Swerving north, south, east and west : An interdisciplinary case study on Roman Iron Age cairns on the coast of Ostrobothnia, Finland

Abstract

This interdisciplinary case study using archaeogenetics provides new perspectives into the Roman Iron Age cairns on the Ostrobothnian coast, the individuals buried within them and the Roman Iron Age migrations of Proto-Finnic speakers. Seven individuals from Raahe Tervakangas (0-400 CE), Pedersöre Esse-Högbacken (c. 200 CE) and Vöyri Latjineliden (200-800 CE) have been successfully sampled for ancient DNA (aDNA) and were studied alongside an unsuccessfully sampled individual from Latjineliden. The sites were chosen based on similar time frame and region and availability of genetic data. The individuals are some of the oldest samples that have yielded aDNA sequence data from Finland and the sampled DNA-data were analysed through several methods including PCA, F-statistics, sex determination and kinship analysis. All individuals were radiocarbon dated as well, although in the cases of Tervakangas and Latjineliden the results are unreliable as proven by calculating tectonic uplift and an observed pair of first-degree relatives. Both the archaeological and genetic data indicate that the individuals in question have connections to most cardinal directions. Through interdisciplinary analysis it is also possible to suggest that Proto-Finnic speaking migrants from the Baltic would have admixed with local populations in coastal Ostrobothnia by the younger Roman Iron Age. The older Roman Iron Age individual from Tervakangas, however, represents probable Proto-Saami speakers before the community began practicing agriculture. The interdisciplinary nature of this study has enabled deeper analysis of the individuals studied and sites and the results present new possible perspectives into the Roman Iron Age migrations.