Ancient DNA from soils and sediments from the Krigstjärn area, northern Sweden : Preservation and detection of Holocene mammal sedaDNA

• Main Author: van Woerkom, Anne
• Format: Bachelor Thesis
• Language: English
• Published: Umeå universitet, Institutionen för ekologi, miljö och geovetenskap 2016
• Subjects: ancient DNA; faunal reconstruction; palaeoecology; lake sediments; glacial vegetation; Physical Geography; Naturgeografi; Alces alces; Northern Sweden
• Online Access: http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-127680

Current knowledge of past vegetation and faunal diversity has been based on pollen and macrofossil analysis from lake sediments. The innovative method of sedimentary ancient DNA (sedaDNA) is a promising, complementary proxy to reconstruct information about past environments. However, to what extent animal DNA can be extracted from old sediments and soils has not been frequently studied. This study explored if ancient DNA of moose (Alces alces), reindeer (Rangifer tarangus), goat (Capra aegagrus) and plants could be extracted from millennia old lake sediments of Lake Krigstjärn and archaeological soil samples in northern Sweden. SedaDNA was successfully extracted and detected from both reindeer and plants DNA, while goats sedaDNA was absent in all sediments. Moose ancient DNA (aDNA) was only detected in the archaeological soils. Yet, there were signs that the applied moose primer set was not optimal for heavily degraded DNA and the validity of this primer needs further research. Earliest detections of reindeer DNA can be dated to ~6500 c. years ago. Oldest sediments contained DNA, indicating sufficient DNA preservation conditions in the sediments of Lake Krigstjärn. Finds of plants DNA in pre-deglaciational sediments may indicate the existence of >9500 year old glacial vegetation. Altogether is sedaDNA a highly promising tool to reconstruct diversity, origin and immigration routes of mammals, but technical issues such as primer set specificity and its purpose should be considered and tested carefully in advance.