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1.
Comparisons were made between two commonly used methods for the extraction of ancient DNA from charred plant remains. Using artificially charred wheat seeds, we show that silica-binding is the most efficient method for extraction of DNA. We describe a improved silica-binding procedure, including pre-incubation with N-phenacylthiazolium bromide and increased washing of bound DNA, which yields amplifiable DNA from seeds heated at 200 °C for up to 8 h, conditions which promote the formation of Maillard products which often copurify with aDNA and inhibit subsequent PCRs. We believe that this method will be effective in ancient DNA extraction with most types of charred archaeobotanical material. Both cold- and hot-start PCR procedures gave good amplicon yields with extracts prepared in this way, but cold-start PCRs also resulted in synthesis of short artefact products. Addition of bovine serum albumin to PCRs, an inert carrier substance thought to enhance amplification efficiency by binding contaminants, had no advantageous effect and in fact reduced amplicon synthesis. 相似文献
2.
Terence M. Murphy Nahum Ben-Yehuda R.E. Taylor John R. Southon 《Journal of archaeological science》2011
The “Christmas Cave”, a cave in the Qidron Valley near the Dead Sea and Qumran, has yielded a complex collection of plant-derived rope and fabric artifacts. Using polymerase chain reaction (PCR) to amplify DNA of the samples, we estimated the sizes and determined restriction patterns and base sequences of chloroplast genes, primarily rbcL (gene for the large subunit of ribulose bisphosphate carboxylase). DNA was successfully extracted from all samples, but was limited to sizes of approximately 200–300 base pairs. As expected, the DNA extracted from the samples was identified as coming primarily from flax (Linum usitatissamum L.), but two samples had a significant fraction, and all samples had at least a trace, of hemp (Cannabis sativa L.) DNA. Artifacts from the Christmas Cave were thought to date from Roman times, but it was thought possible that some could be much older. Accelerator mass spectrometry (AMS)-based 14C dating confirmed that the samples contained representatives from both the Roman and Chalcolithic periods. This paper provides a synthesis of DNA, isotope, and literary analysis to illuminate textile history at the Christmas Cave site. 相似文献
3.
Two significant events in the late Holocene history of Madagascar were (a) the arrival of people, and (b) the loss of nearly two dozen species of land vertebrates in the socalled “subfossil extinctions”. The consensus is that the faunal losses occurred shortly subsequent to human arrival, but the timing of these events is poorly constrained. The minimum age for initial human presence on the island may now be set at approximately 2000 bp, on the basis of AMS 14C dates for human-modified femora of extinct dwarf hippos from SW Madagascar. Assuming that this date also marks the beginning of deleterious human interactions with the subfossil fauna, and assuming that this fauna became completely extinct by 900 bp, the width of the anthropogenic “extinction window” may have been as long as c. 1000 a. This estimate, nearly twice the length of previous ones, is close to the unadjusted minimum for the duration of the terminal Pleistocene extinction event in the Americas. Whether or not this length of time comports with theoretical expectations of a “blitzkrieg” pattern of losses is uncertain, but greater refinement in dating the end of the subfossil extinctions is unlikely to produce radically shorter estimates of duration. 相似文献
4.
The site of Finch Camp in the middle Queen Creek area of Arizona, southeast of Phoenix, has produced some of the earliest evidence of utilitarian pottery use in the US Southwest. Using multiple lines of evidence from vessel morphology, surface alteration, and minute fatty acid residues in vessel walls, I evaluate the nascent function of the earliest vessels (mostly neckless jars, or tecomates) and infer a diachronic process of functional expansion from about 350 B.C.-A.D. 400. This evidence provides robust evidence for evaluating various theoretical models of pottery origins. I argue that utilitarian pottery was initially adopted in connection with the intensification of small particulate plant foods (e.g., seeds, grains) and increasing household-level control over resources. Further, vessel functions may have expanded during the early centuries A.D. in response to women’s task-scheduling conflicts stemming from increasing residential stability and growing reliance on low-level horticulture. 相似文献
5.
Work initiated purely as a dating project in support of a craniometric and morphological investigation of domestic dogs from early Peru has proved to have much wider implications. The stable carbon isotoperatios (13C/12C) of hair samples from ten dogs show that maize formed a significant part of their diet. Radiocarbon dates for these remains have confirmed that they belong to the period well after the cultivation of maize was first established. Stable carbon isotope measurements can thus be used to test for the presence of maize as a dietary constituent at earlier sites even where there is otherwise only indirect evidence for its cultivation. Collagen from animal or human bone is a suitable alternative to hair for this purpose and the method has been successfully applied to collagen dating to c. 3000 BC from the Valdivia culture site of Real Alto, Ecuador, as well as to a series of early Peruvian dogs. 相似文献