夜郎研究的途径之一——势在必行的贵州古人类遗骸DNA研究

贵州古代墓葬、遗址出土的古代人类遗骸,正期待着分子生物学的关注。应用生物DNA技术研究考古人骨,在国内外已日趋完善。它的应用将有助于古夜郎主体民族的识别及许多相关考古学无法解释的问题。这是夜郎考古研究不能忽视的方法,也是夜郎研究的途径之一。     

A Comparison of Three Methods for the Extraction of Phytoliths from Sediments

This paper compares three methods commonly used to extract fossil phytoliths from sediments. A basic procedure using heavy liquid flotation and oxidation is compared with two other procedures across a range of sediment types commonly encountered in archaeological studies. The three procedures are: (1) a heavy liquid flotation method (HLF); (2) a burning method (POW); and (3) another heavy liquid flotation method (HLFPol) similar to HLF, but adapted to allow the extraction of pollen and spores as well as phytoliths, within a single process. Comparisons of the resulting output using these three techniques for phytolith extraction show that different methods can produce different results, and therefore basic techniques should be modified according to the characteristics of the sediments for which they are used. While all the techniques showed similarities in assemblage results, there were problems associated with disaggregation and effective separation of light and heavy fractions, in particular with the POW procedure. The evidence suggests that morphotype selection occurred both within the physical sorting process and in the process of inverting slides to shed excess residue; in both cases it is difficult to suggest a solution to the problem. The results show clearly that the advantages gained by using the POW procedure are largely outweighed by the problems encountered with its use, and because of possible size/shape selection, it is not recommended for general extraction procedures. The heavy liquid flotation procedures, on the other hand, are shown to produce more concentrated residues with higher levels of clarity and less potential than the POW procedure for sample bias. The use of a non-toxic heavy liquid, sodium polytungstate, now allows the process to be used in relative safety. It is recommended that analysts use heavy liquid flotation procedures with chemical treatments specific to sediment requirements.     

“From One Shore to the Other”: Other Revolutions in the Interstices of the Revolution

This interview with Imed Soltani and Federica Sossi focuses on the campaign of the families of the missing Tunisian migrants, “From One Shore to the Other: Lives that Matter”. The campaign started in 2011 to demand that Italian and Tunisian institutions be held accountable for the disappearance of young Tunisian migrants who crossed the Mediterranean to Italy. The campaign brought together the families of Tunisian migrants and the Italian feminist collective “Le Venticinqueundici” as part of a migration struggle that involves the entire region but is rarely taken up as a cross‐shore militant campaign. The conversation between Soltani and Sossi illustrates the strengths of the campaign and the difficulties that arose in running it across shores, and offers a theoretical reflection on the notion of political recognition in an effort to decolonise the gaze on what counts as political subjectivity and political struggle.     

Insights into the processes behind the contamination of degraded human teeth and bone samples with exogenous sources of DNA

A principal problem facing human DNA studies that use old and degraded remains is contamination from other sources of human DNA. In this study we have attempted to contaminate deliberately bones and teeth sampled from a medieval collection excavated in Trondheim, Norway, in order to investigate this poorly understood phenomenon. Five pairs of teeth and bone samples were bathed in water containing various concentrations (from 10⁻⁹ and 10⁻²¹ g/l) of purified ΦX174 DNA. Subsequently the samples were subjected to a routine decontamination protocol involving a bleach bath followed by exposure to λ=254 nm ultraviolet light, prior to DNA extraction and analysis for evidence of the persistence of the contaminant. The results support previous speculation that bone is more susceptible to water‐borne sources of contaminant DNA, although both bone and teeth are readily contaminated and are difficult to decontaminate using the tested protocol. We believe that this is largely due to the porous nature of bone and teeth facilitating the deep penetration of the contaminant DNA. To simulate a more realistic handling situation, 27 further teeth were directly handled and washed, then decontaminated, prior to assaying for the residual presence of the handler's DNA. Surprisingly, although our results suggest that a large proportion of the teeth were contaminated with multiple sources of human DNA prior to our investigation, we were unable to contaminate the samples with further human DNA. One potential explanation may be the deposition of sediment or other structural changes that occur within the samples as they desiccate post‐excavation, which may protect samples from subsequent contamination, but also prevent the efficacy of bleach baths in decontaminating specimens. Copyright © 2006 John Wiley & Sons, Ltd.     

Identification of historical human skeletal remains: a case study using skeletal and dental age,history and DNA

Excavation of an early historical (circa 1900) church cemetery in Cochrane, Alberta, Canada, revealed the graves of six individuals. All but one had been previously excavated and the individuals were re‐interred elsewhere. The remaining grave contained a coffin burial of an infant including most of the skeleton, crowns of forming deciduous teeth, scalp and hair. The remains were excavated and historical research was carried out to determine possible families who had used the cemetery. Skeletal and dental age estimates pointed to a particular individual described in historical records. This identification was confirmed through more precise ageing by dental microstructure, sex determination using DNA, and finally, maternal relatedness by comparison of mtDNA with a living female relative. In addition to describing the analytical methods used, this paper demonstrates the importance of accurately identifying historical burials, particularly when living relatives remain in the community. Copyright © 2004 John Wiley & Sons, Ltd.     

Ectopic paragonimiasis from 400-year-old female mummy of Korea

Of the parasite eggs discovered in ancient samples from Korean archaeological sites, Paragonimus spp. are of particular importance in that they are regarded as one of the most insidious trematode infection sources. Although their infection prevalence decreased rapidly in the early 20th century, archaeoparasitological studies on the species are still required, as historical knowledge of paragonimiasis remains far from comprehensive. Fortunately, we recently were given a chance to examine a medieval Korean mummy in a good state of preservation. Using morphological techniques, we discovered evidence of ectopic paragonimiasis in the sample from the 17th-century female. When the ITS 2 gene was extracted, amplified and sequenced from Paragonimus eggs, it showed 100% homology to the sequences of modern Paragonimus westermani reported from Korea and Japan, forming a cluster distinct from South Asian P. westermani. Our report is the first-ever analysis of ancient Paragonimus DNA from any archaeological field in the world. The ectopic paragonimiasis diagnosis made in this study, especially involving the liver sample, also is the first of its kind in archaeoparasitology.     

Pick the Right Pocket. Sub‐sampling of Bone Sections to Investigate Diagenesis and DNA Preservation

Many archaeological bones display a heterogeneous degradation pattern. Highly degraded bones could contain pockets of well‐preserved bone, harbouring good quality DNA. This dichotomy may explain why the relationships between global bone preservation parameters such as histological integrity, bone mineral crystallinity or collagen yield, and bulk DNA preservation/amplification success rate have been found to be at best, weak to moderate. In this pilot study, we explore whether or not a more localised approach will highlight a stronger relationship between diagenetic parameters and DNA preservation. This study includes a detailed histological characterisation of bone diagenesis in sub‐areas of three bone samples. Regions of the same bone, which displayed differential degrees of preservation or type of diagenesis were sampled for further analysis and both genetic (small scale Illumina MiSeq sequencing) and chemical (Fourier‐transform infrared spectrometric analysis) analyses were performed. The aim was to investigate how bone diagenetic processes relate to DNA preservation at a higher resolution than in previous studies. This is key in order to improve DNA analytical success rates. The expected relationship between bone and DNA preservation (retrieved endogenous DNA) was observed and the results corroborate previous work that DNA preservation is linked to the integrity of bone collagen and mineral. The results further suggest that non‐biological diagenetic alterations such as etching and the presence of mineral infiltrations and inclusions have a negative effect on DNA preservation/extraction. Copyright © 2016 John Wiley & Sons, Ltd.     

Evidence for Differential Ancient DNA Survival in Human and Pig Bones from the Norse North Atlantic

Current models of DNA degradation and previous research on Icelandic human skeletons predict ancient DNA preservation in the Norse North Atlantic faunal remains to be excellent. In contrast, we found that DNA preservation in Viking‐Age pig remains was poor. We posit that this discrepancy in DNA survival between human and faunal remains is due to differing taphonomies. Our results highlight that DNA degradation is strongly dictated by micro‐environmental taphonomic processes even in regions where the climate is conducive to DNA survival. Due to these differences, DNA preservation in animal remains may not be suitable proxies for DNA preservation in associated human remains. Copyright © 2012 John Wiley & Sons, Ltd.     

SEX IDENTIFICATION OF SLAVE SACRIFICE VICTIMS FROM QIN STATE TOMBS IN THE SPRING AND AUTUMN PERIOD OF CHINA USING ANCIENT DNA

Ancient DNA (aDNA) analysis was employed to determine the sex of slave sacrifice victims from Qin State tombs during the Spring and Autumn Period of China. It is difficult to obtain sex information from fragmentary skeleton samples with the aid of skeletal morphology methods. aDNA was extracted from the dentine in selected tooth samples of sacrificial slaves using a modified traditional method, which combines together phenol/chloroform extraction, silicon dioxide adsorption and ultrafiltration concentration. Based on the sequence differences between the amelogenin homologous gene in the X and that in the Y chromosome, a pair of specific primers was designed to identify the sex of the selected samples. In the selected eight typical samples, the aDNA analytical results revealed that three were males and two were females. These findings indicate that molecular sex identification might provide more valuable information for archaeological research on the institution of slave sacrifice in the Spring and Autumn Period of China.