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Global hunter-gatherer population densities constrained by influence of seasonality on diet composition

Abstract

The dependence of hunter-gatherers on local net primary production (NPP) to provide food played a major role in shaping long-term human population dynamics. Observations of contemporary hunter-gatherers have shown an overall correlation between population density and annual NPP but with a 1,000-fold variation in population density per unit NPP that remains unexplained. Here, we build a process-based hunter-gatherer population model embedded within a global terrestrial biosphere model, which explicitly addresses the extraction of NPP through dynamically allocated hunting and gathering activities. The emergent results reveal a strong, previously unrecognized effect of seasonality on population density via diet composition, whereby hunter-gatherers consume high fractions of meat in regions where growing seasons are short, leading to greatly reduced population density due to trophic inefficiency. This seasonal carnivory bottleneck largely explains the wide variation in population density per unit NPP and questions the prevailing usage of annual NPP as the proxy of carrying capacity for ancient humans. Our process-based approach has the potential to greatly refine our understanding of dynamical responses of ancient human populations to past environmental changes.

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Fig. 1: Contemporary hunter-gatherer population density versus net primary production.
Fig. 2: Schematic of FORGE, coupled to the ORCHIDEE global terrestrial biosphere model.
Fig. 3: Modelled population density and time allocation.
Fig. 4: Meat fraction of the diet controls ΦNPP.
Fig. 5: Seasonality, diet composition and carbon flows.

Data availability

The contemporary hunter-gatherer data and environmental variables used in the analysis are available in the Supplementary Data.

Code availability

Source code (in Python) of the FORGE model and its output files (in NetCDF format) for this study, including the three sets of global simulations (S0, S1, S2), are provided in Supplementary Software. The corresponding input files for the FORGE model are available at https://doi.org/10.6084/m9.figshare.14995320.v2.

References

  1. Binford, L. R. Constructing Frames of Reference: An Analytical Method for Archaeological Theory Building Using Hunter-Gatherer and Environmental Data Sets (Univ. of California Press, 2001).

  2. Kelly, R. L. The Lifeways of Hunter-Gatherers: The Foraging Spectrum (Cambridge Univ. Press, 2013).

  3. Tallavaara, M., Eronen, J. T. & Luoto, M. Productivity, biodiversity, and pathogens influence the global hunter-gatherer population density. Proc. Natl Acad. Sci. USA 115, 1232–1237 (2018).

    Article  CAS  PubMed  Google Scholar 

  4. Eriksson, A. et al. Late Pleistocene climate change and the global expansion of anatomically modern humans. Proc. Natl Acad. Sci. USA 109, 16089–16094 (2012).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  5. Gurven, M. D. & Davison, R. J. Periodic catastrophes over human evolutionary history are necessary to explain the forager population paradox. Proc. Natl Acad. Sci. USA https://doi.org/10.1073/pnas.1902406116 (2019).

  6. Tallavaara, M., Luoto, M., Korhonen, N., Järvinen, H. & Seppä, H. Human population dynamics in Europe over the Last Glacial Maximum. Proc. Natl Acad. Sci. USA 112, 8232–8237 (2015).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  7. Bradshaw, C. J. A. et al. Minimum founding populations for the first peopling of Sahul. Nat. Ecol. Evol. 3, 1057–1063 (2019).

    Article  PubMed  Google Scholar 

  8. Kavanagh, P. H. et al. Hindcasting global population densities reveals forces enabling the origin of agriculture. Nat. Hum. Behav. 2, 478–484 (2018).

    Article  PubMed  Google Scholar 

  9. Porter, C. C. & Marlowe, F. W. How marginal are forager habitats? J. Archaeol. Sci. 34, 59–68 (2007).

    Article  Google Scholar 

  10. Reyes-García, V. & Pyhälä, A. Hunter-Gatherers in a Changing World (Springer International Publishing, 2017).

  11. Lee, R. B. & Daly, R. The Cambridge Encyclopedia of Hunters and Gatherers (Cambridge Univ. Press, 1999).

  12. Kitanishi, K. Seasonal changes in the subsistence activities and food intake of the Aka hunter-gatherers in northeastern Congo. Afr. Study Monogr. 16, 73–118 (1995).

    Google Scholar 

  13. Timmermann, A. & Friedrich, T. Late Pleistocene climate drivers of early human migration. Nature 538, 92–95 (2016).

    Article  CAS  PubMed  Google Scholar 

  14. Keeley, L. H. Hunter-gatherer economic complexity and ‘population pressure’: a cross-cultural analysis. J. Anthropol. Archaeol. 7, 373–411 (1988).

  15. Fisher, J. B., Huntzinger, D. N., Schwalm, C. R. & Sitch, S. Modeling the terrestrial biosphere. Annu. Rev. Environ. Resour. 39, 91–123 (2014).

    Article  Google Scholar 

  16. Pachzelt, A., Forrest, M., Rammig, A., Higgins, S. I. & Hickler, T. Potential impact of large ungulate grazers on African vegetation, carbon storage and fire regimes. Glob. Ecol. Biogeogr. 24, 991–1002 (2015).

    Article  Google Scholar 

  17. Zhu, D. et al. The large mean body size of mammalian herbivores explains the productivity paradox during the Last Glacial Maximum. Nat. Ecol. Evol. 2, 640–649 (2018).

    Article  PubMed  PubMed Central  Google Scholar 

  18. Dyble, M., Thorley, J., Page, A. E., Smith, D. & Migliano, A. B. Engagement in agricultural work is associated with reduced leisure time among Agta hunter-gatherers. Nat. Hum. Behav. 3, 792–796 (2019).

  19. Hill, K., Kaplan, H., Hawkes, K. & Hurtado, A. M. Men’s time allocation to subsistence work among the Ache of eastern Paraguay. Hum. Ecol. 13, 29–47 (1985).

    Article  Google Scholar 

  20. Hill, K., Hawkes, K., Hurtado, M. & Kaplan, H. Seasonal variance in the diet of Ache hunter-gatherers in eastern Paraguay. Hum. Ecol. 12, 101–135 (1984).

    Article  CAS  Google Scholar 

  21. Marlowe, F. W. et al. Honey, Hadza, hunter-gatherers, and human evolution. J. Hum. Evol. 71, 119–128 (2014).

    Article  PubMed  Google Scholar 

  22. Cordain, L. et al. Plant–animal subsistence ratios and macronutrient energy estimations in worldwide hunter-gatherer diets. Am. J. Clin. Nutr. 71, 682–692 (2000).

    Article  CAS  PubMed  Google Scholar 

  23. Gurven, M. & Kaplan, H. Longevity among hunter-gatherers: a cross-cultural examination. Popul. Dev. Rev. 33, 321–365 (2007).

    Article  Google Scholar 

  24. Klein Goldewijk, K., Beusen, A. & Janssen, P. Long-term dynamic modeling of global population and built-up area in a spatially explicit way: HYDE 3.1. Holocene 20, 565–573 (2010).

    Article  Google Scholar 

  25. Marlowe, F. W. Hunter-gatherers and human evolution. Evol. Anthropol. 14, 54–67 (2005).

    Article  Google Scholar 

  26. Burger, J. R. & Fristoe, T. S. Hunter-gatherer populations inform modern ecology. Proc. Natl Acad. Sci. USA 115, 1137–1139 (2018).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  27. Hurtado, A. M. & Hill, K. R. Seasonality in a foraging society: variation in diet, work effort, fertility, and sexual division of labor among the Hiwi of Venezuela. J. Anthropol. Res. 46, 293–346 (1990).

    Article  Google Scholar 

  28. Wilmsen, E. N. Studies in diet, nutrition, and fertility among a group of Kalahari Bushmen in Botswana. Soc. Sci. Inf. 21, 95–125 (1982).

    Article  Google Scholar 

  29. Lee, R. B. in Man the Hunter (eds. Lee, R. B. & DeVore, I.) 30–48 (Aldine de Gruyter, 1968).

  30. Hamilton, M. J., Milne, B. T., Walker, R. S. & Brown, J. H. Nonlinear scaling of space use in human hunter-gatherers. Proc. Natl Acad. Sci. USA 104, 4765–4769 (2007).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  31. Messer, E. Anthropological perspectives on diet. Annu. Rev. Anthropol. 13, 205–249 (1984).

    Article  Google Scholar 

  32. Testart, A. et al. The significance of food storage among hunter-gatherers: residence patterns, population densities, and social Inequalities [and Comments and Reply]. Curr. Anthropol. 23, 523–537 (1982).

    Article  Google Scholar 

  33. Winterhalder, B. Diet choice, risk, and food sharing in a stochastic environment. J. Anthropol. Archaeol. 5, 369–392 (1986).

    Article  Google Scholar 

  34. Kelly, R. L., Pelton, S. R. & Robinson, E. in Towards a Broader View of Hunter-Gatherer Sharing (eds Lavi, N. & Friesem, D. E.) Ch. 10 (McDonald Institute for Archaeological Research, 2019).

  35. Joannes-Boyau, R. et al. Elemental signatures of Australopithecus africanus teeth reveal seasonal dietary stress. Nature 572, 112–115 (2019).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  36. Smits, S. A. et al. Seasonal cycling in the gut microbiome of the Hadza hunter-gatherers of Tanzania. Science 357, 802–806 (2017).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  37. Barnosky, A. D. Assessing the causes of Late Pleistocene extinctions on the continents. Science 306, 70–75 (2004).

    Article  CAS  PubMed  Google Scholar 

  38. Henrich, J. Demography and cultural evolution: how adaptive cultural processes can produce maladaptive losses—the Tasmanian case. Am. Antiq. 69, 197–214 (2004).

    Article  Google Scholar 

  39. Powell, A., Shennan, S. & Thomas, M. G. Late Pleistocene demography and the appearance of modern human behavior. Science 324, 1298–1301 (2009).

    Article  CAS  PubMed  Google Scholar 

  40. D’Alpoim Guedes, J. A., Crabtree, S. A., Bocinsky, R. K. & Kohler, T. A. Twenty-first century approaches to ancient problems: climate and society. Proc. Natl Acad. Sci. USA 113, 14483–14491 (2016).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  41. Cegielski, W. H. & Rogers, J. D. Rethinking the role of Agent-based modeling in archaeology. J. Anthropol. Archaeol. 41, 283–298 (2016).

    Article  Google Scholar 

  42. Axtell, R. L. et al. Population growth and collapse in a multiagent model of the Kayenta Anasazi in long house valley. Proc. Natl Acad. Sci. USA 99, 7275–7279 (2002).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  43. Hayden, B. Research and development in the stone age: technological transitions among hunter-gatherers. Curr. Anthropol. 22, 519–548 (1981).

    Article  Google Scholar 

  44. Itkonen, T. I. Suomen Lappalaiset Vuoteen 1945. Ensimmäinen Osa (WSOY, 1848).

  45. Kirby, K. R. et al. D-PLACE: a global database of cultural, linguistic and environmental diversity. PLoS ONE 11, e0158391 (2016).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  46. MODIS NPP (MOD17A3) (NTSG, accessed 12 March 2015); http://files.ntsg.umt.edu/data/NTSG_Products/MOD17/

  47. Defries, R.S. et al. ISLSCP II Continuous Fields of Vegetation Cover, 1992–1993 (ORNL DAAC, 2009); https://doi.org/10.3334/ORNLDAAC/931

  48. Bodesheim, P., Jung, M., Gans, F., Mahecha, M. D. & Reichstein, M. Upscaled diurnal cycles of land–atmosphere fluxes: a new global half-hourly data product. Earth Syst. Sci. Data 10, 1327–1365 (2018).

    Article  Google Scholar 

  49. Šímová, I. & Storch, D. The enigma of terrestrial primary productivity: measurements, models, scales and the diversity–productivity relationship. Ecography 40, 239–252 (2017).

    Article  Google Scholar 

  50. Bontemps, S. et al. Consistent global land cover maps for climate modelling communities: current achievements of The ESA Land Cover CCI. In Proc. ESA Living Planet Symposium 2013 (ESA, 2013).

  51. Bliege Bird, R. & Bird, D. W. Why women hunt—risk and contemporary foraging in a western desert aboriginal community. Curr. Anthropol. 49, 655–693 (2008).

    Article  Google Scholar 

  52. Bliege Bird, R., Codding, B. F. & Bird, D. W. What explains differences in men’s and women’s production? Hum. Nat. 20, 105–129 (2009).

    Article  PubMed  Google Scholar 

  53. Reyes-García, V., Díaz-Reviriego, I., Duda, R., Fernández-Llamazares, Á. & Gallois, S. ‘Hunting otherwise’—women’s hunting in two contemporary forager-horticulturalist societies. Hum. Nat. 31, 203–221 (2020).

    Article  PubMed  Google Scholar 

  54. Krinner, G. et al. A dynamic global vegetation model for studies of the coupled atmosphere-biosphere system. Global Biogeochem. Cycles 19, GB1015 (2005).

  55. Hamilton, M. J., Lobo, J., Rupley, E., Youn, H. & West, G. B. The ecological and evolutionary energetics of hunter‐gatherer residential mobility. Evol. Anthropol. 25, 124–132 (2016).

    Article  PubMed  PubMed Central  Google Scholar 

  56. Abrams, P. A. & Ginzburg, L. R. The nature of predation: prey dependent, ratio dependent or neither? Trends Ecol. Evol. 15, 337–341 (2000).

    Article  CAS  PubMed  Google Scholar 

  57. Winterhalder, B., Baillargeon, W., Cappelletto, F., Randolph Daniel, I. & Prescott, C. The population ecology of hunter-gatherers and their prey. J. Anthropol. Archaeol. 7, 289–328 (1988).

    Article  Google Scholar 

  58. Illius, A. W. & O’Connor, T. G. Resource heterogeneity and ungulate population dynamics. Oikos 89, 283–294 (2000).

    Article  Google Scholar 

  59. Golley, F. B. Energy values of ecological materials. Ecology 42, 581–584 (1961).

    Article  Google Scholar 

  60. Herbers, J. M. Time resources and laziness in animals. Oecologia 49, 252–262 (1981).

    Article  PubMed  Google Scholar 

  61. Raichlen, D. A. et al. Sitting, squatting, and the evolutionary biology of human inactivity. Proc. Natl Acad. Sci. USA https://doi.org/10.1073/pnas.1911868117 (2020).

  62. Abrams, H., Jr. in Food and Evolution (eds Harris, M. & Ross, E.) 207–223 (Temple Univ. Press, 1987).

  63. Hanya, G. & Aiba, S. Fruit fall in tropical and temperate forests: implications for frugivore diversity. Ecol. Res. 25, 1081–1090 (2010).

    Article  Google Scholar 

  64. Gherardi, L. A. & Sala, O. E. Global patterns and climatic controls of belowground net carbon fixation. Proc. Natl Acad. Sci. USA https://doi.org/10.1073/pnas.2006715117 (2020).

  65. van Zonneveld, M. et al. Human diets drive range expansion of megafauna-dispersed fruit species. Proc. Natl Acad. Sci. USA 115, 3326–3331 (2018).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  66. Max R., Hannah R. & Esteban Ortiz-Ospina World Population Growth (GCDL, 2020); https://ourworldindata.org/world-population-growth

  67. Pontzer, H. et al. Metabolic acceleration and the evolution of human brain size and life history. Nature 533, 390 (2016).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  68. Viovy, N. CRUNCEP Version 7—Atmospheric Forcing Data for the Community Land Model (Research Data Archive at the National Center for Atmospheric Research, Computational and Information Systems Laboratory, 2018); https://doi.org/10.5065/PZ8F-F017

  69. Sobol, I. Global sensitivity indices for nonlinear mathematical models and their Monte Carlo estimates. Math. Comput. Simul. 55, 271–280 (2001).

    Article  Google Scholar 

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Acknowledgements

D.Z. and E.D.G. acknowledge the financial support from the European Research Council under the European Union’s Horizon 2020 Research and Innovation Programme (agreement no. 682602, to E.D.G.). D.Z. also acknowledges support from the National Natural Science Foundation of China (grant no. 41988101). V.R.-G. acknowledges support from the European Research Council under agreement no. 771056.

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D.Z. and E.D.G. conceived the study and model design. D.Z. built the model, performed the analyses and wrote the first draft. E.D.G. provided discussion and suggestions throughout the process. V.R.-G. and P.C. contributed to the interpretation of the results and writing of the manuscript.

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Correspondence to Dan Zhu.

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The authors declare no competing interests.

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Peer review information Nature Ecology & Evolution thanks Trevor Fristoe and the other, anonymous, reviewer(s) for their contribution to the peer review of this work. Peer reviewer reports are available.

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Supplementary information

Supplementary Information

Supplementary Figs. 1–23, Discussion 1–3 and Tables 1–4.

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Supplementary Data

The contemporary hunter-gatherer data and environmental variables used in the analysis.

Supplementary Software

Source code (in Python) of the FORGE model and its output files (in NetCDF format) including the three sets of global simulations (S0, S1, S2).

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Zhu, D., Galbraith, E.D., Reyes-García, V. et al. Global hunter-gatherer population densities constrained by influence of seasonality on diet composition. Nat Ecol Evol 5, 1536–1545 (2021). https://doi.org/10.1038/s41559-021-01548-3

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