Our species is defined and sustained by interactions and networks. In Paleolithic contexts, reconstructing interactions and networks is limited to inferences based on material culture or direct evidence of biological relatedness, but evidence on the latter in the form of human fossils is very rare. Still, archaeogenetic research can formulate supra-regional models for broad time periods based on only a few genomes by distinguishing ancient clades, but not to the level of interactions between human groups of particular cultural complexes. Recently, archaeological sediments and speleothems - karstic cave formations - have been revealed as a further genomic archive for past environments and past human populations initiating a new phase in archaeogenetic research. These new archives have the potential to greatly expand the archaeogenetic record as they stem from ubiquitous environmental sources and they do provide the spatial and temporal resolution to zoom into population dynamics at the group level. However, what this ancient DNA (aDNA) originates from and under what conditions it preserves over time are still open questions. The MicroStratDNA project places this paleogenomic data into a microstratigraphic framework, where individual depositional events are recorded in microscopic features, to overcome these problems and to provide high-resolution time series of population interactions. Using an interdisciplinary tool kit, the project is (I) reconstructing the source, origin, and depositional history of sedimentary and speleothem aDNA in archaeological contexts, (II) identifying ideal preservation contexts for this type of aDNA with a focus on in-field assessments and (III) extracting genomic time series from archaeological sediments and speleothems. We are applying this approach predominantly to Upper Paleolithic sites in Georgia to reconstruct the relatedness of the people using individual sites over time and across contemporaneous sites set against regional expressions of climate and paleoenvironment change.
