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The limits and potential of paleogenomic techniques for reconstructing grapevine domestication

Posted on August 11, 2016 by ARCAS

Publication date: August 2016Source:Journal of Archaeological Science, Volume 72 Author(s): Nathan Wales, Jazmín Ramos Madrigal, Enrico Cappellini, Aldo Carmona Baez, José Alfredo Samaniego Castruita, J. Alberto Romero-Navarro, Christian Carøe, María C. Ávila-Arcos, Fernando Peñaloza, J. Víctor Moreno-Mayar, Boris Gasparyan, Diana Zardaryan, Tamara Bagoyan, Alexia Smith, Ron Pinhasi, Giovanna Bosi, Girolamo Fiorentino, Anna Maria Grasso, Alessandra Celant, Guy Bar-Oz, Yotam Tepper, Allan Hall, Simone Scalabrin, Mara Miculan, Michele Morgante, Gabriele Di Gaspero, M. Thomas P. GilbertIn ancient DNA (aDNA) research, evolutionary and archaeological questions are often investigated using the genomic sequences of organelles: mitochondrial and chloroplast DNA. Organellar genomes are found in multiple copies per living cell, increasing their chance of recovery from archaeological samples, and are inherited from one parent without genetic recombination, simplifying analyses. While mitochondrial genomes have played a key role in many mammalian aDNA projects, including research focused on prehistoric humans and extinct hominins, it is unclear how useful plant chloroplast genomes (plastomes) may be at elucidating questions related to plant evolution, crop domestication, and the prehistoric movement of botanical products through trade and migration. Such analyses are particularly challenging for plant species whose genomes have highly repetitive sequences and that undergo frequent genomic reorganization, notably species with high retrotransposon activity. To address this question, we explored the research potential of the grape (Vitis vinifera L.) plastome using targeted-enrichment methods and high-throughput DNA sequencing on a collection of archaeological grape pip and vine specimens from sites across Eurasia dating ca. 4000 BCE–1500 CE. We demonstrate that due to unprecedented numbers of sequence insertions into the nuclear and mitochondrial genomes, the grape plastome provides limited intraspecific phylogenetic resolution. Nonetheless, we were able to assign archaeological specimens in the Italian peninsula, Sardinia, UK, and Armenia from pre-Roman to medieval times as belonging to all three major chlorotypes A, C, and D found in modern varieties of Western Europe. Analysis of nuclear genomic DNA from these samples reveals a much greater potential for understanding ancient viticulture, including domestication events, genetic introgression from local wild populations, and the origins and histories of varietal lineages.

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From radiocarbon analysis to interpretation: A comment on “Phytolith Radiocarbon Dating in Archaeological and Paleoecological Research: A Case Study of Phytoliths from Modern Neotropical Plants and a Review of the Previous Dating Evidence”, Journal of Archaeological Science (2015), doi: 10.1016/j.jas.2015.06.002.” by Dolores R. Piperno

Posted on August 11, 2016 by ARCAS

Publication date: July 2016Source:Journal of Archaeological Science, Volume 71 Author(s): Guaciara M. Santos, Anne Alexandre, Christine A. PriorThe paper “Phytolith Radiocarbon Dating in Archaeological and Paleoecological Research: A Case Study of Phytoliths from Modern Neotropical Plants and a Review of the Previous Dating Evidence” by Dolores R. Piperno presents radiocarbon analysis of phytoliths from modern Neotropical plants collected between 1964 and 2013. The analyses presented were intended to rebut the emerging hypothesis that invokes root-plant uptake, transport and reallocation of soil organic carbon into phytoliths that has been recently put forward as an explanation for the anomalous radiocarbon (14C) ages (of hundreds to thousands of years old) reported for modern grass phytoliths in Santos et al. (2010a, 2012a,b). We believe that the results presented in Piperno (2015) lack methodological rigor, mostly due to the absence of any procedural blank assessment, and that the attempts to disprove the hypothesis of uptake of soil organic matter (SOM) by phytoliths in Santos et al. (2012a) are not supported by a careful analysis. Rather than supporting the position that 100% of the carbon in phytoliths is of photosynthetic origin, which allows the use of phytolith carbon (or phytC) as a dating tool, the analysis of 14C in phytoliths from modern Neotropical plants presented in the study shows that the 14C ages are strongly affected by other sources of carbon. In this comment, we carefully reassess the 14C results in phytoliths from modern Neotropical plants presented in Piperno (2015) in the context of the 14C bomb-pulse methodology, SOM ages and turnover rates, and offer an alternative interpretation of the experimental results.

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Secrets of the Anglo-Saxon goldsmiths: Analysis of gold objects from the Staffordshire Hoard

Posted on August 11, 2016 by ARCAS

Publication date: August 2016Source:Journal of Archaeological Science, Volume 72 Author(s): Eleanor Blakelock, Susan La Niece, Chris FernThe Staffordshire Hoard is the largest ever find of Anglo-Saxon gold and silver metalwork. The collection comprises many hundreds of objects, in approximately 3900 fragments. Most objects are fittings from swords, but there are also fragments from at least one helmet, and a small but significant collection of Christian objects.An initial study of 16 gold objects from the collection suggested that some form of deliberately induced depletion gilding had taken place to remove both silver and copper from the surface of the metal (Blakelock, In press). Subsequently, both surface and quantitative core alloy SEM-EDX analysis was undertaken on a further 114 Hoard objects. Over 222 individual components (i.e. different parts of objects) were analysed during this study.This is the largest quantitative survey of Anglo-Saxon gold and, contrary to expectations, no reliable relationship was found between the fineness of alloy used and object date, although the low copper content is consistent with the use of recycled coinage as a source of gold. However, over 100 components were judged to be deliberately depleted in silver at their surface which, it is argued, was the result of a deliberate and probably widespread Anglo-Saxon workshop practice. Previously unrecognised, this involved the depletion gilding of sheet gold to create contrast between decorative components, as well as to enhance colour. Furthermore, in the light of the identification of this systematic surface enrichment, similar approaches should be considered to investigate goldsmithing practices in other cultures and time frames.

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Statistically robust representation and comparison of mortality profiles in archaeozoology

Posted on August 11, 2016 by ARCAS

Publication date: July 2016Source:Journal of Archaeological Science, Volume 71 Author(s): Pascale Gerbault, Rosalind Gillis, Jean-Denis Vigne, Anne Tresset, Stéphanie Bréhard, Mark G. ThomasArchaeozoological mortality profiles have been used to infer site-specific subsistence strategies. There is however no common agreement on the best way to present these profiles and confidence intervals around age class proportions. In order to deal with these issues, we propose the use of the Dirichlet distribution and present a new approach to perform age-at-death multivariate graphical comparisons. We demonstrate the efficiency of this approach using domestic sheep/goat dental remains from 10 Cardial sites (Early Neolithic) located in South France and the Iberian Peninsula. We show that the Dirichlet distribution in age-at-death analysis can be used: (i) to generate Bayesian credible intervals around each age class of a mortality profile, even when not all age classes are observed; and (ii) to create 95% kernel density contours around each age-at-death frequency distribution when multiple sites are compared using correspondence analysis. The statistical procedure we present is applicable to the analysis of any categorical count data and particularly well-suited to archaeological data (e.g. potsherds, arrow heads) where sample sizes are typically small.

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The Sima de los Huesos Crania: Analysis of the cranial breakage patterns

Posted on August 11, 2016 by ARCAS

Publication date: August 2016Source:Journal of Archaeological Science, Volume 72 Author(s): Nohemi Sala, Ana Pantoja-Pérez, Juan Luis Arsuaga, Adrián Pablos, Ignacio MartínezThe Sima de los Huesos (SH) site has provided the largest collection of hominin crania in the fossil record, offering an unprecedented opportunity to perform a complete Forensic-Taphonomic study on a population from the Middle Pleistocene. The fractures found in seventeen crania from SH display a postmortem fracturation pattern, which occurred in the dry bone stage and is compatible with collective burial assemblages. Nevertheless, in addition to the postmortem fractures, eight crania also display some typical perimortem traumas. By using CT images we analyzed these fractures in detail. Interpersonal violence as a cause for the perimortem fractures can be confirmed for one of the skulls, Cranium 17 and also probable for Cranium 5 and Cranium 11. For the rest of the crania, although other causes cannot be absolutely ruled out, the violence-related traumas are the most plausible scenario for the perimortem fractures. If this hypothesis is confirmed, we could interpret that interpersonal violence was a recurrent behavior in this population from the Middle Pleistocene.

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Long-term rhythms in the development of Hawaiian social stratification

Posted on August 11, 2016 by ARCAS

Publication date: July 2016Source:Journal of Archaeological Science, Volume 71 Author(s): Thomas S. DyeThe tempo plot, a statistical graphic designed for the archaeological study of rhythms of the long term that embodies a theory of archaeological evidence for the occurrence of events, is introduced. The graphic summarizes the tempo of change in the occurrence of archaeological events using the model states generated by the Markov Chain Monte Carlo routine at the heart of Bayesian calibration software. Tempo plots are applied to the archaeological record of Hawai‘i to expose rhythms of i) tradition in taro pond-field construction, ii) innovation in temple construction, and iii) fashion in the harvest of branch coral for use as a religious offering. Rhythms of the long term identify a hitherto unrecognized transformation of religious practice in Hawai‘i, establish temporal coincidence in temple construction in leeward sections of Maui and Hawai‘i Islands previously described as regionally idiosyncratic, suggest shallow temporal limits to the use of the direct historical approach in Hawai‘i, and disclose processes at work in the political economy recorded at the time of western Contact.

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Bell Beaker and the evolution of resource management strategies in the southwest of the Iberian Peninsula

Posted on August 11, 2016 by ARCAS

Publication date: August 2016Source:Journal of Archaeological Science, Volume 72 Author(s): Daniel García Rivero, Jesús María Jurado Núñez, Ruth TaylorThis paper addresses the plain common pottery associated with Beaker contexts in the Southwest of the Iberian Peninsula. The detailed systematic study focuses on the pottery assemblage provided by one of the region’s most important settlements, San Blas (Badajoz, Spain), while comparisons are made with other important sites in the study area. By means of the stratigraphic, typological and statistical analysis of the data, the main patterns of change in this material culture throughout the temporal sequence are identified and the historical explanatory factors are inferred. Specifically, during the second half of the 3rd millennium cal BC, an important change took place in the management of economic risk, which is materialised by a significant reduction in food storage and by the more immediate direct or indirect consumption of resources. We suggest that these patterns reflect a shift towards a short-term projection of the future, in a context with strong evidence of instability.

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Sediments or soils? Multi-scale geoarchaeological investigations of stratigraphy and early cultivation practices at Kuk Swamp, highlands of Papua New Guinea

Posted on August 11, 2016 by ARCAS

Publication date: Available online 22 July 2016Source:Journal of Archaeological Science Author(s): Tim Denham, Elle GronoKuk Swamp is a globally significant archaeological site of early agriculture in the highlands of Papua New Guinea. Mixed-method and multi-scalar investigations of the stratigraphy and selected feature fills at Kuk were instrumental in determining the character of plant exploitation and agricultural practices there during the early and mid Holocene. In this paper, macro-scale (field recording), meso-scale (X-radiography) and micro-scale (thin section micromorphology) analyses are presented in summary form for a stratigraphic column, as well as for a palaeochannel and palaeosurfaces associated with plant exploitation at c.10,000 cal BP and cultivation at 7000–6400 cal BP. Major and minor stratigraphic units have been characterised, primary and secondary formation processes differentiated, and the anthropic associations of specific stratigraphic units determined, especially in regards to cultivation. The Kuk research highlights several methodological problems with the investigation of early cultivation on allophane-rich soils in tropical environments.

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Documenting the initial appearance of domestic cattle in the Eastern Fertile Crescent (northern Iraq and western Iran)

Posted on August 11, 2016 by ARCAS

Publication date: August 2016Source:Journal of Archaeological Science, Volume 72 Author(s): Benjamin S. Arbuckle, Max D. Price, Hitomi Hongo, Banu ÖksüzIn this paper we address the timing of and mechanisms for the appearance of domestic cattle in the Eastern Fertile Crescent (EFC) region of SW Asia through the analysis of new and previously published species abundance and biometric data from 86 archaeofaunal assemblages. We find that Bos exploitation was a minor component of animal economies in the EFC in the late Pleistocene and early Holocene but increased dramatically in the sixth millennium BC. Moreover, biometric data indicate that small-sized Bos, likely representing domesticates, appear suddenly in the region without any transitional forms in the early to mid sixth millennium BC. This suggests that domestic cattle were imported into the EFC, possibly associated with the spread of the Halaf archaeological culture, several millennia after they first appear in the neighboring northern Levant.

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Improvement of laser ablation in situ micro-analysis to identify diagenetic alteration and measure strontium isotope ratios in fossil human teeth

Posted on August 11, 2016 by ARCAS

Publication date: June 2016Source:Journal of Archaeological Science, Volume 70 Author(s): M. Willmes, L. Kinsley, M.-H. Moncel, R.A. Armstrong, M. Aubert, S. Eggins, R. GrünStrontium isotope ratios measured in fossil human teeth are a powerful tool to investigate past mobility patterns. In order to apply this method, the sample needs to be investigated for possible diagenetic alteration and a least destructive analytical technique needs to be employed for the isotopic analysis. We tested the useability of U, Th, and Zn distribution maps to identify zones of diagenetic overprint in human teeth. Areas with elevated U concentrations in enamel were directly associated with diagenetic alterations in the Sr isotopic composition. Once suitable domains within the tooth are identified, strontium isotope ratios can be determined either with micro-drilling followed by TIMS analysis or in situ LA-MC-ICP-MS. Obtaining accurate 87Sr/86Sr isotope ratios from LA-MC-ICP-MS is complicated by the potential occurrence of a significant direct interference on mass 87 from a polyatomic compound. We found that this polyatomic compound is present in our analytical setup but is Ar rather than Ca based, as was previously suggested. The effect of this interference can be significantly reduced by tuning the instrument for reduced oxide levels. We applied this improved analytical protocol to a range of human and animal teeth and compared the results with micro-drilling strontium isotopic analysis using TIMS. Tuning for reduced oxide levels allowed the measurement of accurate strontium isotope ratios from human and animal tooth enamel and dentine, even at low Sr concentrations. The average offset between laser ablation and solution analysis using the improved analytical protocol is 38 ± 394 ppm (n = 21, 2σ). LA-MC-ICP-MS thus provides a powerful alternative to micro-drilling TIMS for the analysis of fossil human teeth. This method can be used to untangle diagenetic overprint from the intra-tooth isotopic variability, which results from genuine changes in 87Sr/86Sr isotope ratios related to changes in food source, and by extension mobility.

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