[Evolutionary bioenergetic trap and progressive evolution of animals]

We propose a macroscopic pathway to increase energy metabolism during progressive evolution with reducing size of animal body. If standard metabolism significantly increases in the course of body size reduction through increased coefficient b from the allometric equation (1), two cases are possible: coefficient b remains constant (1) or returns to the normal value (2) at increasing body weight in a given animal group. In the first case, an animal group appears in an evolutionary trap considering possible increase in body size, since the standard metabolism at increasing weight becomes lower starting from a certain point as compared to other animals of the same type. In the second case, increasing body size elevates standard metabolism relative to other animals of the same type, which offers an evolutionary advantage to this group.