Arkadiusz Sołtysiak

Sequencing ancient calcified dental plaque shows changes in oral microbiota with dietary shifts of the Neolithic and Industrial revolutions

The importance of commensal microbes for human health is increasingly recognized, yet the impacts of evolutionary changes in human diet and culture on commensal microbiota remain almost unknown. Two of the greatest dietary shifts in human evolution involved the adoption of carbohydrate-rich Neolithic (farming) diets (beginning ∼10,000 years before the present) and the more recent advent of industrially processed flour and sugar (in ∼1850). Here, we show that calcified dental plaque (dental calculus) on ancient teeth preserves a detailed genetic record throughout this period. Data from 34 early European skeletons indicate that the transition from hunter-gatherer to farming shifted the oral microbial community to a disease-associated configuration. The composition of oral microbiota remained unexpectedly constant between Neolithic and medieval times, after which (the now ubiquitous) cariogenic bacteria became dominant, apparently during the Industrial Revolution. Modern oral microbiotic ecosystems are markedly less diverse than historic populations, which might be contributing to chronic oral (and other) disease in postindustrial lifestyles.

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.

Late Chalcolithic mass graves at Tell Brak, Syria, and violent conflict during the growth of early city-states

Abstract Excavations and surveys carried out from the mid-1990s through 2009 at Tell Brak, northeast Syria, have focused on reconstructing the socioeconomic complexity and physical growth of one of northern Mesopotamias earliest urban settlements. The recent discovery of several mass graves on the edge of the city, created at an important threshold in its physical expansion (ca. 3800–3600 B.C.), adds to a longstanding debate about the connection between the growth of early city-states and violent conflict. These graves, with their population of as many as several hundred primarily sub-adults and young adults, are interpreted as the result of large-scale violent events and may provide evidence for the post-mortem treatment of enemies. They offer a strong counterpoint to the dominant reconstruction of a peaceful prehistory in the region.

Excavations at Tell Brak 2006-2007

Excavations at Tell Brak in 2006–7 explored two key episodes in Mesopotamian political and social history, developing early social complexity in the fifth to fourth millennia BC and the shift from territorial state to early empire in the second millennium BC. Late Chalcolithic complexity is represented in Area TW on the main mound and at the outlying sub-mound of Tell Majnuna, while investigation of the Old Babylonian to Mitanni state-to-empire transition involved excavation in Areas HH and HN (Fig. 1). Both sets of excavations tie into our exploration of larger issues of the creation and maturation of past urban landscapes, for which Tell Brak provides a great depth of data. We would like once again to express our warmest gratitude to Dr Bassam Jamous, Director General of Antiquities and Museums, to Dr Michel Al-Maqdissi, Director of Excavations, to all their staff in Damascus, and to Sd Abdul Messih Baghdo, Director of the Antiquities Office in Hasseke, for their constant and friendly support. Financial support for the excavations was generously provided by the British School of Archaeology in Iraq, the McDonald Institute for Archaeological Research, Cambridge, the National Geographic Committee for Research and Exploration (2006), the Society of Antiquaries of London (2007), Newnham College, Cambridge and the University of Cambridge. We are extremely grateful to all those who have made this research possible.

Isotope evidence for agricultural extensification reveals how the world's first cities were fed

This study sheds light on the agricultural economy that underpinned the emergence of the first urban centres in northern Mesopotamia. Using δ13C and δ15N values of crop remains from the sites of Tell Sabi Abyad, Tell Zeidan, Hamoukar, Tell Brak and Tell Leilan (6500–2000 cal bc), we reveal that labour-intensive practices such as manuring/middening and water management formed an integral part of the agricultural strategy from the seventh millennium bc. Increased agricultural production to support growing urban populations was achieved by cultivation of larger areas of land, entailing lower manure/midden inputs per unit area—extensification. Our findings paint a nuanced picture of the role of agricultural production in new forms of political centralization. The shift towards lower-input farming most plausibly developed gradually at a household level, but the increased importance of land-based wealth constituted a key potential source of political power, providing the possibility for greater bureaucratic control and contributing to the wider societal changes that accompanied urbanization.

Equids and an acrobat : closure rituals at Tell Brak

Deposits of human and animal bodies in a monumental Akkadian building at Tell Brak (ancient Nagar) superficially suggest random killing and disposal. But here the authors produce evidence that these represent the deliberate sacrifice of valued creatures. Among the human remains were those argued to represent a specialist acrobat, while the donkey remains reflect the association of the building with the breeding of the much-debated onager-donkey hybrid that preceded the horse.

Population history of the middle Euphrates valley: dental non-metric traits at Tell Ashara, Tell Masaikh and Jebel Mashtale, Syria.

Fifty-nine dental non-metric traits were scored using Arizona State University Dental Anthropology System on a sample of teeth from 350 human skeletons excavated at three sites in the lower middle Euphrates valley. The dataset was divided into six chronological subsets: Early Bronze Age, Middle Bronze Age, Early Iron Age with Neo-Assyrian period, Classical/Late Antiquity, Early Islamic (Umayyad and Abbasid) period and Modern period. The matrix of Mean Measure of Divergence values exhibited temporal homogeneity of the sample with only dental non-metric trait scores in the Modern subset differing significantly from most other subsets. Such a result suggests that no major gene flow occurred in the middle Euphrates valley between the 3rd millennium BCE and the early 2nd millennium CE. Only after the Mongolian invasion and large depopulation of northern Mesopotamia in the 13th century CE a major population change occurred when the area was taken over in the 17th century by Bedouin tribes from the Arabian Peninsula.

Comment: Low dental caries rate in Neandertals: The result of diet or the oral flora composition?

Dental caries is an infectious disease caused by oral acidophilic bacteria feeding on fermentable sugars, e.g. Streptococcus mutans. The frequency of dental caries in Neandertals was very low. This was usually explained as the result of a low-sugar diet. Recent research, however, revealed some regional differences between European and Near Eastern Neandertals, with the latter consuming considerable amounts of plants including highly cariogenic dates. This discovery, compared with the results of research on genetic diversity of S. mutans, may suggest that this species, and perhaps other most virulent species, were absent in the oral flora of Neandertals.

Plant microfossils in human dental calculus from Nemrik 9, a Pre-Pottery Neolithic site in Northern Iraq

Samples of dental calculus were taken from 11 human individuals buried at Nemrik 9, a Pre-Pottery Neolithic site in Northern Iraq. All of them represented the time span of ca. 9100–8600 bp. In total, 95 microfossils were retrieved from these samples, including 70 phytoliths, 9 starch granules or clusters of starch, 3 pollens, and 1 xylem fragment. Most microfossils could be attributed to C3 cool season cereals, most likely wheat and barley, which is consistent with previous knowledge about the composition of crops in early farming communities living in the Fertile Crescent. In addition, three phytoliths and one starch granule typical of C4 warm season grasses were recovered including one subangular and faceted starch granule, which might derive from a native grass, but is not diagnostic of any genus. Prior to assigning diagnostic status to this starch, exhaustive reference work on native grass seeds is necessary. The presence of one Phragmites phytolith suggests non-alimentary processing of reeds using teeth or perhaps using the stem of this grass as a toothbrush or toothpick.

Estimation of collagen presence in dry bone using combined X-ray and neutron radiography

Thermal neutron radiography and X-ray radiography are characterised by different penetration depths in various materials, for example in collagen and hydroxyapatite, two major components of bone. Neutron radiography penetrates hydroxyapatite easier than collagen and, conversely, in X-ray radiography attenuation is higher in hydroxyapatite than in collagen. This effect allows estimation of collagen presence in dry bone. In our study we show that differences between the two imaging methods are sufficient to produce significant results when bone areas with higher and lower content of collagen are being compared.