Species identification of skins and development of sheep wool:An interdisciplinary study combining textile research, archaeology, and biomolecular methods

• Main Author: Brandt, Luise Ørsted
• Format: Book
• Language: English
• Published: Det Humanistiske Fakultet, Københavns Universitet 2015
• Subjects: /dk/atira/pure/core/keywords/FacultyOfHumanities; Faculty of Humanities; greenlandic; Saqqaq; Saqqaq culture
• Online Access: https://curis.ku.dk/portal/da/publications/species-identification-of-skins-and-development-of-sheep-wool(7576dd99-7493-4679-b01a-756c635d06e5).html; https://curis.ku.dk/ws/files/141451030/Ph.d._2015_Brandt.pdf

Denmark possesses an extraordinary collection of well-preserved textiles and skins from Danish prehistory as well as archaeological and historical skins and costumes from the circumpolar area. Much research has focused on how these textiles and skin garments were produced. Recently, textile research has endeavoured to move beyond this and investigate prehistoric costumes as the output of interactions between resources, technology and society. As some of these aspects are difficult to investigate archaeologically, especially studies of the character of the raw materials used for textile and skin production, fresh approaches are needed, including new methods. This thesis investigates archaeological and historical skin garments and textiles using an interdisciplinary approach that combines bimolecular methods, archaeology and textile research. The aims of this thesis are first to investigate the development of sheep wool and secondly to species identify archaeological and historical skins. Denmark possesses an extraordinary collection of well-preserved textiles and skins from Danish prehistory as well as archaeological and historical skins and costumes from the circumpolar area. Much research has focused on how these textiles and skin garments were produced. Recently, textile research has endeavoured to move beyond this and investigate prehistoric costumes as the output of interactions between resources, technology and society. As some of these aspects are difficult to investigate archaeologically, especially studies of the character of the raw materials used for textile and skin production, fresh approaches are needed, including new methods. This thesis investigates archaeological and historical skin garments and textiles using an interdisciplinary approach that combines biomolecular methods, archaeology and textile research. The aims of this thesis are first to investigate the development of sheep wool and secondly to species identify archaeological and historical skins. Sheep wool development is investigated by archaeological material, state-of-the-art textile research, and next generation sequencing (NGS) of ancient sheep DNA. Archaeological sources point to the development of a sheep wool that could be used for textile production in the Danish LN II or EBA I (2000-1500 BC). Changes of the wool seem to again take place in the Roman Iron Age (AD 1-400). The genetic analysis of DNA from wool textiles and sheep bones aimed at extracting the entire mitogenome and nuclear markers coding for wool quality. None of the included textiles yielded amplifiable DNA, confirming that environments preserving ancient Danish textiles are generally poor for the preservation of DNA. Two bone samples yielded almost complete mitogenomes, while only a very few of the targeted nuclear markers mapped to the reference genome. The resolution of sheep mitochondrial DNA is, however, too low to generate detailed information of sheep population history and therefore nuclear DNA should be the focus in the future. Three studies focused on the species identification of skins. Traditional species identification by microscopy was proven to be difficult to perform here on ancient and degraded hair materials. Therefore, additional approaches are needed. For those samples not deriving from highly degrading environments, such as the analyzed skins of historical costumes from the circumpolar area, traditional PCR is still a valuable tool for species identification. For samples from degrading enviroments, such as the Danish bogs, Mass Spectrometry (MS)-based peptide sequencing was proven to be a reliable method for species identification. Moreover, MS-based peptide sequencing provided information of the age at death for one of the animal skin samples - information not obtainable by DNA and with crucial implications for the interpretations of preferences of skins and animal husbandry. Online available protein databases used for comparison are still not complete. While the most common domesticated species are well described, the databases did not provide enough resolution of seals and birds to presently justify the species identification by PMF of ancient Greenlandic skin samples dating to the Saqqaq culture. Overall, the success of the analysis of ancient biomolecules is closely connected to the nature and preservation conditions of the sample, and the ability to answer archaeological questions depends on the questions posed and the methods chosen. When such questions are considered, biomolecular methods can provide a good tool to characterize ancient raw materials and investigate their interwoven relationships with production contexts and society.