Paleo-Environmental Reconstruction Using Ancient DNA

• Main Author: Pedersen, Mikkel Winther
• Format: Book
• Language: English
• Published: Natural History Museum of Denmark, Faculty of Science, University of Copenhagen 2016
• Subjects: greenlandic
• Online Access: https://curis.ku.dk/portal/da/publications/paleoenvironmental-reconstruction-using-ancient-dna(40ed4bfd-85f6-41d8-a16d-0b9807cb9160).html; https://soeg.kb.dk/permalink/45KBDK_KGL/fbp0ps/alma99122559631005763

The aim of this thesis has been to investigate and expand the methodology and applicability for using ancient DNA deposited in lake sediments to detect and determine its genetic sources for paleo-environmental reconstruction. The aim was furthermore to put this tool into an applicable context solving other scientifically interesting questions. Still in its childhood, ancient environmental DNA research has a large potential for still developing, improving and discovering its possibilities and limitations in different environments and for identifying various organisms, both in terms of the sampling methods and strategies (taphonomic processes), the more fundamental molecular methodologies (e.g. extraction and sequencing) and eventually the bioinformatic processing. In the enclosed studies we have tried to take some principal steps towards improving this, firstly by reviewing previous research on ancient and modern environmental DNA (Paper 1), secondly by setting up a comparative study (Paper 2) to investigate how an ancient plant DNA (mini)-barcode can reflect other traditional methods (e.g. pollen and macrofossils) for reconstructing floristic history. In prolongation of the results obtained in paper 2 we developed a holistic metagenomic method combined with shotgun sequencing of ancient DNA in lake sediment samples to reconstruct organismal assemblages in addition to the flora e.g. micro-, meso- and megafauna, fungi and microbial communities (Paper 3). Fundamental processes were tested, using a historical record from the botanical garden in the centre of Copenhagen (Paper 4), by comparing this high resolution sediment archive to the historical sources about the anthropogenic activity and disease history. Similarly, we investigated the flora and faunal content of ancient midden deposits from the four distinct Greenlandic cultures over the past 4,000 cal. yrs BP, to investigate the applicability of the molecular record as a supplementary tool to reconstruct the cultures resource economies (Paper 5). Lastly, we felt it was timely for a focused review paper summarizing the past decade of research and addressing the future perspectives for paleo-environment reconstruction using ancient DNA from lake sediment records (Paper 6). The main emphasis in the review is put on the floristic history, hereby reflecting the focus of the studies published. Appending this thesis are three papers (paper 7-9) which are in review or published, and which have been conducted during my time as a PhD student, although they have not been my main focus. They, however, still contain important analysis and results that provide pieces to the complete picture of this thesis and are therefore appended.