[Energy metabolism and the direction of evolutionary progress in the class of mammals].

The data on dependence of standard metabolism on body weight in 518 mammalian species have been summarized. Standard metabolism differs in representatives of different classes and families. The higher it is, the more complicated is the organization of the animals. Comparison of standard metabolism in different classes of mammals with the time of their paleontological origin demonstrates that evolutionary process in mammals was directed towards the increase in energetic metabolism of animals.