On the natural selection of body mass allometries

I use data based life history models to illustrate natural selection causes for the evolution of inter-specific body mass allometries in birds and mammals. This illustrates i) how the primary selection of resource handling and mass-specific metabolism generates net energy for individuals, ii) how the selected net energy generates a population dynamic feedback selection where intra-specific interactive competition selects body masses that scale in proportion with net energy on the timescale of natural selection, iii) how the feedback selection of body mass buffers ecological variation in survival, iv) how the exponents of body mass allometries are selected from the dominant spatial dimensionality of the foraging ecology, v) how the population density allometry is affected by inter-specific competition, and vi) how primary selected metabolism bends the metabolic allometry and explains a metabolic invariance across major taxa of vertebrates.