Biofilm growth in human skeletal material from ancient Mesopotamia

Investigators have long recognised the effects of microbial activity on archaeological bone. These investigators, however, have focused on single or groups of microbes rather than on complex microbial aggregates such as biofilms, a focus that has affected our understanding of archaeological bone biodeterioration. In this paper, we report on the investigation of a biofilm in archaeological human bone from the site of Tell Leilan, Syria (2900–1900 BCE). Scanning electron microscopy indicated that the biofilm is characterised by single cells and microcolonies of bacteria and fungi, as well as calcite crystals that were all embedded within extracellular polymeric substances. Using culture techniques and DNA sequencing, we isolated and identified several microbes from the biofilm including Amycolatopsis sp., Penicillium chrysogenum, Aspergillus sp., Chaetomium sp., and Cladosporium sp. Having characterised the Leilan biofilm, we are now closer to understanding the complex process of bone biodeterioration in archaeological bone collections.     

TRUTH IN THE BONES: RESOLVING THE IDENTITY OF THE FOUNDING ELITE THOROUGHBRED RACEHORSES

Our multidisciplinary study of historic Thoroughbred horses solves two long‐running mysteries in racing history. Eclipse, the greatest racehorse ever known, never lost a race. His skeleton is housed in the Royal Veterinary College, London; however, there is controversy over its authenticity. The 1880 Epsom Derby was won by Bend Or. In one of the great controversies of Thoroughbred racing, the owners of Bend Or were accused of swapping him with another horse, Tadcaster, whose maternal pedigree was more prestigious. Bend Or's skeleton resides at the Natural History Museum, in London. Eclipse and Tadcaster were both extremely popular at stud, and the vast majority of racehorses today are descendents. We compared mitochondrial DNA haplotypes of living and historic Thoroughbred skeletons, including those of Eclipse and Bend Or. Additionally, we compared skeletal morphometrics of Eclipse's skeleton with measurements taken at autopsy. Carbon and nitrogen stable isotopes of a range of skeletal elements were compared in order to establish that the Eclipse skeleton was that of a single horse. Our multidisciplinary data suggest that the putative skeleton is consistent with that of Eclipse. In contrast, mitochondrial DNA haplotype sharing indicated that the skeleton known as Bend Or is most probably that of Tadcaster.     

A novel method for integrated age and sex determination from archaeological cattle mandibles

Analysis of ancient cattle husbandry is compromised by the need for conventional analysis of sex and age at death to use different elements of the skeleton, usually from different individuals. We demonstrate a technique using aDNA acquired from cattle mandibles and combined with age-at-death estimation based on dental eruption in the same specimens. Application to small sample groups from two sites in Na h-Eileanan Siar (the Scottish Western Isles) show a high success rate, and demonstrates the potential for a more nuanced interpretation of ancient cattle husbandry.     

Ancient DNA in archaeological wheat grains: preservation conditions and the study of pre-Hispanic agriculture on the island of Gran Canaria (Spain)

The recovery of ancient DNA from archaeological wheat samples under different preservation conditions was assessed using a number of genetic markers. It was possible to amplify nuclear DNA from desiccated grains but not from charred. The desiccated grain was from a pre-Hispanic grain silo in Gran Canaria and showed excellent DNA preservation, enabling the amplification of the ribosomal DNA markers IGS and ITS, the upstream region of the HMW-glutenin locus and single-locus nuclear microsatellites. Our results demonstrated the presence of both durum and bread wheat in an assemblage of naked grain. We were also able to identify different genotypes in durum wheat and compare these with extant landraces, providing insights into the agrarian practices of the ancient Canarians and the origin of their crops.     

Osteometric and molecular sexing of cattle metapodia

Sex identification of skeletal remains based on morphology is a common practice in Zooarchaeology. Knowledge of the sex distribution of slaughtered or hunted animals may help in the interpretation of e.g. hunting or breeding strategies. Here we investigate and evaluate several osteometric criteria used to assess sex of cattle (Bos taurus) metapodia using molecular sex identification as a control of the metric data. The bone assemblage used to assess these new criteria derives from the Eketorp ringfort in the southern parts of Öland Island in Sweden. One hundred metapodia were selected for molecular analysis of sex and we were able to genetically identify the sex of 76 of these elements. The combined results of the molecular and osteometric analyses confirm a significant size difference between females and males for several measurements for both metacarpals (Mc) and metatarsals (Mt). Our results show that some measurements are applicable for metapodials. These measurements include the slenderness indices such as the Mennerich’s index 1 and 3, as well as the distal breadth (Bd), the breadth between the articular crests (Bcr), and the maximum breadth of the lateral trochlea (BFdl). We show that they can be used for sexing of both metacarpals and metatarsals. The latter measurements offer an opportunity to study fragmented elements and thus a higher number of elements may be utilized for morphological sexing of archaeological bones. Size comparisons of Mc and Mt may also aid in the separation of bulls and oxen.     

Minimally destructive DNA extraction from archaeological artefacts made from whale baleen

Here we demonstrate the successful extraction and amplification of target species DNA from artefacts made of whale baleen collected from excavations of past palaeo-Eskimo and Inuit cultures in Greenland. DNA was successfully extracted and amplified from a single baleen bristle of 1.5 cm length dated based on archaeological context to the period of the Saqqaq culture, more than 4000 years ago and following decades of storage at room temperature at the National Museum. The results reveal ancient baleen in archaeological material as a potential source of DNA that can be used for population genetic studies. We conclude that genetic investigation of historical baleen collections can contribute to our knowledge of the prehistoric population genetics of baleen whales, for example by quantifying the impact of modern whaling on the genetic diversity of bowhead whales.     

Examining Indigenous perspectives on the health implications of large‐scale agriculture in Jalisco,Mexico

In Mexico, as in many other parts of the world, industrial agriculture is dramatically changing rural landscapes and altering relationships with the land. This paper draws on community‐based research from a collaborative international research project that examined the perceived health implications of the agricultural industry for Indigenous peoples in the state of Jalisco, Mexico. Thirty interviews were conducted in a Nahuas community experiencing expanding agribusiness industries. The results of this study show that the implications of export‐oriented agricultural industry for this Nahuas community are complex and, at times, contradictory: employment in the agricultural industry provides community members with much‐needed sources of income, but it is precarious work. At the same time, community members are concerned about the long‐term health and environmental implications, such as increased exposure to chemicals, depletion of the soil and water, and loss of traditional food and lifeways. These results suggest that to better understand the costs and benefits of large‐scale agriculture for Indigenous health, a broad lens of health that is situated in the context of colonial legacies and the particularities of relationships with the land is required.     

Mitochondrial haplogroup M discovered in prehistoric North Americans

We analyzed two mid-Holocene (∼5000 years before present) individuals from North America that belong to mitochondrial DNA (mtDNA) haplogroup M, a common type found in East Asia, but one that has never before been reported in ancient or living indigenous populations in the Americas. This study provides evidence that the founding migrants of the Americas exhibited greater genetic diversity than previously recognized, prompting us to reconsider the widely accepted five-founder model that posits that the Americas were colonized by only five founding mtDNA lineages. Additional genetic studies of prehistoric remains in the Americas are likely to reveal important insights into the early population history of Native Americans. However, the usefulness of this information will be tempered by the ability of researchers to distinguish novel founding lineages from contamination and, as such, we recommend strategies to successfully accomplish this goal.     

Evaluating bone collagen extraction methods for stable isotope analysis in dietary studies

The specific purpose of this study was to compare three different collagen extraction methods commonly used in isotope laboratories conducting dietary studies. We evaluated their resultant differences in δ¹³C and δ¹⁵N, collagen quality and collagen yield. Our study was based on well-preserved skeletal material from the medieval period in Denmark. Our study shows that there is a systematic significant difference in the yield and the δ¹³C values between the three methods. Using the method of DeNiro and Epstein [DeNiro, M.J., Epstein, S., 1981. Influence of diet on the distribution of nitrogen isotopes in animals. Geochimica et Cosmochimica Acta 45, 341–351] with NaOH as cleaning agent, will, according to our study, give δ¹³C values that are on average ±0.32‰ more positive than using the ultra-filtration method [Brown, T.A., Nelson, D.E., Vogel, J.S., Southon, J.R., 1988. Improved collagen extraction by modified Longin method. Radiocarbon 30 (2), 171–177, modified in Richards, M.P., Hedges R.E.M., 1999. Stable isotope evidence for similarities in the types of marine foods used by late Mesolithic humans at sites along the Atlantic coast of Europe. Journal of Archaeological Science 26, 717–722]. The third method, which is a modified version of the second method, excluded the ultra-filtration step. This method seems to give δ¹³C values that lie in between the other methods. Our study did not show any significant difference in δ¹⁵N values. Although the differences between the methods are very small, we conclude that the use of stable isotope analysis in food determination studies requires adherence to routine methods for preparing and measuring samples.