Ancient DNA analysis from lake sediments

Over the past decade, lake sediment DNA has been used by an increasing number of studies to trace past agricultural activities, human presence and landscape changes. Sedimentary ancient DNA (sedaDNA) has proven to be a complementary approach to the use of pollen and macrofossil remains in the field of palaeoecology when investigating past community changes, as it allows the direct identification of specific domesticates, rather than employing pollen or non-pollen palynomorphs as proxy indicator species. 

Here we present the application of sedaDNA sequencing to investigate the relative impact of human activities, such as pastoralism, on the vegetation in the catchment of lakes in the Western French Alps and the domestic animal species used at different time periods.

With the application of advanced bioinformatic techniques, we can combine previous data on past and present vegetation with the analysis of mammalian DNA from domestic species found in the lake sediments, to get a more complete picture of not only the vegetation changes, but trace the presence of domesticated species in the lake catchment. The genetic data was obtained through the established method of metabarcoding, which is a relevant tool for reconstructing palaeoenvironments. 

This analysis can demonstrate not only the existence of pastoral practises in the region, but contribute to our understanding of animal mobility patterns, facilitated by isotopic analysis of faunal remains from archaeological sites in the study area. In addition, sedaDNA analyses allow us to investigate the direct impact of transhumance pastoralism in the Western Alps across wide chronological and spatial frameworks. The application of a metabarcoding method can demonstrate the potential of sedimentary ancient DNA in reconstructing palaeoenvironments and its relevance in conceptualising long-term ecosystem changes relating to human and non-human agencies.

Read more about Katharina Dulias work at her University of York profile.