Energetic Macroevolution of Vertebrates

Abstract

An analysis of our own data and published data on comparable standard metabolism in vertebrates has been carried out. It was shown that within each family and most of the orders this parameter varies insignificantly and the mean values for the comparable standard metabolism are grouped around certain values presumably corresponding to the stationary states to which organisms aspire in the course of evolution. There was a significant difference in the comparable standard metabolism in poikilothermic and homeothermic animals, apparently related to the existence of a heat barrier, which is overcome by the appearance of thermoregulation. In total, seven levels of stationary states were distinguished for vertebrates and 12 of them for all animals. It was established that the ratio of the values of the comparable standard metabolism for neighboring levels varies insignificantly and is ~2.2. It was noted that in the process of macroevolution of phyla and classes, their constituent units occupy ever higher stationary levels. A possible mechanism of transition from one stationary level to another is discussed.