Population genomics of the Viking world.

The maritime expansion of Scandinavian populations during the Viking Age (about AD 750-1050) was a far-flung transformation in world history1,2. Here we sequenced the genomes of 442 humans from archaeological sites across Europe and Greenland (to a median depth of about 1×) to understand the global influence of this expansion. We find the Viking period involved gene flow into Scandinavia from the south and east. We observe genetic structure within Scandinavia, with diversity hotspots in the south and restricted gene flow within Scandinavia. We find evidence for a major influx of Danish ancestry into England; a Swedish influx into the Baltic; and Norwegian influx into Ireland, Iceland and Greenland. Additionally, we see substantial ancestry from elsewhere in Europe entering Scandinavia during the Viking Age. Our ancient DNA analysis also revealed that a Viking expedition included close family members. By comparing with modern populations, we find that pigmentation-associated loci have undergone strong population differentiation during the past millennium, and trace positively selected loci-including the lactase-persistence allele of LCT and alleles of ANKA that are associated with the immune response-in detail. We conclude that the Viking diaspora was characterized by substantial transregional engagement: distinct populations influenced the genomic makeup of different regions of Europe, and Scandinavia experienced increased contact with the rest of the continent.

Shifting diet, shifting culture? A bioarchaeological approach to island dietary development on Iron-Age Öland, Baltic Sea.

OBJECTIVES: The diet and subsistence in Iron-Age Öland is debated as earlier studies and different archaeological sources seemingly provide conflicting interpretations. The objectives of this study are therefore to: (i) add new insights on diet and (ii) investigate the chronological variation in detail. It is common in studies of diet to investigate differences between datasets defined by archaeological periods (determined by artefact typology), but it is rare to explore whether these dietary changes are, in fact, well correlated with these temporal categories or not. MATERIALS AND METHODS: Stable isotope analysis of 108 individuals and 25 animals was used to interpret diet in comparison with data from earlier studies. Different values of TLE (Trophic Level Effect) for δ15 N were compared for interpretations of diet. Of the 108 individuals, 42 were subjected to 14 C analysis in this study. RESULTS: The isotopes from Iron-Age animals on Öland indicate that the local, contemporary ecology is specific. The human isotope values show chronological development both when pooled in chronological groups by typology and by more specific 14 C chronology. DISCUSSION: The new samples of animals as well as the use of 5‰ TLE for δ15 N values results in the diet reinterpreted as mainly domesticate-based, with at least two shifts in diet occurring in the Iron Age. The use of 14 C dates in connection with the stable isotope results indicates a dietary transition occurring between 200 BC and AD 200, a date range that spans two typologically determined time periods.

Virtual taphonomy: A new method integrating excavation and postprocessing in an archaeological context.

The objective of this paper was to integrate excavation and post-processing of archaeological and osteological contexts and material to enhance the interpretation of these with specific focus on the taphonomical aspects. A method was designed, Virtual Taphonomy, based on the use and integration of image-based 3D modeling techniques into a 3D GIS platform, and tested on a case study. Merging the 3D models and a database directly in the same virtual environment allowed the authors to fully integrate excavation and post-processing in a complex spatial analysis reconnecting contexts excavated on different occasions in the field process. The case study further demonstrated that the method enabled a deeper understanding of the taphonomic agents at work and allowed the construction of a more detailed interpretation of the skeletal remains than possible with more traditional methods. The method also proved to add transparency to the entire research process from field to post-processing and interpretation. Other benefits were the timesaving aspects in documentation, not only in the excavation process but also in post-processing without creating additional costs in material, as the equipment used is available in most archaeological excavations. The authors conclude that this methodology could be employed on a variety of investigations from archaeological to forensic contexts and add significant value in many different respects (for example, detail, objectivity, complexity, time-efficiency) compared to methods currently used.

Diverse variola virus (smallpox) strains were widespread in northern Europe in the Viking Age.

Smallpox, one of the most devastating human diseases, killed between 300 million and 500 million people in the 20th century alone. We recovered viral sequences from 13 northern European individuals, including 11 dated to ~600-1050 CE, overlapping the Viking Age, and reconstructed near-complete variola virus genomes for four of them. The samples predate the earliest confirmed smallpox cases by ~1000 years, and the sequences reveal a now-extinct sister clade of the modern variola viruses that were in circulation before the eradication of smallpox. We date the most recent common ancestor of variola virus to ~1700 years ago. Distinct patterns of gene inactivation in the four near-complete sequences show that different evolutionary paths of genotypic host adaptation resulted in variola viruses that circulated widely among humans.