[Population waves as a condition for increasing ecological stability of organisms in the process of vertical evolution].

Ecological stability of an organism, which determines the possibility of its existence under changing environmental conditions, can be estimated as the probability of the participation of each viable offspring in reproduction. In developing species, the periodic rises and falls in the population size (Chetverikov's "waves of life") can lead to changes in ecological stability, which is of macroevolutionary importance. Under conditions of isolation such changes generally result in specialization of intraspecific races but they could then lead to an increase in ecological stability of hybrid forms. Ecological stability of prosperous species increases during macroevolution due to combinative recombination between specialized intraspecific races or closely related species.