The predominance of quarter‐power scaling in biology

1 Recent studies have resurrected the debate over the value for the allometric scaling exponent that relates whole-organism metabolic rate to body size. Is it 3/4 or 2/3? This question has been raised before and resolved in favour of 3/4. Like previous ones, recent claims for a value of 2/3 are based almost entirely on basal metabolic rate (BMR) in mammals. 2 Here we compile and analyse a new, larger data set for mammalian BMR. We show that interspecific variation in BMR, as well as field metabolic rates of mammals, and basal or standard metabolic rates for many other organisms, including vertebrates, invertebrates, protists and plants, all scale with exponents whose confidence intervals include 3/4 and…