Tuesday, August 4, 2009 - 1:45 PM

SYMP 8-2: Scaling energy use in human systems from hunter-gatherers to nation states

Marcus J. Hamilton, University of New Mexico


Like all biological species, humans harvest resources from the environment to meet energy requirements. The metabolic rate not only sets resource demands but is also a major determinant of ecological relations at multiple levels of biological organization. In mammals, including humans, scaling relations between population size and home range describe the complex interactions between individual space use, population structure, and energy demand. Here, we use metabolic scaling theory to derive hypotheses of energy use in human systems, and test these predictions using a wide diversity of data sets from across the spectrum of human socio-economies, from recent hunter-gatherers to 21st century nation states


First we show that the home ranges of hunter-gatherer populations scale allometrically as the 3/4-power of their population sizes rather than isometrically as might be expected on the basis of individual resource demands. Using network theory, we also show that hunter-gatherer social networks are structurally self-similar. We then show that these scaling relations are quantitatively similar across the entire spectrum of human socio-economies and discuss the implications. Our results suggest that the same set of fundamental physical and biological processes that lead to the formation of self-similar fractal-like distribution networks in many complex systems in Nature lead to similar complex structures in human social systems.