Camilla Speller

A critical challenge of the 21st century is to understand and minimise the effects of human activities on biodiversity. Cetaceans are a prime concern in biodiversity research, as many species still suffer from human impacts despite decades of management and conservation efforts. Zooarchaeology constitutes a valuable approach for informing conservation and management decisions by providing baseline information on the past distribution and human uses of species. However, traditional morphological species identification of mixed assemblage bones can be challenging, particularly in the case of cetaceans. To address this issue, we applied and evaluated the performance of three biomolecular approaches – Sanger sequencing, shotgun sequencing and collagen peptide fingerprinting (ZooMS) – for species identification in a mixed assemblage of 800 to 1600 years old odontocete (toothed whale) samples from the site of Chersonesus in Crimea, Ukraine. We found that ZooMS allowed for identification to the taxonomic level for 28 of our 30 samples (> 90%), identifying them as either “porpoise” or “dolphin”, and approximately half of those samples could be further identified to species level with the shotgun sequencing approach. In addition, shotgun sequencing produced several complete ancient odontocete mitogenomes and auxiliary nuclear genomic data for further exploration in a population genetic context. In contrast, both morphological identification and Sanger sequencing lacked taxonomic resolution and/or resulted in misclassification of samples. We found that the combination of ZooMS and shotgun sequencing provides a powerful tool in zooarchaeology, and here allowed for a deeper understanding of past marine resource use and its implication for current management and conservation of Black Sea odontocetes.

The domestication and transmission of cereals is one of the most fundamental components of early farming, but direct evidence of their use in early culinary practices and economies has remained frustratingly elusive. Using analysis of a well-preserved Early Bronze Age wooden container from Switzerland, we propose novel criteria for the identification of cereal residues. Using gas chromatography mass spectrometry (GC-MS), we identified compounds typically associated with plant products, including a series of phenolic lipids (alkylresorcinols) found only at appreciable concentration in wheat and rye bran. The value of these lipids as cereal grain biomarkers were independently corroborated by the presence of macrobotanical remains embedded in the deposit, and wheat and rye endosperm peptides extracted from residue. These findings demonstrate the utility of a lipid-based biomarker for wheat and rye bran and offer a methodological template for future investigations of wider range of archaeological contexts. Alkylresorcinols provide a new tool for residue analysis which can help explore the spread and exploitation of cereal grains, a fundamental component of the advent and spread of farming. One of the challenges in identifying cereals through organic residue analysis is their relatively low content of chemically stable lipid compounds and high content of carbohydrate (starch) which is rapidly solubilized during cooking and quickly degrades in the burial environment. So whilst edible plants with oil rich seeds and epicutic-ular leaf waxes have been widely identified in ceramic vessels 1, 2 , reports of cereals are notable by their absence. In some cases, more recalcitrant sterol and terpenoid compounds persist but these rarely offer any taxonomic resolution. One exception is the identification of miliacin in ceramics 3 , a pentacyclic triterpene methyl ether found in broomcorn millet (Panicum miliaceum). However, no such biomarkers currently exist for the identification of other cereals, such as maize, foxtail millet, rice and the major Western Eurasia crops of wheat, barley, and rye. Indeed, much of what we know of the history of cereals is derived from macro-and micro-botanical analysis 4–8 , typically charred grains or phytoliths, although this has now been extended by recovery of ancient DNA retrieved from wheat seeds 9, 10. However, botanical remains in archaeological sites have not always been systematically collected and archived, and their survival may be compromised by cooking practices, food processing and environmental conditions 6, 11, 12. Furthermore these remains are usually found in contexts associated with plant cultivation , processing and storage rather than consumption. Yet, it is the latter which is particularly relevant to our understanding of the cultural value of these foods, particularly to distinguish their role as dietary staples, in the production of fermented products such as beer and bread, or even as exotic luxuries.

Following the discovery in the late 1980s that hard tissues such as bones and teeth preserve genetic information, the field of ancient DNA analysis has typically concentrated upon these substrates. The onset of high-throughput sequencing, combined with optimized DNA recovery methods, has enabled the analysis of a myriad of ancient species and specimens worldwide, dating back to the Middle Pleistocene. Despite the growing sophistication of analytical techniques, the genetic analysis of substrates other than bone and dentine remain comparatively " novel ". Here, we review analyses of other biological substrates which offer great potential for elucidating phylogenetic relationships, paleoenvironments, and microbial ecosystems including (1) archaeological artifacts and ecofacts; (2) calcified and/or mineralized biological deposits; and (3) biological and cultural archives. We conclude that there is a pressing need for more refined models of DNA preservation and bespoke tools for DNA extraction and analysis to authenticate and maximize the utility of the data obtained. With such tools in place the potential for neglected or underexploited substrates to provide a unique insight into phylogenetics, microbial evolution and evolutionary processes will be realized.

Accurate sex identification of archaeological turkey remains is important for deciphering hunting and husbandry practices in pre-contact North America, particularly in the Southwest United States and Mesoamerica where domestic turkeys were raised. Although the sexual dimorphism of turkeys means that relatively complete elements can be distinguished using osteometric approaches, sexing fragmentary or juvenile remains is challenging. Here, we propose a simple and highly-sensitive co-amplification approach which targets highly-repetitive DNA (hrDNA) sequences on the turkey W chromosome. This technique simultaneously co-amplifies both hrDNA and mitochondrial DNA (mtDNA) fragments: the amplification of the W chromosome identifies the heterogametic sex (females), while the mtDNA fragment acts as an internal positive control to monitor for false negative results. To demonstrate the sensitivity and accuracy of this technique, we applied it to 20 modern turkeys and 117 archaeological turkey bones from 25 sites (ca. AD700–1700), including 32 samples from Sand Canyon Pueblo (AD1250–1300). We amplified ancient DNA from 86% of the ancient remains, demonstrating the sensitivity of the technique for targeting nuclear DNA. The correspondence between morphological size and the genetic sex identification for 100% of the complete skeletal elements demonstrates the accuracy and robusticity of this approach. Although within the larger regional assemblage, more males than females were identified (61% vs 39%), the site-specific analysis at Sand Canyon Pueblo suggests that adult male and female turkeys were present in a relatively even ratio.

The great majority of phenotypic characteristics are complex traits, complicating the identification of the genes underlying their expression. However, both methodological and theoretical progress in genome-wide association studies have resulted in a much better understanding of the underlying genetics of many phenotypic traits, including externally visible characteristics (EVCs) such as eye and hair color. Consequently, it has become possible to predict EVCs from human samples lacking phenotypic information. Predicting EVCs from genetic evidence is clearly appealing for forensic applications involving the personal identification of human remains. Now, a recent paper has reported the genetic determination of eye and hair color in samples up to 800 years old. The ability to predict EVCs from ancient human remains opens up promising perspectives for ancient DNA research, as this could allow studies to directly address archaeological and evolutionary questions related to the temporal and geographical origins of the genetic variants underlying phenotypes.The great majority of phenotypic characteristics are complex traits, complicating the identification of the genes underlying their expression. However, both methodological and theoretical progress in genome-wide association studies have resulted in a much better understanding of the underlying genetics of many phenotypic traits, including externally visible characteristics (EVCs) such as eye and hair color. Consequently, it has become possible to predict EVCs from human samples lacking phenotypic information. Predicting EVCs from genetic evidence is clearly appealing for forensic applications involving the personal identification of human remains. Now, a recent paper has reported the genetic determination of eye and hair color in samples up to 800 years old. The ability to predict EVCs from ancient human remains opens up promising perspectives for ancient DNA research, as this could allow studies to directly address archaeological and evolutionary questions related to the temporal and geographical origins of the genetic variants underlying phenotypes.

We propose a simple and effective approach to simultaneously co-amplify both cytochrome b and D-loop fragments to evaluate DNA preservation and to monitor possible contaminations in the analysis of degraded animal DNA samples. We have applied this approach to over 200 ancient salmon samples and 25 ancient whale DNA samples, clearly demonstrating its multiple benefits for analysis of degraded DNA samples, and the ease in which co-amplification can be optimized for different taxa. This simple, cost-efficient and genomic DNA-saving approach can be used routinely in the analysis of minute and degraded DNA samples in wildlife forensics, food inspection, conservation biology and ancient faunal remains.

Domestic horses played a pivotal role in ancient China, but their exact origin remains controversial. To investigate the origin of Chinese domestic horses, we analyzed mitochondrial DNA (mtDNA) from 35 horse remains, aged between 4000 and 2000 years, excavated from nine archaeological sites in northern China. The Chinese ancient horses exhibited high matrilineal diversity, falling into all the seven haplogroups (A–G) observed in modern horses. These results suggest that several maternal lines were introduced into the gene pool of Chinese horses in the past. Haplogroups A and F were more prevalent in ancient horses than the other haplogroups. Interestingly, only haplogroups A and F were present in the samples older than 4000 years, while the more recent horses (between 2000 and 3000 years BP) fell into all seven haplogroups. Comparison with DNA data of present-day horses suggests that haplogroup F is like to be an ancient haplogroup of East Asian origin. These analyses also suggest that the origin of Chinese domestic horses is complex, and external mtDNA input occurred after initial domestication. Our results indicate that the Chinese ancient horses are more related to the modern Mongolian horses. Lastly, our results cannot support the previous hypothesis that early Chinese domestic horses were derived from the Przewalski horse.