ENERGETICS OF SOCIAL PHENOMENA - PHYSICS APPLIED TO EVOLUTIONARY BIOLOGY

The potential usefulness of applications of two physical concepts to e volutionary biology was evaluated on ant societies. The optimization p rinciple, which predicts a more efficient use of energy by more sophis ticated societies, was contrasted to that of irreversible thermodynami cs, predicting an increase in orderliness and thus an increase in ener gy consumption per unit of biomass. Our results on oxygen consumption measurements of ant colonies showed a complex and non-linear relations hip between colony size and energy consumption per unit mass, that can be explained by irreversible thermodynamics and catastrophe theory, w hereas an additional exponential inverse relationship may be explained by optimization principles. Thus, social complexity is related to ene rgy consumption in a discontinuous manner, and seems to be bound by bo th negentropy content of a society and social-optimization mechanisms.