Oliver E. Craig

Something fishy in the Neolithic? A re-evaluation of stable isotope analysis of Mesolithic and Neolithic coastal populations

The study of the proportions of stable isotopes of carbon and nitrogen which survive in ancient human and animal bones offers highly suggestive indications of ancient diets. Among the most remarkable results from such investigations is the dramatic change in diet which is thought to have occurred between the Mesolithic and the Neolithic when people turned from maritime to terrestrial food, from fish to meat and vegetables. The three contributions which follow challenge, modify, enhance or reflect on this model. In a pivotal critique of the evidence from Britain and Denmark, Milner et al. present a range of explanations for the signals of a maritime or terrestrial emphasis in diet and conclude that the change need not have been either rapid or total. Liden et al. show that, in southern Sweden, the preferences for fish over meat were related less to period or culture, but (reasonably enough) to location: fish-eaters live by the sea. Finally Robert Hedges takes up the question of partial marine diets and how to detect them, developing the idea that marine diets might give a fainter signal in people who were only getting small amounts of protein. Perhaps there were many such people in the new order of the Neolithic …

Determining the human origin of fragments of burnt bone: a comparative study of histological, immunological and DNA techniques.

In situations where badly burnt fragments of bone are found, identification of their human or non-human origin may be impossible by gross morphology alone and other techniques have to be employed. In order to determine whether histological methods were redundant and should be superseded by biomolecular analyses, small fragments of artificially burnt bone (human and non-human) were examined by quantitative and standard light microscopy, and the findings compared with newer biomolecular analyses based on identifying specific human albumin by ELISA and amplifying human mitochondrial DNA by PCR. For quantitative microscopy, reference data were first created using burnt bones from 15 human and 20 common domestic and farm animals. Measured osteon and Haversian canal parameters were analysed using multivariate statistical methods. Highly significant differences were found between values for human and non-human bone, and a canonical discriminant function equation was derived, giving a predicted correct classification of 79%. For the main study, samples of cortical bone were taken from three fresh cadavers, six human skeletons and ten freshly slaughtered animals and burnt by exposure to temperatures ranging from 800 to 1200 degrees C; charred fragments of human cortical bone from two forensic cases were also tested. Quantitative microscopy and canonical discriminant function gave the correct origin of every sample. Standard microscopy falsely assigned burnt bone from one human skeleton and one forensic case to a non-human source, but otherwise gave correct results. Human albumin was identified in five individuals, including one of the forensic cases, but mitochondrial DNA could not be amplified from any of the human bone. No false positive test results were seen with either biomolecular method; and human albumin and mitochondrial DNA were correctly identified in all unburnt control specimens. It was concluded that histological methods were not redundant and that quantitative microscopy provided an accurate and consistent means of determining the human or non-human origin of burnt bone and was more reliable than standard microscopy or the newer immunological and DNA techniques tested here.

Earliest evidence for the use of pottery

Pottery was a hunter-gatherer innovation that first emerged in East Asia between 20,000 and 12,000 calibrated years before present (cal bp), towards the end of the Late Pleistocene epoch, a period of time when humans were adjusting to changing climates and new environments. Ceramic container technologies were one of a range of late glacial adaptations that were pivotal to structuring subsequent cultural trajectories in different regions of the world, but the reasons for their emergence and widespread uptake are poorly understood. The first ceramic containers must have provided prehistoric hunter-gatherers with attractive new strategies for processing and consuming foodstuffs, but virtually nothing is known of how early pots were used. Here we report the chemical analysis of food residues associated with Late Pleistocene pottery, focusing on one of the best-studied prehistoric ceramic sequences in the world, the Japanese Jōmon. We demonstrate that lipids can be recovered reliably from charred surface deposits adhering to pottery dating from about 15,000 to 11,800 cal bp (the Incipient Jōmon period), the oldest pottery so far investigated, and that in most cases these organic compounds are unequivocally derived from processing freshwater and marine organisms. Stable isotope data support the lipid evidence and suggest that most of the 101 charred deposits analysed, from across the major islands of Japan, were derived from high-trophic-level aquatic food. Productive aquatic ecotones were heavily exploited by late glacial foragers, perhaps providing an initial impetus for investment in ceramic container technology, and paving the way for further intensification of pottery use by hunter-gatherers in the early Holocene epoch. Now that we have shown that it is possible to analyse organic residues from some of the world’s earliest ceramic vessels, the subsequent development of this critical technology can be clarified through further widespread testing of hunter-gatherer pottery from later periods.

Ancient lipids reveal continuity in culinary practices across the transition to agriculture in Northern Europe

Farming transformed societies globally. Yet, despite more than a century of research, there is little consensus on the speed or completeness of this fundamental change and, consequently, on its principal drivers. For Northern Europe, the debate has often centered on the rich archaeological record of the Western Baltic, but even here it is unclear how quickly or completely people abandoned wild terrestrial and marine resources after the introduction of domesticated plants and animals at ∼4000 calibrated years B.C. Ceramic containers are found ubiquitously on these sites and contain remarkably well-preserved lipids derived from the original use of the vessel. Reconstructing culinary practices from this ceramic record can contribute to longstanding debates concerning the origins of farming. Here we present data on the molecular and isotopic characteristics of lipids extracted from 133 ceramic vessels and 100 carbonized surface residues dating to immediately before and after the first evidence of domesticated animals and plants in the Western Baltic. The presence of specific lipid biomarkers, notably ω-(o-alkylphenyl)alkanoic acids, and the isotopic composition of individual n-alkanoic acids clearly show that a significant proportion (∼20%) of ceramic vessels with lipids preserved continued to be used for processing marine and freshwater resources across the transition to agriculture in this region. Although changes in pottery use are immediately evident, our data challenge the popular notions that economies were completely transformed with the arrival of farming and that Neolithic pottery was exclusively associated with produce from domesticated animals and plants.

COMPARISON OF THREE DNA EXTRACTION METHODS ON BONE AND BLOOD STAINS UP TO 43 YEARS OLD AND AMPLIFICATION OF THREE DIFFERENT GENE SEQUENCES

Extraction of amplifiable DNA-from degraded human material in the forensic context remains a problem, and maximization of yield and elimination of inhibitors of the Polymerase Chain Reaction (PCR) are important issues which rarely feature in comparative studies. The present work used PCR amplification of three DNA sequences (HLA DPB1, amelogenin and mitochondrial) to assess the efficiency of three methods for extracting DNA (sodium acetate, magnetic beads and glass-milk) from 32 skeletal samples and 25 blood stains up to 43 years old. The results, analyzed using multivariate statistics, confirmed that the extraction method was crucial to the subsequent detection of amplification products; the glass-milk protocol performed better than sodium acetate, which was better than magnetic beads. Successful amplification also depended on gene sequence, multiple copy mitochondrial sequences performing best; however, with the singly copy sequences, the longer HLA DPB1 (327 bp) being detected just as often as the shorter amelogenin (106/112 bp). Amplification products were obtained more frequently from blood stains than bone, perhaps reflecting differences inherent in the material, and from younger compared with older specimens, though plateauing seemed to occur after 10 years. PCR inhibitors were more frequent in sodium acetate extracts.

Stable isotope evidence for the consumption of millet and other plants in Bronze Age Italy.

Stable carbon and nitrogen isotope analysis was carried out on human and animal bones from four inland Early and Middle Bronze Age sites in Northern and Southern Italy. The main aims of the investigation were to explore the contribution of plant foods to the human diet and to examine any dietary differences between and within each of the sites. At two of the sites in Northern Italy, human and animal bones were significantly enriched in 13C. This finding was attributed to the consumption of domestic millets (Panicum miliaceum and/or Setaria italica), which are C4 pathway plants. Conversely, individuals from the two Bronze Age sites in Southern Italy were significantly depleted in 13C compared to those from the north. Here, millet was absent from the diet, and protein from C3 plants made a much greater dietary contribution than animal protein. This finding highlights the importance of cereal cultivation, most likely of wheat and barley, in the south of Italy during the Bronze Age. Overall, our results support the idea that the widespread cultivation of millet first occurred in Northern Italy, following its introduction from across the Alps in Central Europe. Finally, we found no significant differences in the stable isotope values between individuals at each site, when grouped by their sex or presence of grave goods. This leads to the conclusion that any status difference that may have existed is not reflected in the long-term dietary record, or at least not as measurable by stable isotope analysis.

DNA in ancient bone – Where is it located and how should we extract it?

Despite the widespread use of bones in ancient DNA (aDNA) studies, relatively little concrete information exists in regard to how the DNA in mineralised collagen degrades, or where it survives in the materials architecture. While, at the macrostructural level, physical exclusion of microbes and other external contaminants may be an important feature, and, at the ultrastructural level, the adsorption of DNA to hydroxyapatite and/or binding of DNA to Type I collagen may stabilise the DNA, the relative contribution of each, and what other factors may be relevant, are unclear. There is considerable variation in the quality of DNA retrieved from bones and teeth. This is in part due to various environmental factors such as temperature, proximity to free water or oxygen, pH, salt content, and exposure to radiation, all of which increase the rate of DNA decay. For example, bone specimens from sites at high latitudes usually yield better quality DNA than samples from temperate regions, which in turn yield better results than samples from tropical regions. However, this is not always the case, and rates of success of DNA recovery from apparently similar sites are often strikingly different. The question arises as to whether this may be due to post-collection preservation or just an artefact of the extraction methods used in these different studies? In an attempt to resolve these questions, we examine the efficacy of DNA extraction methods, and the quality and quantity of DNA recovered from both artificially degraded, and genuinely ancient, but well preserved, bones. In doing so we offer hypotheses relevant to the DNA degradation process itself, and to where and how the DNA is actually preserved in ancient bone.

Evidence for mummification in Bronze Age Britain

Ancient Egyptians are thought to have been the only people in the Old World who were practising mummification in the Bronze Age (c. 2200-700 BC). But now a remarkable series of finds from a remote Scottish island indicates that Ancient Britons were performing similar, if less elaborate, practices of bodily preservation. Evidence of mummification is usually limited to a narrow range of arid or frozen environments which are conducive to soft tissue preservation. Mike Parker Pearson and his team show that a combination of microstructural, contextual and AMS 14 C analysis of bone allows the identification of mummification in more temperate and wetter climates where soft tissues and fabrics do not normally survive. Skeletons from Cladh Hallan on South Uist, Western Isles, Scotland were buried several hundred years after death, and the skeletons provide evidence of post mortem manipulation of body parts. Perhaps these practices were widespread in mainland Britain during the Bronze Age.

Early Neolithic genomes from the eastern Fertile Crescent

Near Eastern genomes from Iran The genetic composition of populations in Europe changed during the Neolithic transition from hunting and gathering to farming. To better understand the origin of modern populations, Broushaki et al. sequenced ancient DNA from four individuals from the Zagros region of present-day Iran, representing the early Neolithic Fertile Crescent. These individuals unexpectedly were not ancestral to early European farmers, and their genetic structures did not contribute significantly to those of present-day Europeans. These data indicate that a parallel Neolithic transition probably resulted from structured farming populations across southwest Asia. Science, this issue p. 499 Neolithic people from the region of modern Iran are genetically distinct from early northwestern Anatolian and European farmers. We sequenced Early Neolithic genomes from the Zagros region of Iran (eastern Fertile Crescent), where some of the earliest evidence for farming is found, and identify a previously uncharacterized population that is neither ancestral to the first European farmers nor has contributed substantially to the ancestry of modern Europeans. These people are estimated to have separated from Early Neolithic farmers in Anatolia some 46,000 to 77,000 years ago and show affinities to modern-day Pakistani and Afghan populations, but particularly to Iranian Zoroastrians. We conclude that multiple, genetically differentiated hunter-gatherer populations adopted farming in southwestern Asia, that components of pre-Neolithic population structure were preserved as farming spread into neighboring regions, and that the Zagros region was the cradle of eastward expansion.

Direct evidence of milk consumption from ancient human dental calculus

Milk is a major food of global economic importance, and its consumption is regarded as a classic example of gene-culture evolution. Humans have exploited animal milk as a food resource for at least 8500 years, but the origins, spread, and scale of dairying remain poorly understood. Indirect lines of evidence, such as lipid isotopic ratios of pottery residues, faunal mortality profiles, and lactase persistence allele frequencies, provide a partial picture of this process; however, in order to understand how, where, and when humans consumed milk products, it is necessary to link evidence of consumption directly to individuals and their dairy livestock. Here we report the first direct evidence of milk consumption, the whey protein β-lactoglobulin (BLG), preserved in human dental calculus from the Bronze Age (ca. 3000 BCE) to the present day. Using protein tandem mass spectrometry, we demonstrate that BLG is a species-specific biomarker of dairy consumption, and we identify individuals consuming cattle, sheep, and goat milk products in the archaeological record. We then apply this method to human dental calculus from Greenlands medieval Norse colonies, and report a decline of this biomarker leading up to the abandonment of the Norse Greenland colonies in the 15th century CE.