Demography of the Early Neolithic Population in Central Balkans: Population Dynamics Reconstruction Using Summed Radiocarbon Probability Distributions

Demographic dynamics between 5500 and 3500 calBP (3550-1550 BCE) in selected study regions of Central Europe and the role of regional climate influences

With their rich Late Neolithic to Early Bronze Age archives, the Circumharz region, the Czech Republic/Lower Austria region, and the Northern Alpine Foreland are well-suited for research on potential links between human activities and climate fluctuations of this period with pronounced archaeological changes. In this paper, we reconstruct the rate and density of the available 14C data from 5500 to 3500 calBP (3550-1550 BCE). We ask to what extent population patterns varied over time and space, and whether fluctuations in human populations and their activities varied with local/regional climate changes. To answer these questions, we have compiled an extensive list of published radiocarbon dates and created 14C sum calibrations for each region. We also compare population dynamics with local and regional palaeoclimate records derived from high-resolution speleothems. At the regional scale, the results suggest a causal relationship between regional climate and population trends. Climate and associated environmental changes were thus at least partly responsible for demographic trends. These results also allow us to question the motivation for the construction of so-called "Early Bronze Age princely tombs" in the Circumharz region during a period of population decline. Among other things, it can be argued that the upper echelons of society may have benefited from trade relations. However, this process was accompanied by ecological stress, a cooling of the winter climate, a decline in the total population and an increase in social inequality.

Spatially explicit paleogenomic simulations support cohabitation with limited admixture between Bronze Age Central European populations

The Bronze Age is a complex period of social, cultural and economic changes. Recent paleogenomic studies have documented a large and rapid genetic change in early Bronze Age populations from Central Europe. However, the detailed demographic and genetic processes involved in this change are still debated. Here we have used spatially explicit simulations of genomic components to better characterize the demographic and migratory conditions that may have led to this change. We investigated various scenarios representing the expansion of pastoralists from the Pontic steppe, potentially linked to the Yamnaya cultural complex, and their interactions with local populations in Central Europe, considering various eco-evolutionary factors, such as population admixture, competition and long-distance dispersal. Our results do not support direct competition but rather the cohabitation of pastoralists and farmers in Central Europe, with limited gene flow between populations. They also suggest occasional long-distance migrations accompanying the expansion of pastoralists and a demographic decline in both populations following their initial contact. These results link recent archaeological and paleogenomic observations and move further the debate of genomic changes during the early Bronze Age.

Feeding Babies at the Beginnings of Urbanization in Central Europe

Small ceramic vessels with spouts, from which liquid can be poured, became popular during the Late Bronze and Early Iron Ages in Central Europe (c. 1200–600 BC). Such feeding vessels represent a functional type and are highly variable in size, shape and decoration. Found both on settlements and within graves, their association with child burials suggest they might have been used to feed babies and small children. Combined lipid and isotope analysis was performed on 24 of these feeding vessels, with seven delivering interpretable results. Feeding vessels associated with child burials tend to deliver a ruminant milk signal, whereas other vessels were used to process ruminant and non-ruminant adipose fats. Here, we highlight the potential significance of feeding vessels as indicators of changing childcare practices during times of population increase, settlement nucleation and mobility, possibly involving out-sourcing the feeding of babies and small children to persons other than the mother.

The Neolithic Demographic Transition in the Central Balkans: population dynamics reconstruction based on new radiocarbon evidence

In this paper, we test the hypothesis of the Neolithic Demographic Transition in the Central Balkan Early Neolithic (6250-5300 BC) by applying the method of summed calibrated probability distributions to the set of more than 200 new radiocarbon dates from Serbia. The results suggest that there was an increase in population size after the first farmers arrived to the study area around 6250 BC. This increase lasted for approximately 250 years and was followed by a decrease in the population size proxy after 6000 BC, reaching its minimum around 5800 BC. This was followed by another episode of growth until 5600 BC when population size proxy rapidly declined, reaching the minimum again around 5500 BC. The reconstructed intrinsic growth rate value indicates that the first episode of growth might have been fuelled both by high fertility and migrations, potentially related to the effects of the 8.2 ky event. The second episode of population growth after 5800 BC was probably owing to the high fertility alone. It remains unclear what caused the episodes of population decrease. This article is part of the theme issue 'Cross-disciplinary approaches to prehistoric demography'.

Directly modelling population dynamics in the South American Arid Diagonal using 14C dates

Large anthropogenic ¹⁴C datasets are widely used to generate summed probability distributions (SPDs) as a proxy for past human population levels. However, SPDs are a poor proxy when datasets are small, bearing little relationship to true population dynamics. Instead, more robust inferences can be achieved by directly modelling the population and assessing the model likelihood given the data. We introduce the R package ADMUR which uses a continuous piecewise linear (CPL) model of population change, calculates the model likelihood given a ¹⁴C dataset, estimates credible intervals using Markov chain Monte Carlo, applies a goodness-of-fit test, and uses the Schwarz Criterion to compare CPL models. We demonstrate the efficacy of this method using toy data, showing that spurious dynamics are avoided when sample sizes are small, and true population dynamics are recovered as sample sizes increase. Finally, we use an improved ¹⁴C dataset for the South American Arid Diagonal to compare CPL modelling to current simulation methods, and identify three Holocene phases when population trajectory estimates changed from rapid initial growth of 4.15% per generation to a decline of 0.05% per generation between 10 821 and 7055 yr BP, then gently grew at 0.58% per generation until 2500 yr BP. This article is part of the theme issue 'Cross-disciplinary approaches to prehistoric demography'.

Living off the land: Terrestrial-based diet and dairying in the farming communities of the Neolithic Balkans

The application of biomolecular techniques to archaeological materials from the Balkans is providing valuable new information on the prehistory of the region. This is especially relevant for the study of the neolithisation process in SE Europe, which gradually affected the rest of the continent. Here, to answer questions regarding diet and subsistence practices in early farming societies in the central Balkans, we combine organic residue analyses of archaeological pottery, taxonomic and isotopic study of domestic animal remains and biomolecular analyses of human dental calculus. The results from the analyses of the lipid residues from pottery suggest that milk was processed in ceramic vessels. Dairy products were shown to be part of the subsistence strategies of the earliest Neolithic communities in the region but were of varying importance in different areas of the Balkan. Conversely, milk proteins were not detected within the dental calculus. The molecular and isotopic identification of meat, dairy, plants and beeswax in the pottery lipids also provided insights into the diversity of diet in these early Neolithic communities, mainly based on terrestrial resources. We also present the first compound-specific radiocarbon dates for the region, obtained directly from absorbed organic residues extracted from pottery, identified as dairy lipids.

Multi-proxy stable isotope analyses of dentine microsections reveal diachronic changes in life history adaptations, mobility, and tuberculosis-induced wasting in prehistoric Liguria (Finale Ligure, Italy, northwestern Mediterranean)

OBJECTIVE

To reconstruct breastfeeding and weaning practices, metabolic stress including tuberculosis-induced wasting, and residential mobility of children in Neolithic and Metal Ages to infer their local ecologies.

MATERIALS

Seven permanent teeth from individuals dated to the Neolithic, Copper, Bronze, and Iron Ages buried in nearby caves in western Liguria, Italy.

METHODS

Carbon, nitrogen, and sulfur stable isotope analyses on dentine microsections. Tooth maturation was used to calculate age at death.

RESULTS

Two Neolithic children present longer pattern of weaning and appear to have been weaned using animal protein in contrast to the earlier weaning of Metal Ages children, which were probably weaned with vegetable resources. Sulfur isotopes suggest local origin of Neolithic and Cooper Age children, and non-local origins for Bronze and Iron Age children. Intense catabolism in the last two years is apparent in the adolescent with tuberculosis.

CONCLUSIONS

Shortening in weaning patterns during the Metal Ages are likely driven by the intensification of agricultural practices and cultivation of new crops during Bronze and Iron Ages. Neolithic food choices and delayed weaning patterns may represent one of the strategies to maximize growth and immune potential in a local economy/ecology with high-infectious load. Tuberculosis was a chronic and long-lasting disease.

SIGNIFICANCE

The first combined carbon, nitrogen, and sulfur analysis on prehistoric dentine microsections revealing changing human life history adaptations within the same region.

LIMITATIONS

Small sample size.

SUGGESTIONS FOR FURTHER RESEARCH

Increase the sulfur isotope dataset, use new EA-IRMS equipment, and provide data on amino acid to better define weaning food composition.

Tracing long-term demographic changes: The issue of spatial scales

This paper deals with the analysis of long-term changes in population densities at the regional and macro-regional scale and in the density of metapopulations. The following issues concerning estimations are addressed: chronological resolution of demographic changes, estimation of the weight of values for population density in order to transform the initial values included in the sample into the values that may be compared with each other at the regional scale, calibration of the transformed values into real population densities, and the estimation of the weight of values for population density at the scales of macro-regions and for the density of metapopulations. The proposed methods are tested on demographic changes in Central Europe, Southern Scandinavia, Southeastern Europe, and the Near East. The obtained results represent major trends in demographic development, while the proposed methodology could also be applied in other wide-scale demographic analyses.

Amplitude of travelling front as inferred from 14C predicts levels of genetic admixture among European early farmers

Large radiocarbon datasets have been analysed statistically to identify, on the one hand, the dynamics and tempo of dispersal processes and, on the other, demographic change. This is particularly true for the spread of farming practices in Neolithic Europe. Here we combine the two approaches and apply them to a new, extensive dataset of 14,535 radiocarbon dates for the Mesolithic and Neolithic periods across the Near East and Europe. The results indicate three distinct demographic regimes: one observed in or around the centre of farming innovation and involving a boost in carrying capacity; a second appearing in regions where Mesolithic populations were well established; and a third corresponding to large-scale migrations into previously essentially unoccupied territories, where the travelling front is readily identified. This spatio-temporal patterning linking demographic change with dispersal dynamics, as displayed in the amplitude of the travelling front, correlates and predicts levels of genetic admixture among European early farmers.