Ancient DNA in pollen - Genetic analysis in two Holocene pine populations from Sweden

Recent advances in molecular biology offer now excellent tools to obtain DNA information from well-preserved fossil material and the discovery that ancient DNA can be amplified by polymerase chain reaction (PCR) has added a direct temporal dimension to many evolutionary studies. By using a method we recently developed for the analysis of DNA in fossil pollen, we examined the chloroplast DNA sequence variation among fossil pollen grains of Scots pine (Pinus sylvestris L.) incorporated in a Holocene sediment core collected in central Sweden. DNA sequences data obtained from fossil (100 and 10,000 cal. BP) and modern samples revealed a number of different haplotypes and their relationships were visualised by a statistical parsimony network analysis. Results from this study establish a first genetic link between modern and fossil DNA samples and provide unique genetic information useful for understanding the origin and the evolution of Scots pine ancient populations.