Adaptive Responses to Demographic Fragility: Mitigating Stochastic Effects in Early Island Colonization

• Published in: Human ecology : an interdisciplinary journal Vol. 43; no. 5; pp. 721 - 734
• Main Author: Leppard, Thomas P.
• Format: Journal Article
• Language: English
• Published: New York Springer 01.10.2015; Springer US; Springer Nature B.V
• Subjects: Anthropology; Archaeology; Colonization; Cultural differences; Demographics; Ecology; Environmental Management; Extinction; Extinction behavior; Fitness; Fragility; Genetics; Geography; Islands; Isolation; Network analysis; Population; Populations; Prehistoric era; RESEARCH REPORTS; Responses; Social factors; Social Sciences; Sociology; Spatial discrimination; Stochastic processes; Stochasticity; Island archaeology; Insularity; Population ecology; Social evolution; Palaeodemography; Prehistoric colonization
• ISSN: 0300-7839; 1572-9915
• DOI: 10.1007/s10745-015-9779-4

This paper advances the debate regarding the social relations of prehistoric islanders beyond the dichotomy of isolation vs connectivity by proposing a general and cross-cultural model of adaptive behavioral responses to stochastically-forced demographic fragility. I show that smaller populations—more likely earlier in the settlement histories of islands—are more exposed to localized extinction via stochastic processes. To alleviate this greater degree of exposure, maintaining social links that allow for genetic flow between otherwise isolated populations should increase overall fitness. Conversely, as discrete populations expand, the imperative for access to a widely distributed metapopulation, and hence the need to maintain these links, should decrease. This is illustrated via simple network analysis. Potential venues for testing this general model are outlined; wider implications for the archaeology of colonization, and for spatial modeling of social interaction, are briefly discussed.