1
|
Wittmann L, Kuehn C. The Demographic-Wealth model for cliodynamics. PLoS One 2024; 19:e0298318. [PMID: 38564574 PMCID: PMC10986950 DOI: 10.1371/journal.pone.0298318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2023] [Accepted: 01/18/2024] [Indexed: 04/04/2024] Open
Abstract
Cliodynamics is a still a relatively new research area with the purpose of investigating and modelling historical processes. One of its first important mathematical models was proposed by Turchin and called "Demographic-Fiscal Model" (DFM). This DFM was one of the first and is one of a few models that link population with state dynamics. In this work, we propose a possible alternative to the classical Turchin DFM, which contributes to further model development and comparison essential for the field of cliodynamics. Our "Demographic-Wealth Model" (DWM) aims to also model link between population and state dynamics but makes different modelling assumptions, particularly about the type of possible taxation. As an important contribution, we employ tools from nonlinear dynamics, e.g., existence theory for periodic orbits as well as analytical and numerical bifurcation analysis, to analyze the DWM. We believe that these tools can also be helpful for many other current and future models in cliodynamics. One particular focus of our analysis is the occurrence of Hopf bifurcations. Therefore, a detailed analysis is developed regarding equilibria and their possible bifurcations. Especially noticeable is the behavior of the so-called coexistence point. While changing different parameters, a variety of Hopf bifurcations occur. In addition, it is indicated, what role Hopf bifurcations may play in the interplay between population and state dynamics. There are critical values of different parameters that yield periodic behavior and limit cycles when exceeded, similar to the "paradox of enrichment" known in ecology. This means that the DWM provides one possible avenue setup to explain in a simple format the existence of secular cycles, which have been observed in historical data. In summary, our model aims to balance simplicity, linking to the underlying processes and the goal to represent secular cycles.
Collapse
Affiliation(s)
- Lukas Wittmann
- Department of Mathematics, School of Computation Information and Technology, Technical University of Munich, Garching, Germany
| | - Christian Kuehn
- Department of Mathematics, School of Computation Information and Technology, Technical University of Munich, Garching, Germany
| |
Collapse
|
2
|
Li W, Shen H, Huang Z, Yang H. Research on the Dynamical Behavior of Public Opinion Triggered by Rumor Based on a Nonlinear Oscillator Model. ENTROPY (BASEL, SWITZERLAND) 2023; 25:1614. [PMID: 38136494 PMCID: PMC10742507 DOI: 10.3390/e25121614] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2023] [Revised: 11/26/2023] [Accepted: 11/30/2023] [Indexed: 12/24/2023]
Abstract
In public opinion triggered by rumors, the authenticity of the information remains uncertain, and the main topic oscillates between diverse opinions. In this paper, a nonlinear oscillator model is proposed to demonstrate the public opinion triggered by rumors. Based on the model and actual data of one case, it is found that a continuous flow of new information about rumors acts as external forces on the system, probably leading to the chaotic behavior of public opinion. Moreover, similar features are observed in three other cases, and the same model is also applicable to these cases. Based on these results, it is shown that our model possesses generality, revealing the evolutionary trends of a certain type of public opinion in real-world scenarios.
Collapse
Affiliation(s)
| | - Huizhang Shen
- Antai College of Economics and Management, Shanghai Jiao Tong University, Shanghai 200030, China; (W.L.); (Z.H.); (H.Y.)
| | | | | |
Collapse
|
3
|
Alaimo LS, Ciaschini C, Mariani F, Cudlinova E, Postigliola M, Strangio D, Salvati L. Unraveling population trends in Italy (1921-2021) with spatial econometrics. Sci Rep 2023; 13:20358. [PMID: 37989838 PMCID: PMC10663467 DOI: 10.1038/s41598-023-46906-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 11/07/2023] [Indexed: 11/23/2023] Open
Abstract
Testing density-dependence and path-dependence in long-term population dynamics under differentiated local contexts contributes to delineate the changing role of socioeconomic forces at the base of regional disparities. Despite a millenary settlement history, such issue has been rarely investigated in Europe, and especially in highly divided countries such as those in the Mediterranean region. Using econometric modeling to manage spatial heterogeneity, our study verifies the role of selected drivers of population growth at ten times between 1921 and 2021 in more than 8000 Italian municipalities verifying density-dependent and path-dependent dynamics. Results of global and quantile (spatial) regressions highlight a differential impact of density and (lagged) population growth on demographic dynamics along the urban cycle in Italy. Being weakly significant in the inter-war period (1921-1951), econometric models totalized a high goodness-of-fit in correspondence with compact urbanization (1951-1981). Model's fit declined in the following decades (1981-2021) reflecting suburbanization and counter-urbanization. Density-dependence and path-dependence were found significant and, respectively, positive or negative, with compact urbanization, and much less intense with suburbanization and counter-urbanization. A spatial econometric investigation of density-dependent and path-dependent mechanisms of population dynamics provided an original explanation of metropolitan cycles, delineating the evolution of socioeconomic (local) systems along the urban-rural gradient.
Collapse
Affiliation(s)
- Leonardo Salvatore Alaimo
- Department of Social Sciences and Economics, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185, Rome, Italy.
| | - Clio Ciaschini
- Department of Social and Economic Sciences, Polytechnic University of Marche, Piazzale C. Martelli 8, 60121, Ancona, Italy
| | - Francesca Mariani
- Department of Social and Economic Sciences, Polytechnic University of Marche, Piazzale C. Martelli 8, 60121, Ancona, Italy
| | - Eva Cudlinova
- Department of Economics, University of South Bohemia, Branišovská 1645/31A, České Budějovice 2, 370 05, Ceske Budejovice, Czech Republic
| | - Michele Postigliola
- Department of Methods and Models for Economics, Territory and Finance, Faculty of Economics, Sapienza University of Rome, Via del Castro Laurenziano 9, 00161, Rome, Italy.
| | - Donatella Strangio
- Department of Methods and Models for Economics, Territory and Finance, Faculty of Economics, Sapienza University of Rome, Via del Castro Laurenziano 9, 00161, Rome, Italy.
| | - Luca Salvati
- Department of Methods and Models for Economics, Territory and Finance, Faculty of Economics, Sapienza University of Rome, Via del Castro Laurenziano 9, 00161, Rome, Italy.
| |
Collapse
|
4
|
Kondor D, Bennett JS, Gronenborn D, Antunes N, Hoyer D, Turchin P. Explaining population booms and busts in Mid-Holocene Europe. Sci Rep 2023; 13:9310. [PMID: 37291136 PMCID: PMC10250413 DOI: 10.1038/s41598-023-35920-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Accepted: 05/25/2023] [Indexed: 06/10/2023] Open
Abstract
Archaeological evidence suggests that the population dynamics of Mid-Holocene (Late Mesolithic to Initial Bronze Age, ca. 7000-3000 BCE) Europe are characterized by recurrent booms and busts of regional settlement and occupation density. These boom-bust patterns are documented in the temporal distribution of 14C dates and in archaeological settlement data from regional studies. We test two competing hypotheses attempting to explain these dynamics: climate forcing and social dynamics leading to inter-group conflict. Using the framework of spatially-explicit agent-based models, we translated these hypotheses into a suite of explicit computational models, derived quantitative predictions for population fluctuations, and compared these predictions to data. We demonstrate that climate variation during the European Mid-Holocene is unable to explain the quantitative features (average periodicities and amplitudes) of observed boom-bust dynamics. In contrast, scenarios with social dynamics encompassing density-dependent conflict produce population patterns with time scales and amplitudes similar to those observed in the data. These results suggest that social processes, including violent conflict, played a crucial role in the shaping of population dynamics of European Mid-Holocene societies.
Collapse
Affiliation(s)
| | | | | | | | - Daniel Hoyer
- Evolution Institute, Tampa, FL, USA
- George Brown College, Toronto, Canada
| | | |
Collapse
|
5
|
Vuorinen KEM, Oksanen T, Oksanen L, Vuorisalo T, Speed JDM. Why don't all species overexploit? OIKOS 2021. [DOI: 10.1111/oik.08358] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Katariina E. M. Vuorinen
- Dept of Natural History, NTNU Univ. Museum, Norwegian Univ. of Science and Technology Trondheim Norway
| | - Tarja Oksanen
- Dept of Arctic and Marine Biology, UiT, The Arctic Univ. of Norway, Campus Alta Alta Norway
- Dept of Biology, Ecology Section, Univ. of Turku Turku Finland
| | - Lauri Oksanen
- Dept of Arctic and Marine Biology, UiT, The Arctic Univ. of Norway, Campus Alta Alta Norway
- Dept of Biology, Ecology Section, Univ. of Turku Turku Finland
| | - Timo Vuorisalo
- Dept of Biology, Ecology Section, Univ. of Turku Turku Finland
| | - James D. M. Speed
- Dept of Natural History, NTNU Univ. Museum, Norwegian Univ. of Science and Technology Trondheim Norway
| |
Collapse
|
6
|
Lima M, Gayo EM, Latorre C, Santoro CM, Estay SA, Cañellas-Boltà N, Margalef O, Giralt S, Sáez A, Pla-Rabes S, Chr Stenseth N. Ecology of the collapse of Rapa Nui society. Proc Biol Sci 2020; 287:20200662. [PMID: 32576113 PMCID: PMC7329031 DOI: 10.1098/rspb.2020.0662] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Collapses of food producer societies are recurrent events in prehistory and have triggered a growing concern for identifying the underlying causes of convergences/divergences across cultures around the world. One of the most studied and used as a paradigmatic case is the population collapse of the Rapa Nui society. Here, we test different hypotheses about it by developing explicit population dynamic models that integrate feedbacks between climatic, demographic and ecological factors that underpinned the socio-cultural trajectory of these people. We evaluate our model outputs against a reconstruction of past population size based on archaeological radiocarbon dates from the island. The resulting estimated demographic declines of the Rapa Nui people are linked to the long-term effects of climate change on the island's carrying capacity and, in turn, on the ‘per-capita food supply’.
Collapse
Affiliation(s)
- M Lima
- Departamento de Ecología, Pontificia Universidad Católica de Chile, Santiago, Chile.,Center of Applied Ecology and Sustainability (CAPES), Pontificia Universidad Católica de Chile, Santiago, Chile
| | - E M Gayo
- Center of Applied Ecology and Sustainability (CAPES), Pontificia Universidad Católica de Chile, Santiago, Chile.,Center for Climate and Resilience Research (CR2), Santiago, Chile
| | - C Latorre
- Departamento de Ecología, Pontificia Universidad Católica de Chile, Santiago, Chile.,Centro UC del Desierto de Atacama, Pontificia Universidad Católica de Chile, Santiago, Chile.,Institute of Ecology and Biodiversity (IEB), Santiago, Chile
| | - C M Santoro
- Instituto de Alta Investigación, Universidad de Tarapacá, Arica, Chile
| | - S A Estay
- Center of Applied Ecology and Sustainability (CAPES), Pontificia Universidad Católica de Chile, Santiago, Chile.,Instituto de Ciencias Ambientales y Evolutivas, Universidad Austral de Chile, Valdivia, Chile
| | - N Cañellas-Boltà
- Institute of Earth Sciences Jaume Almera (ICTJA-CSIC), Lluís Solé Sabarís s/n, E-08028 Barcelona, Spain
| | - O Margalef
- Consejo Superior de Investigaciones Científicas, Global Ecology Unit CREAF-CSIC-UAB, 08193 Cerdanyola del Vallès, Catalonia, Spain.,Center for Ecological Research and Forestry Application (CREAF), E-08193 Cerdanyola del Vallès, Catalonia, Spain
| | - S Giralt
- Institute of Earth Sciences Jaume Almera (ICTJA-CSIC), Lluís Solé Sabarís s/n, E-08028 Barcelona, Spain
| | - A Sáez
- Department of Earth and Ocean Dynamics, Universitat de Barcelona, Marti i Franques s/n, E-08028 Barcelona, Spain
| | - S Pla-Rabes
- BABVE, Universitat Autònoma de Barcelona (UAB), Cerdanyola del Vallès 08193, Spain.,Center for Ecological Research and Forestry Application (CREAF), E-08193 Cerdanyola del Vallès, Catalonia, Spain
| | - N Chr Stenseth
- Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biosciences, University of Oslo, PO Box 1066, Blindern, 0316 Oslo, Norway
| |
Collapse
|
7
|
Population Dynamics and Agglomeration Factors: A Non-Linear Threshold Estimation of Density Effects. SUSTAINABILITY 2020. [DOI: 10.3390/su12062257] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Although Southern Europe is relatively homogeneous in terms of settlement characteristics and urban dynamics, spatial heterogeneity in its population distribution is still high, and differences across regions outline specific demographic patterns that require in-depth investigation. In such contexts, density-dependent mechanisms of population growth are a key factor regulating socio-demographic dynamics at various spatial levels. Results of a spatio-temporal analysis of the distribution of the resident population in Greece contributes to identifying latent (density-dependent) processes of metropolitan growth over a sufficiently long time interval (1961-2011). Identification of density-dependent patterns of population growth contributes to the analysis of socioeconomic factors underlying demographic divides, possibly distinguishing between the effects of population concentration and dispersion. Population growth rates were non-linearly correlated with population density, highlighting a positive (or negative) impact of urban concentration on demographic growth when population is lower (or higher) than a fixed threshold (2800 and 1300 inhabitants/km2 in 1961 and 2011, respectively). In a context of low population density (less than 20 inhabitants/km2), the relationship between density and growth was again negative, contrasting with the positive and linear relationship observed in denser contexts. This result evidences a sort of ‘depopulation’ trap that leads to accelerated population decline under a defined density threshold. An improved understanding of density-dependent mechanisms of population growth and decline contributes to rethinking strategies of sustainable development and social policies more adapted to heterogeneous regional contexts.
Collapse
|
8
|
Gurven MD, Davison RJ. Periodic catastrophes over human evolutionary history are necessary to explain the forager population paradox. Proc Natl Acad Sci U S A 2019; 116:12758-12766. [PMID: 31182596 PMCID: PMC6600907 DOI: 10.1073/pnas.1902406116] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The rapid growth of contemporary human foragers and steady decline of chimpanzees represent puzzling population paradoxes, as any species must exhibit near-stationary growth over much of their evolutionary history. We evaluate the conditions favoring zero population growth (ZPG) among 10 small-scale subsistence human populations and five wild chimpanzee groups according to four demographic scenarios: altered mean vital rates (i.e., fertility and mortality), vital rate stochasticity, vital rate covariance, and periodic catastrophes. Among most human populations, changing mean fertility or survivorship alone requires unprecedented alterations. Stochastic variance and covariance would similarly require major adjustment to achieve ZPG in most populations. Crashes could maintain ZPG in slow-growing populations but must be frequent and severe in fast-growing populations-more extreme than observed in the ethnographic record. A combination of vital rate alteration with catastrophes is the most realistic solution to the forager population paradox. ZPG in declining chimpanzees is more readily obtainable through reducing mortality and altering covariance. While some human populations may have hovered near ZPG under harsher conditions (e.g., violence or food shortage), modern Homo sapiens were equipped with the potential to rapidly colonize new habitats and likely experienced population fluctuations and local extinctions over evolutionary history.
Collapse
Affiliation(s)
- Michael D Gurven
- Integrative Anthropological Sciences, Department of Anthropology, Leonard and Gretchan Broom Center for Demography, University of California, Santa Barbara, CA 93106;
| | - Raziel J Davison
- Institute for Behavioral and Economic Research, University of California, Santa Barbara, CA 93106
| |
Collapse
|
9
|
Henderson K, Loreau M. An ecological theory of changing human population dynamics. PEOPLE AND NATURE 2019. [DOI: 10.1002/pan3.8] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Affiliation(s)
- Kirsten Henderson
- Centre for Biodiversity, Theory, and Modelling Theoretical and Experimental Ecology Station, CNRS Moulis France
| | - Michel Loreau
- Centre for Biodiversity, Theory, and Modelling Theoretical and Experimental Ecology Station, CNRS Moulis France
| |
Collapse
|
10
|
European Neolithic societies showed early warning signals of population collapse. Proc Natl Acad Sci U S A 2018; 113:9751-6. [PMID: 27573833 DOI: 10.1073/pnas.1602504113] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Ecosystems on the verge of major reorganization-regime shift-may exhibit declining resilience, which can be detected using a collection of generic statistical tests known as early warning signals (EWSs). This study explores whether EWSs anticipated human population collapse during the European Neolithic. It analyzes recent reconstructions of European Neolithic (8-4 kya) population trends that reveal regime shifts from a period of rapid growth following the introduction of agriculture to a period of instability and collapse. We find statistical support for EWSs in advance of population collapse. Seven of nine regional datasets exhibit increasing autocorrelation and variance leading up to collapse, suggesting that these societies began to recover from perturbation more slowly as resilience declined. We derive EWS statistics from a prehistoric population proxy based on summed archaeological radiocarbon date probability densities. We use simulation to validate our methods and show that sampling biases, atmospheric effects, radiocarbon calibration error, and taphonomic processes are unlikely to explain the observed EWS patterns. The implications of these results for understanding the dynamics of Neolithic ecosystems are discussed, and we present a general framework for analyzing societal regime shifts using EWS at large spatial and temporal scales. We suggest that our findings are consistent with an adaptive cycling model that highlights both the vulnerability and resilience of early European populations. We close by discussing the implications of the detection of EWS in human systems for archaeology and sustainability science.
Collapse
|
11
|
Suleimenova D, Bell D, Groen D. A generalized simulation development approach for predicting refugee destinations. Sci Rep 2017; 7:13377. [PMID: 29042598 PMCID: PMC5645318 DOI: 10.1038/s41598-017-13828-9] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2017] [Accepted: 09/27/2017] [Indexed: 11/16/2022] Open
Abstract
In recent years, global forced displacement has reached record levels, with 22.5 million refugees worldwide. Forecasting refugee movements is important, as accurate predictions can help save refugee lives by allowing governments and NGOs to conduct a better informed allocation of humanitarian resources. Here, we propose a generalized simulation development approach to predict the destinations of refugee movements in conflict regions. In this approach, we synthesize data from UNHCR, ACLED and Bing Maps to construct agent-based simulations of refugee movements. We apply our approach to develop, run and validate refugee movement simulations set in three major African conflicts, estimating the distribution of incoming refugees across destination camps, given the expected total number of refugees in the conflict. Our simulations consistently predict more than 75% of the refugee destinations correctly after the first 12 days, and consistently outperform alternative naive forecasting techniques. Using our approach, we are also able to reproduce key trends in refugee arrival rates found in the UNHCR data.
Collapse
Affiliation(s)
- Diana Suleimenova
- Brunel University London, Department of Computer Science, London, UB8 3PH, United Kingdom
| | - David Bell
- Brunel University London, Department of Computer Science, London, UB8 3PH, United Kingdom
| | - Derek Groen
- Brunel University London, Department of Computer Science, London, UB8 3PH, United Kingdom.
- University College London, Centre for Computational Science, London, WC1H 0AJ, United Kingdom.
| |
Collapse
|
12
|
Suleimenova D, Bell D, Groen D. A generalized simulation development approach for predicting refugee destinations. Sci Rep 2017; 7:13377. [PMID: 29042598 DOI: 10.1109/wsc.2017.8247870] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2017] [Accepted: 09/27/2017] [Indexed: 05/21/2023] Open
Abstract
In recent years, global forced displacement has reached record levels, with 22.5 million refugees worldwide. Forecasting refugee movements is important, as accurate predictions can help save refugee lives by allowing governments and NGOs to conduct a better informed allocation of humanitarian resources. Here, we propose a generalized simulation development approach to predict the destinations of refugee movements in conflict regions. In this approach, we synthesize data from UNHCR, ACLED and Bing Maps to construct agent-based simulations of refugee movements. We apply our approach to develop, run and validate refugee movement simulations set in three major African conflicts, estimating the distribution of incoming refugees across destination camps, given the expected total number of refugees in the conflict. Our simulations consistently predict more than 75% of the refugee destinations correctly after the first 12 days, and consistently outperform alternative naive forecasting techniques. Using our approach, we are also able to reproduce key trends in refugee arrival rates found in the UNHCR data.
Collapse
Affiliation(s)
- Diana Suleimenova
- Brunel University London, Department of Computer Science, London, UB8 3PH, United Kingdom
| | - David Bell
- Brunel University London, Department of Computer Science, London, UB8 3PH, United Kingdom
| | - Derek Groen
- Brunel University London, Department of Computer Science, London, UB8 3PH, United Kingdom.
- University College London, Centre for Computational Science, London, WC1H 0AJ, United Kingdom.
| |
Collapse
|
13
|
Hoggarth JA, Restall M, Wood JW, Kennett DJ. Drought and Its Demographic Effects in the Maya Lowlands. CURRENT ANTHROPOLOGY 2017. [DOI: 10.1086/690046] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
|
14
|
Lima M, Christie DA, Santoro MC, Latorre C. Coupled Socio-Environmental Changes Triggered Indigenous Aymara Depopulation of the Semiarid Andes of Tarapacá-Chile during the Late 19th-20th Centuries. PLoS One 2016; 11:e0160580. [PMID: 27560499 PMCID: PMC4999284 DOI: 10.1371/journal.pone.0160580] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2016] [Accepted: 07/21/2016] [Indexed: 11/25/2022] Open
Abstract
Socio-economic and environmental changes are well known causes of demographic collapse of agrarian cultures. The collapse of human societies is a complex phenomenon where historical and cultural dimensions play a key role, and they may interact with the environmental context. However, the importance of the interaction between socio-economic and climatic factors in explaining possible breakdowns in Native American societies has been poorly explored. The aim of this study is to test the role of socio-economic causes and rainfall variability in the collapse suffered by the Aymara people of the semiarid Andean region of Tarapacá during the period 1820–1970. Our motivation is to demonstrate that simple population dynamic models can be helpful in understanding the causes and relative importance of population changes in Andean agro-pastoral societies in responses to socio-environmental variability. Simple logistic models that combine the effects of external socio-economic causes and past rainfall variability (inferred from Gross Domestic Product [GDP] and tree-rings, respectively) were quite accurate in predicting the sustained population decline of the Aymara people. Our results suggest that the depopulation in the semiarid Tarapacá province was caused by the interaction among external socio-economic pressures given by the economic growth of the lowlands and demands for labor coupled with a persistent decline in rainfall. This study constitutes an example of how applied ecological knowledge, in particular the application of the logistic equation and theories pertaining to nonlinear population dynamics and exogenous perturbations, can be used to better understand major demographic changes in human societies.
Collapse
Affiliation(s)
- Mauricio Lima
- Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
- Center of Applied Ecology and Sustainability (CAPES), Santiago, Chile
- Laboratorio Internacional de Cambio Global (CSIC-PUC), Santiago, Chile
- * E-mail:
| | - Duncan A. Christie
- Laboratorio de Dendrocronología y Cambio Global, Instituto de Conservación, Biodiversidad y Territorio, Universidad Austral de Chile, Valdivia, Chile
- Center for Climate and Resilience Research (CR)2, Santiago, Chile
| | - M. Calogero Santoro
- Laboratorio de Arqueología y Paleoambiente, Instituto de Alta de Investigación, Universidad de Tarapacá, Arica, Chile
| | - Claudio Latorre
- Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
- Laboratorio Internacional de Cambio Global (CSIC-PUC), Santiago, Chile
- Centro del Desierto de Atacama, Pontificia Universidad Católica de Chile, Santiago, Chile
- Institute of Ecology & Biodiversity (IEB), Santiago, Chile
| |
Collapse
|
15
|
Alados CL, Errea P, Gartzia M, Saiz H, Escós J. Positive and negative feedbacks and free-scale pattern distribution in rural-population dynamics. PLoS One 2014; 9:e114561. [PMID: 25474704 PMCID: PMC4256442 DOI: 10.1371/journal.pone.0114561] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2014] [Accepted: 11/10/2014] [Indexed: 11/18/2022] Open
Abstract
Depopulation of rural areas is a widespread phenomenon that has occurred in most industrialized countries, and has contributed significantly to a reduction in the productivity of agro-ecological resources. In this study, we identified the main trends in the dynamics of rural populations in the Central Pyrenees in the 20th C and early 21st C, and used density independent and density dependent models and identified the main factors that have influenced the dynamics. In addition, we investigated the change in the power law distribution of population size in those periods. Populations exhibited density-dependent positive feedback between 1960 and 2010, and a long-term positive correlation between agricultural activity and population size, which has resulted in a free-scale population distribution that has been disrupted by the collapse of the traditional agricultural society and by emigration to the industrialized cities. We concluded that complex socio-ecological systems that have strong feedback mechanisms can contribute to disruptive population collapses, which can be identified by changes in the pattern of population distribution.
Collapse
Affiliation(s)
| | - Paz Errea
- Pyrenean Institute of Ecology (CSIC), Zaragoza, Spain
| | - Maite Gartzia
- Pyrenean Institute of Ecology (CSIC), Nuestra Señora de la Victoria s/n, Jaca, Huesca, Spain
| | - Hugo Saiz
- Pyrenean Institute of Ecology (CSIC), Zaragoza, Spain
| | - Juan Escós
- Department of Animal Production and Food Technology, Huesca Polytechnic School, Zaragoza University, Zaragoza, Spain
| |
Collapse
|
16
|
Downey SS, Bocaege E, Kerig T, Edinborough K, Shennan S. The neolithic demographic transition in Europe: correlation with juvenility index supports interpretation of the summed calibrated radiocarbon date probability distribution (SCDPD) as a valid demographic proxy. PLoS One 2014; 9:e105730. [PMID: 25153481 PMCID: PMC4143272 DOI: 10.1371/journal.pone.0105730] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2013] [Accepted: 07/28/2014] [Indexed: 11/18/2022] Open
Abstract
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.
Collapse
Affiliation(s)
- Sean S. Downey
- Department of Anthropology, University of Maryland, College Park, Maryland, United States of America
- Institute of Archaeology, University College London, London, United Kingdom
| | - Emmy Bocaege
- Institute of Archaeology, University College London, London, United Kingdom
| | - Tim Kerig
- Institute of Archaeology, University College London, London, United Kingdom
- Research Training Group 1878 “Archaeology of Pre-Modern Economies”, University of Cologne, Cologne, North-Rhine Westphalia, Germany
| | - Kevan Edinborough
- Institute of Archaeology, University College London, London, United Kingdom
| | - Stephen Shennan
- Institute of Archaeology, University College London, London, United Kingdom
| |
Collapse
|
17
|
Lima M. Climate change and the population collapse during the "Great Famine" in pre-industrial Europe. Ecol Evol 2014; 4:284-91. [PMID: 24558584 PMCID: PMC3925430 DOI: 10.1002/ece3.936] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2013] [Revised: 11/27/2013] [Accepted: 11/29/2013] [Indexed: 11/10/2022] Open
Abstract
Population dynamics, economy, and human demography started with Malthus, the idea that population growth is limited by resources and “positive checks” occur when population growth overshoots the available resources. In fact, historical evidence indicates that long-term climate changes have destabilized civilizations and caused population collapses via food shortages, diseases, and wars. One of the worst population collapses of human societies occurred during the early fourteenth century in northern Europe; the “Great Famine” was the consequence of the dramatic effects of climate deterioration on human population growth. Thus, part of my motivation was to demonstrate that simple theoretical-based models can be helpful in understanding the causes of population change in preindustrial societies. Here, the results suggest that a logistic model with temperature as a “lateral” perturbation effect is the key element for explaining the population collapse exhibited by the European population during the “Great Famine”.
Collapse
Affiliation(s)
- Mauricio Lima
- Department of Ecology, Pontificia Universidad Católica de Chile Casilla 114-D, Santiago, CP 6513677, Chile ; Laboratorio Internacional de Cambio Global, LINCG (CSIC-PUC) Santiago, CP 6513677, Chile
| |
Collapse
|
18
|
Simulating society transitions: standstill, collapse and growth in an evolving network model. PLoS One 2013; 8:e75433. [PMID: 24086530 PMCID: PMC3783390 DOI: 10.1371/journal.pone.0075433] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2013] [Accepted: 08/14/2013] [Indexed: 11/19/2022] Open
Abstract
We developed a model society composed of various occupations that interact with each other and the environment, with the capability of simulating three widely recognized societal transition patterns: standstill, collapse and growth, which are important compositions of society evolving dynamics. Each occupation is equipped with a number of inhabitants that may randomly flow to other occupations, during which process new occupations may be created and then interact with existing ones. Total population of society is associated with productivity, which is determined by the structure and volume of the society. We ran the model under scenarios such as parasitism, environment fluctuation and invasion, which correspond to different driving forces of societal transition, and obtained reasonable simulation results. This work adds to our understanding of societal evolving dynamics as well as provides theoretical clues to sustainable development.
Collapse
|
19
|
Lima M, Berryman AA. Positive and negative feedbacks in human population dynamics: future equilibrium or collapse? OIKOS 2011. [DOI: 10.1111/j.1600-0706.2010.19112.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|