Energy flow and the persistence of a human population: a simulation analysis

The authors describe "a human ecosystem model, NUNOA, [which] simulates the yearly energy balance of individuals, families, and extended families in a hypothetical farming and herding community of Quechua Indians in the high Andes. The yearly energy demand of each family, based on the caloric requirements of its members, is computed by simulation of agricultural and herding activities in response to stochastic environmental conditions. The family energy balance is used in determining births, deaths, marriages, and resource sharing." The model can be used "to investigate the effect of changes in marriage patterns, resource sharing patterns, or subsistence activities on the ability of the human population to survive in the harsh Andean environment. Results from the model suggest that the substructuring of a population into extended families provides a mechanism for sheltering the population from control by exogenous influences. A population without substructures for resource sharing is shown to be unstable in such an unpredictable environment."