Evolutionary insights from ancient sediments: Opportunities and challenges of microfossil DNA

Ana Prohaska - University of Copenhagen

Sediments have long been a source of invaluable information about the Earth’s life history. The advent of ancient sedimentary DNA has opened a new window into this history. New opportunities include tracking the distribution of specific species across time and space and reconstructing entire ecosystems dating back as far as 2 million years. Today, the field is on the cusp of taking another transformative step in studying the past —tracking evolutionary processes of a broad spectrum of organisms, from viruses and bacteria to higher plants and animals. Achieving this breakthrough depends on developing novel wet lab and computational methods. Sedimentary microfossils lie at the centre of these efforts. Diverse, abundant, and well-preserved in various depositional environments worldwide, microfossils originate from organisms across the tree of life. As such, microfossils hold the potential to provide an unprecedentedly detailed study of evolutionary histories from sediments. However, this potential comes with challenges, including the complexities of isolating microfossils from sediments at scale and efficiently retrieving their DNA. This talk will introduce the exciting opportunities and practical challenges of working with microfossil DNA, with pollen as a case study, and provide an overview of the methodological developments underway.