Browsing by Author "Freeman, Jacob"

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    Landscape Engineering Impacts the Long-Term Stability of Agricultural Populations
    (2021) Freeman, Jacob; Anderies, John M.; Beckman, Noelle G.; Robinson, Erick; Baggio, Jacopo A.; Bird, Darcy; Nicholson, Christopher; Finley, Judson Byrd; Capriles, Jose M.; Gil, Adolfo F.; Byers, David; Gayo, Eugenia; Latorre, Claudio
    Explaining the stability of human populations provides knowledge for understanding the resilience of human societies to environmental change. Here, we use archaeological radiocarbon records to evaluate a hypothesis drawn from resilience thinking that may explain the stability of human populations: Faced with long-term increases in population density, greater variability in the production of food leads to less stable populations, while lower variability leads to more stable populations. However, increased population stability may come with the cost of larger collapses in response to rare, large-scale environmental perturbations. Our results partially support this hypothesis. Agricultural societies that relied on extensive landscape engineering to intensify production and tightly control variability in the production of food experienced the most stability. Contrary to the hypothesis, these societies also experienced the least severe population declines. We propose that the interrelationship between landscape engineering and increased political-economic complexity reduces the magnitude of population collapses in a region.
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    Positive feedbacks in deep-time transitions of human populations
    (2024) Lima, Mauricio; Gayo, Eugenia M.; Estay, Sergio A.; Gurruchaga, Andone; Robinson, Erick; Freeman, Jacob; Latorre, Claudio; Bird, Darcy
    Abrupt and rapid changes in human societies are among the most exciting population phenomena. Human populations tend to show rapid expansions from low to high population density along with increased social complexity in just a few generations. Such demographic transitions appear as a remarkable feature of Homo sapiens population dynamics, most likely fuelled by the ability to accumulate cultural/technological innovations that actively modify their environment. We are especially interested in establishing if the demographic transitions of pre-historic populations show the same dynamic signature of the Industrial Revolution transition (a positive relationship between population growth rates and size). Our results show that population growth patterns across different pre-historic societies were similar to those observed during the Industrial Revolution in developed western societies. These features, which appear to have been operating during most of our recent demographic history from hunter-gatherers to modern industrial societies, imply that the dynamics of cooperation underlay sudden population transitions in human societies.This article is part of the theme issue 'Evolution and sustainability: gathering the strands for an Anthropocene synthesis'.