Gotland in the 3rd millennium BC. Archaeogenetics, archaeology and cultural diversity
Recent technological advancements have allowed for in-depth genetic investigations of pre-historic humans (archaeogenetics) which have profoundly altered European archaeology. These studies give unique insights into the actual individuals who lived the lives we try to understand, and the genetic structure of pre-historic Europe has been revealed. However, more work is needed for the merging of the two fields, and for the results to reach mainstream archaeology.
This project aims to elucidate the demographic developments during the Middle and Late Neolithic transition in Scandinavia in the 3rd millennium BC, from the investigation of burials on the island of Gotland. This is a turbulent time that encompass the end of the TRB-, PWC-, and BAC cultures, and the introduction of the Late Neolithic culture. However, there are large knowledge gaps due to the lack of relevant burials on the island. Recent archive research has revealed 20 new burials with probable connection to this time-period. These will be contextualized from osteological analyses, radiocarbon dating, isotopic analyses for diet and mobility, and the archaeological reports. The individuals will be further investigated with state-of-the art population genetic analyses to explore the population demographic and cultural developments on the island in relation to the Baltic Sea area. This project will contextualize the archaeological developments for one of the strongest demographic shifts in Stone Age Europe.
Final report
The purpose and development of the project
The purpose of the project was to elucidate the population demographic and cultural developments, as well as investigate kinship and social structure during the turbulent multicultural 3rd Millennium Before the Current Era on Gotland.
The project was twofold; one part involved contextualization and investigation of burial typology from archive investigation and traditional archaeology. These burials were from museum collections excavated between 1902 - 1986. Specifically single and multiple flat grave burials and stone cist inhumations were chosen that either had been relatively dated based on the artefacts and/or burial typology or were in close connection to other known burial/sites associated with the earlier Funnelbeaker and Pitted Ware cultures. The aim was to, from new radiocarbon dating investigate if relative dating, based on the above-mentioned criteria, was sufficient to correctly determine the archaeological time-period of the burial. It was also to investigate and compare the chronology of different types of stone cist burials to set a timeline for their introduction to the island.
Unfortunately, the human skeletal remains from a few of the burials, excavated at the end of the 19th and beginning of the 20th centuries, originally intended to be analyzed, were missing (or misplaced) at the museums. Similarly, several of the artefacts (e.g. flint daggers) in the burials that were further studied had also been misplaced and could not be located. However, I was able to locate the skeletal remains from a “missing burial” excavated in 1954 belonging to Gotland Museum. It was mistakenly stored at the Swedish History Museum under the acquisition number for an Iron Age burial from the same location. The material has now been returned to Gotland Museum.
The second part of the project was to further contextualize specific Late Neolithic burials using multidisciplinary analyses. Traditional osteological analysis, together with radiocarbon dating and dietary analysis of carbon and nitrogen isotopes, allowed for the study of the people within these burials. Moreover, mobility analyses of strontium isotopes in enamel allowed for identification of first-generation migrants to the island. Furthermore, genetic analyses of the same individuals allowed for investigation of population demography, ancestry, and kinship, which then has been compared to previously published earlier, and contemporaneous individuals from different cultures around the Baltic Sea area and Scandinavia.
A brief description of the implementation
The start of the project was delayed due to the pandemic, and further delays during the first two years were affecting the progression and timeline. First, due to closed museums, and then to extremely long turnaround time for the radiocarbon dating analyses. A one-year extension was given for the final deadline after the halftime presentation in 2022. The delays have also affected the progress of the subsequent genetic analyses as several of the burials needed to be contextualized from osteology and radiocarbon dating prior to these analyses.
Several different types of burials were investigated here. In total, 22 burials were Accelerator Mass Spectrometry (AMS) radiocarbon dated. Seven new communal burials have been contextualized from osteology, and an additional 34 individuals were AMS dated, and IRMS-analyzed (Isotope-Ratio Mass Spectrometry) for 13C and 15N dietary isotopes. For the mobility analyses a total of 45 individuals and 64 teeth have been subjected to strontium (87Sr/86Sr) analysis with LA-MC-ICP-MS (Laser Ablation Multi-Collector Inductively Coupled Plasma Mass Spectrometry). Furthermore, a total of 80 samples have been tested for DNA, which resulted in 38 new individuals, with between 0.04 - 2.62 x genome-coverage, that are included in the downstream analyses.
The program's most significant results and discussion of the conclusions and new research questions
Many interesting results have been discovered in the project. As expected, several burials dated to other time periods than what had been suggested in the documentation. This shows that although some burials are correctly determined, some are not. It is therefore precarious to trust previous determinations based on relative dating or, as in the case of single inhumations without artefacts, using adjacent burials or sites as a template for the temporal and cultural affinity.
Moreover, the picture has become clearer regarding the progression and timing of the Late Neolithic transition on the island, the chronology of Late Neolithic burial typology, and mobility patterns over time. An unusual type of Late Neolithic stone cist burial has been discovered, and unexpected use of a typical Late Neolithic burial has also been found. Furthermore, pathogens, as well as osteological stress markers from habitual behaviors have been discovered in different contexts. These are further analyzed, and specifically the disease load of these individuals interred in the different types of megalithic burials is a new research question that arose during this project.
Dissemination of the research
Due to the above-mentioned delays, the investigations are still ongoing, and the results will be presented in several forthcoming peer-reviewed scientific publications presented open access (CC BY), and from national and international conferences during the coming years. After each publication all data will be deposited in relevant open repositories in Swedigarch (Swedish National Infrastructure for Digital Archaeology) and connected to the acquisition and site numbers at the museums and the Swedish National Heritage Board. The genetic data will be deposited in the European Nucleotide Archive (ENA).
Whether and how collaboration has occurred
1. A collaboration regarding microbial paleogenomics and ancient disease has been established with researchers at Dept. of Genomes and Genetics and the Dept. of Microbiology, Institut Pasteur, Paris, France.
2. The preservation of DNA in the bones on Gotland is very good, and samples for several individuals in this study yielded very high proportions of endogenous DNA content. These individuals have been further investigated in an international collaboration project involving epi-genetic analyses of high-coverage ancient genomes together with the Palaeogenomics group at Maximilian University, Munich, Germany, the Institute at Poznan University of Medical Sciences, Poland, and Mattias Jakobssons group, IOB, EBC, Uppsala University.
3. Collaborations regarding Late Neolithic migration patterns in Scandinavia and the spread of Indo-European language have been established with researchers in the RJ-financed LAMP project (Languages and myths of prehistory) at the Dept. of Linguistics, Stockholm University.
The purpose of the project was to elucidate the population demographic and cultural developments, as well as investigate kinship and social structure during the turbulent multicultural 3rd Millennium Before the Current Era on Gotland.
The project was twofold; one part involved contextualization and investigation of burial typology from archive investigation and traditional archaeology. These burials were from museum collections excavated between 1902 - 1986. Specifically single and multiple flat grave burials and stone cist inhumations were chosen that either had been relatively dated based on the artefacts and/or burial typology or were in close connection to other known burial/sites associated with the earlier Funnelbeaker and Pitted Ware cultures. The aim was to, from new radiocarbon dating investigate if relative dating, based on the above-mentioned criteria, was sufficient to correctly determine the archaeological time-period of the burial. It was also to investigate and compare the chronology of different types of stone cist burials to set a timeline for their introduction to the island.
Unfortunately, the human skeletal remains from a few of the burials, excavated at the end of the 19th and beginning of the 20th centuries, originally intended to be analyzed, were missing (or misplaced) at the museums. Similarly, several of the artefacts (e.g. flint daggers) in the burials that were further studied had also been misplaced and could not be located. However, I was able to locate the skeletal remains from a “missing burial” excavated in 1954 belonging to Gotland Museum. It was mistakenly stored at the Swedish History Museum under the acquisition number for an Iron Age burial from the same location. The material has now been returned to Gotland Museum.
The second part of the project was to further contextualize specific Late Neolithic burials using multidisciplinary analyses. Traditional osteological analysis, together with radiocarbon dating and dietary analysis of carbon and nitrogen isotopes, allowed for the study of the people within these burials. Moreover, mobility analyses of strontium isotopes in enamel allowed for identification of first-generation migrants to the island. Furthermore, genetic analyses of the same individuals allowed for investigation of population demography, ancestry, and kinship, which then has been compared to previously published earlier, and contemporaneous individuals from different cultures around the Baltic Sea area and Scandinavia.
A brief description of the implementation
The start of the project was delayed due to the pandemic, and further delays during the first two years were affecting the progression and timeline. First, due to closed museums, and then to extremely long turnaround time for the radiocarbon dating analyses. A one-year extension was given for the final deadline after the halftime presentation in 2022. The delays have also affected the progress of the subsequent genetic analyses as several of the burials needed to be contextualized from osteology and radiocarbon dating prior to these analyses.
Several different types of burials were investigated here. In total, 22 burials were Accelerator Mass Spectrometry (AMS) radiocarbon dated. Seven new communal burials have been contextualized from osteology, and an additional 34 individuals were AMS dated, and IRMS-analyzed (Isotope-Ratio Mass Spectrometry) for 13C and 15N dietary isotopes. For the mobility analyses a total of 45 individuals and 64 teeth have been subjected to strontium (87Sr/86Sr) analysis with LA-MC-ICP-MS (Laser Ablation Multi-Collector Inductively Coupled Plasma Mass Spectrometry). Furthermore, a total of 80 samples have been tested for DNA, which resulted in 38 new individuals, with between 0.04 - 2.62 x genome-coverage, that are included in the downstream analyses.
The program's most significant results and discussion of the conclusions and new research questions
Many interesting results have been discovered in the project. As expected, several burials dated to other time periods than what had been suggested in the documentation. This shows that although some burials are correctly determined, some are not. It is therefore precarious to trust previous determinations based on relative dating or, as in the case of single inhumations without artefacts, using adjacent burials or sites as a template for the temporal and cultural affinity.
Moreover, the picture has become clearer regarding the progression and timing of the Late Neolithic transition on the island, the chronology of Late Neolithic burial typology, and mobility patterns over time. An unusual type of Late Neolithic stone cist burial has been discovered, and unexpected use of a typical Late Neolithic burial has also been found. Furthermore, pathogens, as well as osteological stress markers from habitual behaviors have been discovered in different contexts. These are further analyzed, and specifically the disease load of these individuals interred in the different types of megalithic burials is a new research question that arose during this project.
Dissemination of the research
Due to the above-mentioned delays, the investigations are still ongoing, and the results will be presented in several forthcoming peer-reviewed scientific publications presented open access (CC BY), and from national and international conferences during the coming years. After each publication all data will be deposited in relevant open repositories in Swedigarch (Swedish National Infrastructure for Digital Archaeology) and connected to the acquisition and site numbers at the museums and the Swedish National Heritage Board. The genetic data will be deposited in the European Nucleotide Archive (ENA).
Whether and how collaboration has occurred
1. A collaboration regarding microbial paleogenomics and ancient disease has been established with researchers at Dept. of Genomes and Genetics and the Dept. of Microbiology, Institut Pasteur, Paris, France.
2. The preservation of DNA in the bones on Gotland is very good, and samples for several individuals in this study yielded very high proportions of endogenous DNA content. These individuals have been further investigated in an international collaboration project involving epi-genetic analyses of high-coverage ancient genomes together with the Palaeogenomics group at Maximilian University, Munich, Germany, the Institute at Poznan University of Medical Sciences, Poland, and Mattias Jakobssons group, IOB, EBC, Uppsala University.
3. Collaborations regarding Late Neolithic migration patterns in Scandinavia and the spread of Indo-European language have been established with researchers in the RJ-financed LAMP project (Languages and myths of prehistory) at the Dept. of Linguistics, Stockholm University.