mtDNA analysis of human remains from an early Danish Christian cemetery

One of Denmark's earliest Christian cemeteries is Kongemarken, dating to around AD 1000-1250. A feature of early Scandinavian Christian cemeteries is sex segregation, with females buried on the northern sides and males on the southern sides. However, such separation was never complete; in the few early Christian cemeteries excavated in Scandinavia, there were always a few males placed on the north side, and some females on the south side. At Kongemarken, several males with juxtaposed females were found on the north side of the cemetery. Thus, to evaluate possible kinship relationships, and more general questions of population affinity, we analyzed mitochondrial DNA extracted from nine individuals excavated in two different areas within the cemetery: one male and four females from Area 1, and one male and three females from Area 2. Using stringent laboratory protocols, each individual was unequivocally assigned to a mitochondrial haplogroup. A surprising amount of haplogroup diversity was observed (Area 1: 1 U7 (male), 1 H, 1 I, 1 J, and 1 T2; Area 2: 2 H, 1 I, and 1 T, with one H being male); even the three subjects of haplogroup H were of different subtypes. This indicates that no subjects within each area were maternally related. The observed haplogroup, U7, while common in India and in western Siberian tribes, was not previously observed among present-day ethnic Scandinavians, and haplogroup I is rare (2%) in Scandinavia. These observations suggest that the individuals living in the Roskilde region 1,000 years ago were not all members of a tightly knit local population and comprised individuals with genetic links with populations that were from much farther away.