Population dynamics and competitive outcome derive from resource allocation statistics: The governing influence of the distinguishability of individuals

• Species dynamics derive from maximizing the Boltzmann entropy of resource allocation.
• Competition outcome depends on the relative individual distinguishability DrDr.
• A smaller DrDr leads to a stronger stabilizing mechanism in support of coexistence.
• Species abundance distribution and the energetic equivalence rule naturally emerge.

Model predictions for species competition outcomes highly depend on the assumed form of the population growth function. In this paper we apply an alternative inferential method based on statistical mechanics, maximizing Boltzmann entropy, to predict resource-constrained population dynamics and coexistence. Within this framework, population dynamics and competition outcome can be determined without assuming any particular form of the population growth function. The dynamics of each species is determined by two parameters: the mean resource requirement θθ (related to the mean metabolic rate) and individual distinguishability DrDr (related to intra- compared to interspecific functional variation). Our theory clarifies the condition for the energetic equivalence rule (EER) to hold, and provide a statistical explanation for the importance of species functional variation in determining population dynamics and coexistence patterns.