microbiota) and suggested that meat consumption contributed to substantial variation within Neanderthal microbiota. Evidence for self-medication was detected in an El Sidrón Neanderthal with a dental abscess and a chronic gastrointestinal pathogen (Enterocytozoon bieneusi). Metagenomic data from this individual also contained a nearly complete genome of the archaeal commensal Methanobrevibacter oralis (10.2× depth of coverage)-the oldest draft microbial genome generated to date, at around 48,000 years old. DNA preserved within dental calculus represents a notable source of information about the behaviour and health of ancient hominin specimens, as well as a unique system that is useful for the study of long-term microbial evolution.

Dental pulp calcifications in prehistoric and historical skeletal remains.

BACKGROUND: The prevalence of hard tissue formations in the dental pulp varies considerably. Beside ageing processes and irritations of the dental pulp, etiological associations with cardiovascular disease and dietary habits have been discussed, which are of particular research interest. The aim of this pilot study is to provide new insights on structural and etiological factors involved in the development of pulp calcifications by investigating skeletal remains from different (pre)historic periods. METHODS: The jaws of 46 skeletons excavated in central Germany, were examined for the presence of pulp stones using digital volume tomography (DVT). A total of 1122 teeth were examined with all tooth types considered. To obtain information about the three-dimensional structure of pulp calcifications, micro-CT images were taken. Thin sections of three molars were histologically analysed. Potential dietary effects were studied by analysing stable isotope ratios of nitrogen (δ15N) in bone samples collected from each individual. RESULTS: The analysis indicates that pulp stones affect molars in particular and increase slightly with age and dental wear. The micro-CT scans and the histological analysis show that the structures are much more complex than presumed on the basis of DVT imaging. Individuals with lower δ15N-isotope values and thus with a potentially lower proportion of animal protein in their diet appear to be less affected by pulp stones. CONCLUSION: When comparing between archaeological and recent data, DVT analysis provides qualitatively comparable results. Micro-CT and histological images illustrate the excellent preservation of pulp calcifications and their complex structure. Differences in prevalence rates and δ15N-isotope values of Neolithic and historical individuals support the assumption that dietary habits and living conditions could have an influence on the development of pulp calcifications. Due to the small sample size these results require further validation.