Fig. 4. Relationship between basal metabolic rate (BMR, ml O₂ h^-1) and body mass (M_b, g). BMR=3.98M_b^{0.686±0.014 (95% CI)}, r²=0.94, N=571. Data were selected according to McNab (1997) and taken from White and Seymour (2003). Lineages for which basal conditions were unlikely to be achieved (large herbivores, Macropodidae, Lagomorpha, and Soricidae) were excluded for reasons discussed in the text.