Our March talk will be presented by Professor Robin Allaby of the University of Warwick. Robin previously gave a (virtual) talk to us in 2020, this presentation will provide an update on his research.

Prior to the formation of the present-day North Sea during the mid-Holocene, North-Western Europe was connected through the Doggerland landmass. Whilst it has been known for the past century that forests grew in Doggerland, it has not been clear how this environment compares to the surrounding European areas. Despite the long time periods involved, the DNA of these environments still persists in marine sediments. Sedimentary ancient DNA (sedaDNA) is at the forefront of research in palaeoenvironmental reconstruction, although much remains unknown about the taphonomy of DNA in the environment.

In this talk Robin will describe the reconstruction of the palaeoecology of a river system from the Late Pleistocene to the late Holocene using sedaDNA from cores spanning the length of the river system and headwater area. The data allow the construction of a taphonomic model for DNA which allows us to determine which sediments are secure representing the original depositional environment. Secure sediments reveal the presence of several tree species such as Alnus, Quercus, Ulmus and Corylus over 16000 years ago, and thermal indicator tree species like Tilia several thousand years earlier than has been recorded for surrounding European areas. In this area we also detect the presence of Pterocarya, previously considered extinct since the Hoxnian. These observations are consistent with colonization from glacial refugia closer than the classic southern Europe refugia.