Investigating the early human settlement of Iceland with ancient soil DNA

This project aims to establish if early human settlement of Iceland can be detected and described through the analysis of ancient (centuries-old) DNA (aDNA) in soil. Iceland is an important model system for human-environment interactions, but the timing and ecological impacts of human settlement are contested: aDNA in soil offers a novel approach to these problems.

To generalise the Icelandic experience, we need to understand when humans first settled Iceland and if this event was earlier than the currently accepted date of 874 CE (Landnám in Icelandic). We also need to understand the ecological impact of expanding human populations in the early phases of settlement to a high degree of spatial and temporal resolution.

Finally, to reconstruct ecological change from soil aDNA, we need to understand the mobility and longevity of DNA in the soil.

To establish if early human settlement of Iceland can be detected and described through the analysis of aDNA in soil, we will 1) analyse soil aDNA from three archaeological sites in Iceland and 2) track the fate of experimentally applied exotic DNA. To address when humans first settled Iceland, we will analyse aDNA from pre-Landnám soils, targeting taxa that can only have arrived in Iceland with humans.

To assess the ecological impact of expanding human populations in the early phases of settlement, we will analyse aDNA from soils immediately post-Landnám, comparing our inferences with those derived from well-established proxies. To investigate the mobility and longevity of DNA in the soil, we will apply modern, exotic DNA to test plots and, over a period of six months, repeatedly test for its presence and abundance at different soil depths.

Overall, the project will address long-standing questions about the early human colonisation of Iceland and the test an innovative technique with huge potential for Holocene palaeoenvironmental reconstruction.