SCALING OF BASAL AND MAXIMUM METABOLIC-RATE IN RODENTS AND THE AEROBIC CAPACITY MODEL FOR THE EVOLUTION OF ENDOTHERMY

The assumption of correlation between basal metabolic rate (BMR) and maximum metabolic rate (MMR) was tested in 29 species and in 42 groups of individuals from allopatric populations and individuals during different seasons using the same method. That is, I only used original data and information derived from the literature where both MMR and BMR were studied in the same individuals, and maximum resting metabolic rate of thermoregulation was only measured by the He-O2 method. Both total MMR and BMR (mL O2/h) increased allometrically with body mass (m(b) in g). Statistical analysis (ANCOVA) indicated insignificant differences between slopes, but significant differences between intercepts in both analyses (species and groups). Partial correlation analysis revealed a significant positive correlation between MMR and BMR after the effect of m(b) was removed. In contrast with previous suggestions, results from my study supported the general rule of correlation between MMR and BMR and the aerobic capacity model for the evolution of endothermy.