Power laws in biology

Why live larger mammals longer than smaller ones? Why is the energy consumption per body mass of a mouse six times higher than that of a human? These questions and many others dealing with biological allometry kept and keep biologists busy since the second half of nineteenth century and as it seems, the ultimate answers have not yet been given. Analyzing allometry is particularly attractive since the biomass of organisms varies over more than twenty orders of magnitude from approximately 1 pg = 10 g (mycoplasma, a very small bacterium) to 2  10 g (blue whale), and in case of mammals the lower limit by mass is provided by the Etruscan Shrew with about 1 g thus still leaving eight orders of magnitude variation in body mass. The wide range of animal sizes makes body mass related properties an ideal test ground for scaling relations, in particular for power laws, and this is the reason why body mass allometry is chosen here as a representative and data rich example for other power laws. The number of papers dealing with attempt to scale body mass dependent relations in log/log-plots is indeed enormous.