Elucidating recent history by tracing genetic affinity of three 16th century miners from Sweden

Objectives: Sala Silver Mine in central Sweden was an important manufacturer of silver from at least the 16th till the early 20th century, with production peaking in the 16th, mid 17th and 19th centuries. The job opportunities offered by the mine attracted people to the area resulting in the development of a small township with an associated cemetery in the vicinity of the mining center. People affiliated to the mine were buried on the cemetery for around 150 years. Written sources reveal that common criminal convicts from Sweden-Finland and war prisoners from the numerous wars fought by Sweden during the time were exploited in the mine, and some of them were likely buried on the cemetery. The cemetery has been excavated on several occasions and the recovered human remains were divided into two different groups based on burial custom, demography and biochemical results. One group was believed to contain war prisoners; the aim of this study was to produce and interpret genomic data from these individuals to test if their genetic ancestry is consistent with the hypothesis that they were non-locals. Materials: Teeth from seven different individuals were sampled for dentine. Results: Three of the analyzed teeth contained sufficient amounts of endogenous human DNA for the generation of genomic sequence data to a coverage of 0.04, 0.19 and 0.83, respectively. Discussion: The results show that despite seeming heterogeneity the three individuals grouped within the range of genetic variation of modern and contemporary Swedes, yielding no statistical support to the hypothesis that they were foreign captives. However, due to the lack of contemporary or modern Danish genomic data we cannot refute these individuals originated in Denmark which was suggested as one of possible sources of the 17th century Swedish prisoners of war.