European Neolithic societies showed early warning signals of population collapse (original) (raw)
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A global dynamic model for the Neolithic transition
Climatic Change, 2003
During the Holocene strong gradients in the distribution of technology including subsistence ways emerged on a global scale. These patterns were further amplified in historic times and are still visible through worldwide differences in national wealth. In order to evaluate major factors responsible for the shift from foraging to food production we here employ quantitative methods by developing a deterministic but simple model. After compiling existing maps of potential vegetation at 5000 BP the inhabited world is split into 197 regions with homogeneous environmental conditions. Suitable variables for the macro-economic and cultural development in the Neolithic period are found to be farming to hunting-gathering ratio, number of agricultural economies and a technological development index. The model explicitly describes economic adaptation, growth and migration of human populations together with the spread of their cultural characteristics; it accounts for over- exploitation of natural resources, crowding mortality and the climate variability on a millennium scale. In a thorough model validation region specific trajectories are compared to archaeological evidence revealing a high correspondence. Major parts of the known sequence of Neolithic centers including the timing differences are robustly reproduced. A series of known problems in prehistory is discussed comprising the lag between domestication and full scale farming, the off-leveling of the technological boost following the transition, the emergence of distinct migration waves and sensitiv- ity to climate fluctuations. Not mere population pressure but continuous innovation and competition between subsistence strategies is identified as a prime mover of agricultural development. The results suggest that few aspects of biogeography may have determined the observed continental gradients in the number of domesticable species ultimately leading to an increasing differentiation in technology and demography.
In a previous study we presented a new method that used summed probability distributions (SPD) of radiocarbon dates as a proxy for population levels, and Monte-Carlo simulation to test the significance of the observed fluctuations in the context of uncertainty in the calibration curve and archaeological sampling. The method allowed us to identify periods of significant short-term population change, caveated with the fact that around 5% of these periods were false positives. In this study we present an improvement to the method by applying a criterion to remove these false positives from both the simulated and observed distributions, resulting in a substantial improvement to both its sensitivity and specificity. We also demonstrate that the method is extremely robust in the face of small sample sizes. Finally we apply this improved method to radiocarbon datasets from 12 European regions, covering the period 8000 to 4000 BP. As in our previous study, the results reveal a boom-bust pattern for most regions, with population levels rising rapidly after the local arrival of farming, followed by a crash to levels much lower than the peak. The prevalence of this phenomenon, combined with the dissimilarity and lack of synchronicity in the general shapes of the regional SPDs, supports the hypothesis of endogenous causes.
Abstract In a previous study we presented a new method that used summed probability distributions (SPD) of radiocarbon dates as a proxy for population levels, and Monte-Carlo simulation to test the significance of the observed fluctuations in the context of uncertainty in the calibration curve and archaeological sampling. The method allowed us to identify periods of significant short-term population change, caveated with the fact that around 5% of these periods were false positives. In this study we present an improvement to the method by applying a criterion to remove these false positives from both the simulated and observed distributions, resulting in a substantial improvement to both its sensitivity and specificity. We also demonstrate that the method is extremely robust in the face of small sample sizes. Finally we apply this improved method to radiocarbon datasets from 12 European regions, covering the period 8000 to 4000 BP. As in our previous study, the results reveal a boom-bust pattern for most regions, with population levels rising rapidly after the local arrival of farming, followed by a crash to levels much lower than the peak. The prevalence of this phenomenon, combined with the dissimilarity and lack of synchronicity in the general shapes of the regional SPDs, supports the hypothesis of endogenous causes.
2004
A signal of major demographic change was detected from a palaeoanthropologicaldatabase of 68 Meso-Neolithic cemeteries in Europe (reduced to 36 due to a sampling bias). The signal is characteriyed by a relatively abrupt change in the proportion of immature skeletons (aged 5-19 years), relative to all buried skeletons (5 years +). From the Meso to the Neolithic, the proportion rose from approximately 20% to 30%. This change reflects a noticeable increase in the birth rate over a duration of about 500-700 years, and is referred to as the Neolithic Demographic Transition (NDT). Another category of independent archaeological data, on enclosures (N =694), which are interpreted as a response to population growth within the social area, reveals a similar signal at the same tempo. If this is a true signal, we should expect it to be detected also in all the independent centresof agricultural invention worldwide. The NDT is at the historical root of the pre-industrial populations that would gradually spread across the Earthand which are now rapidly disappearing.
Analysis of the proportion of immature skeletons recovered from European prehistoric cemeteries has shown that the transition to agriculture after 9000 BP triggered a long-term increase in human fertility. Here we compare the largest analysis of European cemeteries to date with an independent line of evidence, the summed calibrated date probability distribution of radiocarbon dates (SCDPD) from archaeological sites. Our cemetery reanalysis confirms increased growth rates after the introduction of agriculture; the radiocarbon analysis also shows this pattern, and a significant correlation between both lines of evidence confirms the demographic validity of SCDPDs. We analyze the areal extent of Neolithic enclosures and demographic data from ethnographically known farming and foraging societies and we estimate differences in population levels at individual sites. We find little effect on the overall shape and precision of the SCDPD and we observe a small increase in the correlation with the cemetery trends. The SCDPD analysis supports the hypothesis that the transition to agriculture dramatically increased demographic growth, but it was followed within centuries by a general pattern of collapse even after accounting for higher settlement densities during the Neolithic. The study supports the unique contribution of SCDPDs as a valid demographic proxy for the demographic patterns associated with early agriculture.
Quaternary International, 2017
Inferred European Holocene population size exhibits large fluctuations, particularly around the onset of farming. We attempt to find explanations for these fluctuations by employing the concept of cycling, especially that of the Adaptive Cycle. We base our analysis on chronologically and chorologically highly resolved ceramic and site data from the Linear Pottery culture (Germ. Linearbandkermik) of the early Neolithic of southwestern Central Europe. Typological seriation with dendrochronological anchor dates provides the age model for these data. Ceramic motifs are analysed with respect to the temporally changing diversity in decoration. The temporal sequence of major decoration motifs is interpreted as an indicator of social diversity: when stylistic diversity is low, social diversity is low and vice versa. The sequence of secondary decoration motifs is interpreted in terms of individual lineage emphasis: when this diversity is low, there is strong emphasis on individual lineage and vice versa. The diversity time series are complemented by a relative population size indicator derived from the count of occupational features. Diversity and population size share a shape that is typical for (part of) an Adaptive Cycle, and they differ in their positioning on the time axisdthey are time-lagged. By relating the different curves to the (metaphorical) stages of the Adaptive Cycle, we find that these cycles progress at non-identical speed in different aspects of a social system. By relating the social dynamics to well-dated and highly resolved climate fluctuation records, we find evidence that severe climate excursions shaped the location of tipping points in the social system and that these social tipping points precede inferred population decline by several generations.
Testing the Hypothesis of a Worldwide Neolithic Demographic Transition
Current Anthropology, 2006
The signal of a major demographic change characterized by a relatively abrupt increase in the proportion of immature skeletons has been detected in a paleoanthropological database of 38 Mesolithic-Neolithic cemeteries from Europe and North Africa. From the Mesolithic to the Neolithic, the proportion of immature skeletons increases by 20-30% over a period of 500-700 years, indicating a notable increase in the crude birth rate. This shift has been called the Neolithic demographic transition. A similar signal has been detected in an independent set of archaeological data, namely, enclosures. This paper presents results from a sample of 62 cemeteries in North America (7,755 BP-350 BP) that point to the same transition over a period of 600-800 years. The signal of a Neolithic demographic transition has been detected in a paleoanthropological database of Mesolithic-Neolithic cemeteries in Europe and North Africa (Bocquet-Appel 2002; Bocquet-Appel and Paz de Miguel Ibáñez 2002). The database represents a time-space sample of a nonconventional marker, the proportion of immature skeletons (aged 5-19 years) in cemeteries. In a growing population the proportion of immature individuals (dead or alive) is high, while in a declining population it is low (McCaa 2000; Johansson and Horowitz 1986; Sattenspiel and Harpending 1983). The signal of the transition is characterized by a relatively abrupt increase in the proportion of immature skeletons; from the Mesolithic to the Neolithic, the proportion increases by 20-30%. An independent archaeological marker of demographic growth the chronological variation in the frequency of some 700 enclosures and enclosure systems, has revealed a similar signal (Bocquet-Appel and Dubouloz 2004). The link between demographic growth and enclosure frequency is based on the hypothesis that the number of collective buildings increases as the population grows. The detection of the signal in Europe has provided grounds for a prediction regarding its worldwide impact: if a Neolithic demographic transition occurred in Europe, it must also have happened in all the independent centers of agricultural invention in the
Analysis of the proportion of immature skeletons recovered from European prehistoric cemeteries has shown that the transition to agriculture after 9000 BP triggered a long-term increase in human fertility. Here we compare the largest analysis of European cemeteries to date with an independent line of evidence, the summed calibrated date probability distribution of radiocarbon dates (SCDPD) from archaeological sites. Our cemetery reanalysis confirms increased growth rates after the introduction of agriculture; the radiocarbon analysis also shows this pattern, and a significant correlation between both lines of evidence confirms the demographic validity of SCDPDs. We analyze the areal extent of Neolithic enclosures and demographic data from ethnographically known farming and foraging societies and we estimate differences in population levels at individual sites. We find little effect on the overall shape and precision of the SCDPD and we observe a small increase in the correlation with the cemetery trends. The SCDPD analysis supports the hypothesis that the transition to agriculture dramatically increased demographic growth, but it was followed within centuries by a general pattern of collapse even after accounting for higher settlement densities during the Neolithic. The study supports the unique contribution of SCDPDs as a valid demographic proxy for the demographic patterns associated with early agriculture.
PLoS One
Analysis of the proportion of immature skeletons recovered from European prehistoric cemeteries has shown that the transition to agriculture after 9000 BP triggered a long-term increase in human fertility. Here we compare the largest analysis of European cemeteries to date with an independent line of evidence, the summed calibrated date probability distribution of radiocarbon dates (SCDPD) from archaeological sites. Our cemetery reanalysis confirms increased growth rates after the introduction of agriculture; the radiocarbon analysis also shows this pattern, and a significant correlation between both lines of evidence confirms the demographic validity of SCDPDs. We analyze the areal extent of Neolithic enclosures and demographic data from ethnographically known farming and foraging societies and we estimate differences in population levels at individual sites. We find little effect on the overall shape and precision of the SCDPD and we observe a small increase in the correlation with the cemetery trends. The SCDPD analysis supports the hypothesis that the transition to agriculture dramatically increased demographic growth, but it was followed within centuries by a general pattern of collapse even after accounting for higher settlement densities during the Neolithic. The study supports the unique contribution of SCDPDs as a valid demographic proxy for the demographic patterns associated with early agriculture.
Resilience in the Neolithic: how people may have mitigated environmental change in prehistory
2013
Neolithic populations in Central Europe lived in a world of dynamic climate change. This paper explores human-environmental interactions in light of local environmental changes linked to human activity and small-scale climate change, with a case study from the 2011–12 investigations at two small early Late Neolithic settlements (c. 5000 BC) set along palaeomeanders of the Körös River in Békés County, Hungary. During the course of the Neolithic, this region saw complex development in social and settlement organization, including the nucleation of populations in large settlements and the continued reoccupation of living space. Utilizing archaeological and environmental data, we tackle the question of why these communities adopted different settlement systems, whether they maintained other cultural traditions, and how these choices may reflect efforts to mitigate environmental change. Historical ecology and the related concept of resiliency provide a conceptual approach to understanding the ways that human societies and the environment affect each other. By cultural resiliency, we mean the ability of a society to maintain and develop identity, knowledge and ways of making a living, despite challenges and disturbances, by resisting damage and recovering quickly. In this case, we speculate about ways that Neolithic populations on the Great Hungarian Plain triggered some kinds of environmental change, and how they coped with the combination of these and naturally occurring changes in palaeohydrology.