Banavar Jayanth R, Damuth John, Maritan Amos, Rinaldo Andrea
Department of Physics, 104 Davey Laboratory, Pennsylvania State University, University Park, PA 16802, USA.
Proc Natl Acad Sci U S A. 2002 Aug 6;99(16):10506-9. doi: 10.1073/pnas.162216899. Epub 2002 Jul 29.
It is widely accepted that metabolic rates scale across species approximately as the 3/4 power of mass in most if not all groups of organisms. Metabolic demand per unit mass thus decreases as body mass increases. Metabolic rates reflect both the ability of the organism's transport system to deliver metabolites to the tissues and the rate at which the tissues use them. We show that the ubiquitous 3/4 power law for interspecific metabolic scaling arises from simple, general geometric properties of transportation networks constrained to function in biological organisms. The 3/4 exponent and other observed scaling relationships follow when mass-specific metabolic demands match the changing delivery capacities of the network at different body sizes. Deviation from the 3/4 exponent suggests either inefficiency or compensating physiological mechanisms. Our conclusions are based on general arguments incorporating the minimum of biological detail and should therefore apply to the widest range of organisms.
人们普遍认为，在大多数（如果不是所有）生物群体中，代谢率随物种的体重变化大致呈体重的3/4次幂关系。因此，单位质量的代谢需求随着体重的增加而降低。代谢率既反映了生物体运输系统向组织输送代谢物的能力，也反映了组织利用这些代谢物的速率。我们表明，种间代谢标度的普遍3/4幂律源于受限于在生物体内发挥作用的运输网络的简单、一般几何特性。当特定质量的代谢需求与不同体型下网络不断变化的输送能力相匹配时，就会出现3/4指数和其他观察到的标度关系。偏离3/4指数表明效率低下或存在补偿性生理机制。我们的结论基于包含最少生物学细节的一般论点，因此应适用于最广泛的生物体。
