Periodic Reporting for period 4 - PALEoRIDER (Human health and migration in prehistory)
Okres sprawozdawczy: 2022-10-01 do 2023-03-31
Even before the recent COVID-19 related pandemic, human health and mobility were central topics in today’s media, and of constant significance to government agencies as well as most pertinent to current European affairs, as they directly affect human societies, past present and future. The PALEoRIDER project investigated the role of human migration, individual and group mobility, the rise of infectious diseases, and their interplay in the formation of Europe. At present, we can only record the current status, but – most crucially – we lack a temporal perspective that allows us to characterise the transformative effects that migrations, expansions, mobility and communicable diseases had on prehistoric societies. A critical understanding of these factors in Europe’s prehistory, the evolutionary relationships between human and animal hosts and pathogens, cause and effect of past exposure to pathogens, infectious diseases, and the adaptability to varying (human-made) environments and changing climates is of paramount importance, as it can inform future directions in human health and sustainability.
Ancient human DNA data provides crucial time-stamped snapshots for the reconstruction of human genetic history. Expanding this diachronic approach in Europe, PALEoRIDER generated detailed transects through time backed by archaeological and anthropological contexts to observe genetic changes in temporal cohorts over time. The ultimate goal was to compare periods of genetic continuity or discontinuity with periods of cultural, ecological and climatic changes and the presence/absence of pathogens to understand the role of humans as part of a continuous feedback loop. PALEoRIDER has contributed high quality ancient genomic data to the human and pathogen aDNA community. With this wealth of ancient genomic data it was possible to move from broad brush strokes to regionally nuanced views. We focussed on objectives that enabled us to understand human population structure and human mobility, pathogen detection, human-pathogen co-evolution, ecology and epidemiological modelling.
The attested transformative changes in Europe’s prehistory provided an ideal test scenario for questions that are related to human mobility, adaptability and susceptibility to infectious diseases in the past.
Ancient human DNA data provides crucial time-stamped snapshots for the reconstruction of human genetic history. Expanding this diachronic approach in Europe, PALEoRIDER generated detailed transects through time backed by archaeological and anthropological contexts to observe genetic changes in temporal cohorts over time. The ultimate goal was to compare periods of genetic continuity or discontinuity with periods of cultural, ecological and climatic changes and the presence/absence of pathogens to understand the role of humans as part of a continuous feedback loop. PALEoRIDER has contributed high quality ancient genomic data to the human and pathogen aDNA community. With this wealth of ancient genomic data it was possible to move from broad brush strokes to regionally nuanced views. We focussed on objectives that enabled us to understand human population structure and human mobility, pathogen detection, human-pathogen co-evolution, ecology and epidemiological modelling.
The attested transformative changes in Europe’s prehistory provided an ideal test scenario for questions that are related to human mobility, adaptability and susceptibility to infectious diseases in the past.
PALEoRIDER generated genomic data from ~1500 individuals from key sites in prehistoric Europe that span the chronological horizon from the 5th to the 2nd millennium BCE, resulting in good quality genome-wide data for >1000 prehistoric individuals. This data is fully compatible with other ancient and modern-day population genetic data and thus constitutes a substantial contribution to the aDNA community. By applying a new standard procedures for the parallel detection of endogenous human and pathogen DNA, we produced time transect in various regions of Europe, resulting in a time-stamped record of the states before, during and after critical events, which were reconciled with archaeological contexts. We also generated hundreds of new radiocarbon dates, which are a critical resource for the refinement of regional archaeological chronologies.
Generating a regionally nuanced account of the dynamic shifts in Europe's prehistory was the main focus of the PALEoRIDER project. PALEoRIDER generated time transect data, which allowed pan-European comparisons and is available via public, international data repositories. At the time of this project report 95% of the datasets of sub-projects are completed and/or fully contextualised, resulting in over a dozen high-profile publications, and the team members presented these results at various international conferences and/or internal workshops with collaboration partners.
PALEoRIDER targeted the transitions from the Eneolithic or Copper Age to the Bronze Age in various regions spanning from the North Caucasus in the East to southern Iberia in the West. The presence, expansion, and distinction between genetic ‘steppe’ and ‘forest steppe’ ancestry, primarily associated with pastoralist groups from the Eurasian steppe zones constituted a prominent feature. By studying zones of early contact and exchange between late farming and pastoralist groups also through the study of dairy proteins in dental calculus, we could shed light of the formative periods and economic changes during the 4th millennium BCE, which enabled the economic exploitation of the steppe zone and establishment of nomadic pastoralism as main subsistence strategy, which in the 3rd millennium BCE ultimately led to an expansion of these groups. Importantly, we observe that these processes had led to further transformations of the genetic and social structures in central and western parts of Europe.
Overall ,we documented an unprecedented level of dynamism across all time transects in Europe. We find that the expansion of steppe-related ancestry across Europe from the East, previously seen as a unified turnover event of the early 3rd millennium BCE, involved two or more streams with regional differentiation and variable timing, linked to varying population densities and socio-economic characteristic of the prehistoric societies involved. In the centuries following these expansions, we observe a complex interplay of various groups, indicating a long process of assimilation and continuous population dynamics. Intra-site studies estimating biological relatedness and uniparentally inherited lineages revealed striking patterns of virilocality and patrilineality alongside a strong reduction in Y-diversity, which suggest isolated mating networks under strict social norms. This pattern is dissolved in the 2nd millennium BCE in line with new burial customs and potentially reformed social organisation.
With respect to pathogens as potential driver or critical parameter, the PALEoRIDER project was able to contribute a large number of positive cases, corroborating previous evidence for the presence of a range of pathogens, in particular two early forms of the plague-causing agent of Yersinia pestis during the early Bronze Age alone. The regular detection and presence of other pathogens such as Salmonella enterica and recent advances in the detection of prehistoric viruses such as Hepatitis B (HBV) added further to the complex entanglement of human-pathogen interaction in parallel/contrast to human agency alone.
Generating a regionally nuanced account of the dynamic shifts in Europe's prehistory was the main focus of the PALEoRIDER project. PALEoRIDER generated time transect data, which allowed pan-European comparisons and is available via public, international data repositories. At the time of this project report 95% of the datasets of sub-projects are completed and/or fully contextualised, resulting in over a dozen high-profile publications, and the team members presented these results at various international conferences and/or internal workshops with collaboration partners.
PALEoRIDER targeted the transitions from the Eneolithic or Copper Age to the Bronze Age in various regions spanning from the North Caucasus in the East to southern Iberia in the West. The presence, expansion, and distinction between genetic ‘steppe’ and ‘forest steppe’ ancestry, primarily associated with pastoralist groups from the Eurasian steppe zones constituted a prominent feature. By studying zones of early contact and exchange between late farming and pastoralist groups also through the study of dairy proteins in dental calculus, we could shed light of the formative periods and economic changes during the 4th millennium BCE, which enabled the economic exploitation of the steppe zone and establishment of nomadic pastoralism as main subsistence strategy, which in the 3rd millennium BCE ultimately led to an expansion of these groups. Importantly, we observe that these processes had led to further transformations of the genetic and social structures in central and western parts of Europe.
Overall ,we documented an unprecedented level of dynamism across all time transects in Europe. We find that the expansion of steppe-related ancestry across Europe from the East, previously seen as a unified turnover event of the early 3rd millennium BCE, involved two or more streams with regional differentiation and variable timing, linked to varying population densities and socio-economic characteristic of the prehistoric societies involved. In the centuries following these expansions, we observe a complex interplay of various groups, indicating a long process of assimilation and continuous population dynamics. Intra-site studies estimating biological relatedness and uniparentally inherited lineages revealed striking patterns of virilocality and patrilineality alongside a strong reduction in Y-diversity, which suggest isolated mating networks under strict social norms. This pattern is dissolved in the 2nd millennium BCE in line with new burial customs and potentially reformed social organisation.
With respect to pathogens as potential driver or critical parameter, the PALEoRIDER project was able to contribute a large number of positive cases, corroborating previous evidence for the presence of a range of pathogens, in particular two early forms of the plague-causing agent of Yersinia pestis during the early Bronze Age alone. The regular detection and presence of other pathogens such as Salmonella enterica and recent advances in the detection of prehistoric viruses such as Hepatitis B (HBV) added further to the complex entanglement of human-pathogen interaction in parallel/contrast to human agency alone.
The size of the dataset had quickly grown beyond the number of individuals what was originally anticipated and the attention to completion of chronologically gapless or regionally coherent time transects formed a very powerful framework. The application of DNA capture techniques has proven to be a key factor in the successful retrieval of genome-wide data, allowing to reach sufficiently large cohort sizes, which enabled meaningful frequency-based estimates of allele shifts over time.
Further, we included a number of intra-site kinship studies, which allowed us to study social and biological kinship structures of Neolithic, Copper Age and Early Bronze Age groups.
We also discovered a large than anticipated number of pathogen-positive cases, which resulted in a body of data that we will utilise in joint continuous efforts at the department of Archaeogenetics at the MPI-EVA beyond the duration of the project.
Further, we included a number of intra-site kinship studies, which allowed us to study social and biological kinship structures of Neolithic, Copper Age and Early Bronze Age groups.
We also discovered a large than anticipated number of pathogen-positive cases, which resulted in a body of data that we will utilise in joint continuous efforts at the department of Archaeogenetics at the MPI-EVA beyond the duration of the project.