Interspecific allometric scaling of unicellular organisms as an evolutionary process of food chain creation

Abstract: Metabolism of living organisms is a foundation of life. The metabolic rate (energy production per unit time) increases slower than organisms' mass. When this phenomenon is considered across different species, it is called interspecific allometric scaling, whose causes are unknown. We argue that the cause of interspecific allometric scaling is the total effect of physiological and adaptation mechanisms inherent to organisms composing a food chain. Together, the workings of these mechanisms are united by a primary goal of any living creature - its successful reproduction. This primary necessity of each organism and of the entire food chain is that common denominator, to which all organisms adjust their metabolic rates. In this article, we consider unicellular organisms, while the second paper studies multicellular organisms and the entire concept in more detail. Here, using the proposed concepts and experimentally verified growth models of five different unicellular organisms, we obtain close to experimental findings values of allometric exponents of 0.757 for the end of growth and 0.853 for the beginning of growth. These results comply with experimental observations and prove our theory that the requirement of successful reproduction within the food chain is an important factor shaping interspecific allometric scaling.