After the Romans had left their former province “Raetia II” (today southern Bavaria) in AD 488, the hitherto unknown tribe of “baiovarii” (Bavarians) was first recorded in AD 551. Current ...archaeological theory claims that this tribe was founded by native Celts, Roman populations, and Germanic mercenaries previously recruited by the Roman military. The geochemical diversity of Bavaria permits the application of Sr isotope analyses for the reconstruction of migration events. Analysis of tooth/bone pairs of 70 individuals from a burial site associated with a Roman fortress revealed that 30% of the dead were primarily non-local to the Roman province but originated from north-eastern areas. A relatively higher number of female immigrants was identified which is best explained by exogamy. Serial analyses of complete dentitions revealed that several males had entered the province as small children and thus cannot have been recruited mercenaries. Such a definition of the ontogenetic stage of an individual at the time of its residence change offers new perspectives for the evaluation of migration events in the past.
Stable isotopic ratios from archaeological bone collagen are valid palaeodietary indicators, but depend on sufficiently well preserved molecules and several collagen quality criteria have to be ...fulfilled (mostly collagen wt%, C%; N%, C/N molar ratio). For a reassessment of these quality criteria, and a better understanding of the chemical degradation of bone collagen, experimentally degraded modern bones and 54 archaeological human bones were investigated. In the course of the experimental degradation, alterations of isotopic ratios were paralleled by altered collagen quality criteria. The contrary was found in the case of the archaeological specimens. This implies that the commonly used collagen quality criteria may be insufficient and do not guarantee that stable isotopic values of the gelatine extracts will still represent the original biological signal.
During the early Holocene two main paleoamerican cultures thrived in Brazil: the Tradição Nordeste in the semi-desertic Sertão and the Tradição Itaparica in the high plains of the Planalto Central. ...Here we report on paleodietary singals of a Paleoamerican found in a third Brazilian ecological setting--a riverine shellmound, or sambaqui, located in the Atlantic forest. Most sambaquis are found along the coast. The peoples associated with them subsisted on marine resources. We are reporting a different situation from the oldest recorded riverine sambaqui, called Capelinha. Capelinha is a relatively small sambaqui established along a river 60 km from the Atlantic Ocean coast. It contained the well-preserved remains of a Paleoamerican known as Luzio dated to 9,945±235 years ago; the oldest sambaqui dweller so far. Luzio's bones were remarkably well preserved and allowed for stable isotopic analysis of diet. Although artifacts found at this riverine site show connections with the Atlantic coast, we show that he represents a population that was dependent on inland resources as opposed to marine coastal resources. After comparing Luzio's paleodietary data with that of other extant and prehistoric groups, we discuss where his group could have come from, if terrestrial diet persisted in riverine sambaquis and how Luzio fits within the discussion of the replacement of paleamerican by amerindian morphology. This study adds to the evidence that shows a greater complexity in the prehistory of the colonization of and the adaptations to the New World.
Yersinia pestis has been identified as the causative agent of the Black Death pandemic in the 14(th) century. However, retrospective diagnostics in human skeletons after more than 600 years are ...critical. We describe a strategy following a modern diagnostic algorithm and working under strict ancient DNA regime for the identification of medieval human plague victims. An initial screening and DNA quantification assay detected the Y. pestis specific pla gene of the high copy number plasmid pPCP1. Results were confirmed by conventional PCR and sequence analysis targeting both Y. pestis specific virulence plasmids pPCP1 and pMT1. All assays were meticulously validated according to human clinical diagnostics requirements (ISO 15189) regarding efficiency, sensitivity, specificity, and limit of detection (LOD). Assay specificity was 100% tested on 41 clinically relevant bacteria and 29 Y. pseudotuberculosis strains as well as for DNA of 22 Y. pestis strains and 30 previously confirmed clinical human plague samples. The optimized LOD was down to 4 gene copies. 29 individuals from three different multiple inhumations were initially assessed as possible victims of the Black Death pandemic. 7 samples (24%) were positive in the pPCP1 specific screening assay. Confirmation through second target pMT1 specific PCR was successful for 4 of the positive individuals (14%). A maximum of 700 and 560 copies per µl aDNA were quantified in two of the samples. Those were positive in all assays including all repetitions, and are candidates for future continuative investigations such as whole genome sequencing. We discuss that all precautions taken here for the work with aDNA are sufficient to prevent external sample contamination and fulfill the criteria of authenticity. With regard to retrospective diagnostics of a human pathogen and the uniqueness of ancient material we strongly recommend using a careful strategy and validated assays as presented in our study.
The so-called sea spray effect influences animals and humans living in coastal regions. As a consequence, δ13Ccarbonate, δ18Ocarbonate, δ18Ophosphate, and δ34Scollagen isotope values of affected ...individuals are more positive than otherwise expected. However, the effect is hidden in the case of humans who actually might have consumed marine food what would (partly) explain their isotopic signature.
In order to correct for the sea spray effect in humans the dietary proportions were calculated based on the δ13Ccollagen and δ15Ncollagen isotope values using stable isotope mixing models. Four different programs (SISUS, simmr, IsotopeR, MixSIAR) were applied which resulted in quite different calculated diets.
Each individual human can be corrected for the sea spray effect using the calculated proportion of terrestrial food (e.g. domesticated mammals, plants) and the approximated sea spray effect for each isotopic system. The differences in the calculated food proportions detected for the different mixing model programs, however, lead to differences in the correction procedure. We suggest using the dietary proportions as obtained by probabilistic SISUS rather than those of the Bayesian programs (simmr, IsotopeR, MixSIAR).
The correction against the sea spray effect using the dietary proportions calculated by SISUS was supported by Gaussian Mixture Model (GMM) clustering which also enables the identification of probably non-local individuals in the dataset.
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•Sea spray effect leads to mistaken interpretation of stable isotope values of humans.•Sea spray correction is possible by calculation of terrestrial dietary proportions.•Different isotopic mixing models (SISUS, simmr, IsotopeR, and MixSIAR) were applied.•Calculated dietary proportions differ substantially between the different programs.•Sea spray correction of human isotope data should be based on SISUS model.
The application of mixing models for the sourcing of dietary end members, which mix into consumer collagen δ¹³C and δ¹⁵N isotopic ratios, has clear benefits for understanding human palaeodiet and ...human and vertebrate palaeoecology. This is because traditional visual or conventional statistical interpretations of bivariate plots may be erroneous or misleading. In terms of their biological meaning, measured isotopic ratios are proxies, therefore, an in-depth reflection on their intended purpose is requisite prior to analysis. A detailed reconstruction of individual palaeodiet is impossible, but an assessment of changes in the importance of gross dietary end members should provide valuable clues to ancient subsistence economies. Mixing models require the establishment of isotopic data for a considerable amount of bioarchaeological finds associated with human skeletons. However, when discussed within the archaeological context, they provide feasible and plausible solutions. More-over, mixing models offer the opportunity to hypothesize "missing end members", the traces of which do not show up in the archaeological record at all.
The analysis of stable isotopes in archaeological human and animal skeletal finds is a routine method in the field of archaeometry. Multi-dimensional datasets are this way easily generated what, ...however, demands new interpretive approaches. Cluster analyses are capable of detecting multi-dimensional similarities among the isotopic signatures and are thus superior over traditional uni- and bivariate evaluations. This study aims to demonstrate the potential of Gaussian Mixture Model (GMM) clustering for palaeodiet reconstruction. We reevaluate previously published isotopic datasets obtained on early medieval skeletal finds from Upper Bavaria (Germany), also including some individuals from "special burials", e.g., from separated burial sites or circular enclosures. This manageable and easy-to-understand dataset contains four-dimensional isotope signatures (δ
C
, δ
N, δ
C
, δ
O
) of 27 individuals. We illustrate the iterative process of cluster analysis and the additional benefit of its outcome for the interpretation of the data. This includes the recognition of noisy isotope data and of those isotope systems that are essential. In our example, three isotope systems were required for a correct palaeodiet reconstruction. While δ
C
and δ
N values are commonly used for palaeodiet reconstructions, δ
C
values, including additional information on dietary carbohydrates and fats, are required for a meaningful cluster separation and, thus, the interpretation of the individuals' diet. No general correlation between dietary quality and grave goods was detectable.
Population genomics of Bronze Age Eurasia Allentoft, Morten E; Sikora, Martin; Sjögren, Karl-Göran ...
Nature (London),
06/2015, Letnik:
522, Številka:
7555
Journal Article
Recenzirano
Odprti dostop
The Bronze Age of Eurasia (around 3000-1000 BC) was a period of major cultural changes. However, there is debate about whether these changes resulted from the circulation of ideas or from human ...migrations, potentially also facilitating the spread of languages and certain phenotypic traits. We investigated this by using new, improved methods to sequence low-coverage genomes from 101 ancient humans from across Eurasia. We show that the Bronze Age was a highly dynamic period involving large-scale population migrations and replacements, responsible for shaping major parts of present-day demographic structure in both Europe and Asia. Our findings are consistent with the hypothesized spread of Indo-European languages during the Early Bronze Age. We also demonstrate that light skin pigmentation in Europeans was already present at high frequency in the Bronze Age, but not lactose tolerance, indicating a more recent onset of positive selection on lactose tolerance than previously thought.
87Sr/86Sr isotopic ratios in skeletal remains of archaeological vertebrates are used for provenance analysis since long. However, the definition of the past bioavailable isotopic ratio at the site of ...recovery is not known beforehand and geological maps can provide no more than gross expectations. Therefore, the assessment of the “local Sr isotopic signature” is still of crucial importance. In this study, we present a tool for the prediction of such local isotopic signatures by creating a concentration weighted mixing model that links lithospheric, biospheric, and atmospheric strontium per site. The major strontium sources and their input into an animal's body were assessed by choosing elemental strontium and its isotopic signature in groundwater, soil, vegetation, and precipitation as components for the mixing model, augmented by literature values. The model was applied to 24 sites located in the alpine transect of the Inn-Eisack-Adige-Brenner passage across the European Alps, a passage used since the Mesolithic. Predicted local bioavailable 87Sr/86Sr ratios were compared with measured values from locally excavated archaeozoological bone samples from three taxa of large and mainly residential vertebrates (cattle, pig, red deer) to verify the models' accuracy. With regard to the fact that the environmental samples predict the past local bioavailable 87Sr/86Sr at a specific site while the vertebrates had different and species-specific home ranges, thereby integrating strontium from a region of primarily unknown size, the model is capable of assigning reasonable expectation values. For 11 sites, up to 100% of the vertebrate isotopic signatures were correctly predicted. Mismatches at the remaining sites are explainable by special environmental factors, and also the fact that some import of animals can never be excluded beforehand. Suggestions for site-specific adjustments of the model are made.
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•A mixing model for the prediction of local archaeofaunal 87Sr/86Sr was established.•87Sr/86Sr and Sr content of environmental samples were measured: soil, groundwater and wood.•Local 87Sr/86Sr spans were calculated for 24 sites and compared with archaeozoological material.•Results suggest the model to be a valuable tool for the determination of local 87Sr/86Sr spans.
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