Evol Ecol Res 19: 85-102 (2018)     Full PDF if your library subscribes.

A stochastic density-dependent model of long-term population dynamics in hunter-gatherer populations

Marcus J. Hamilton1,2 and Robert S. Walker1

1Department of Anthropology, University of Missouri, Columbia, Missouri, USA and 2Santa Fe Institute, Santa Fe, New Mexico, USA

Correspondence: M.J. Hamilton, Department of Anthropology, University of Missouri, Columbia, MO 65211, USA. email: hamiltonmj@missouri.edu


Background: All biological populations exhibit fluctuations in size over time due to stochastic variation in growth rates that result in local extinctions, but these dynamics are poorly understood in traditional human populations. Here, we explore extinction processes over human evolutionary history due to the effects of (i) demographic stochasticity, (ii) environmental stochasticity, and (iii) periodic catastrophes.

Organism: Modern humans, Homo sapiens.

Methods: We built a mathematical model of stochastic population dynamics, estimated its parameters using ethnographic data, and simulated probability distributions of extinction outcomes using Monte Carlo methods.

Results: Although expected times to extinction vary under different conditions, hunter-gatherer populations likely experienced local extinction events every few hundred years (or every few generations).

Conclusions: Played out over the evolutionary time scale of the human species (∼250,000 years), stochastic variation in growth rates resulted in a near-constant turnover of local populations, contributing to the near-zero growth of human populations over much of our evolutionary history.

Keywords: fission-fusion, forager societies, metapopulation, population growth, stochastic processes.

IF you are connected using the IP of a subscribing institution (library, laboratory, etc.)
or through its VPN.


        © 2018 Marcus J. Hamilton. All EER articles are copyrighted by their authors. All authors endorse, permit and license Evolutionary Ecology Ltd. to grant its subscribing institutions/libraries the copying privileges specified below without additional consideration or payment to them or to Evolutionary Ecology, Ltd. These endorsements, in writing, are on file in the office of Evolutionary Ecology, Ltd. Consult authors for permission to use any portion of their work in derivative works, compilations or to distribute their work in any commercial manner.

       Subscribing institutions/libraries may grant individuals the privilege of making a single copy of an EER article for non-commercial educational or non-commercial research purposes. Subscribing institutions/libraries may also use articles for non-commercial educational purposes by making any number of copies for course packs or course reserve collections. Subscribing institutions/libraries may also loan single copies of articles to non-commercial libraries for educational purposes.

       All copies of abstracts and articles must preserve their copyright notice without modification.