¹N.N. Semenov Federal Research Center for Chemical Physics of the Russian Academy of Sciences, Moscow, Russia
²Russian Peoples' Friendship University n.a. Patrice Lumumba, Moscow, Russia
³N.V. Sklifosovsky Research Institute of Emergency Medicine, Moscow, Russia
⁴Russian University of Biotechnology (ROSBIOTECH), Moscow, Russia

Abstract. The theory of numerical growth of living organisms in nature is proposed, in which "active components" transform "neutral components" into new "active centers" as a result of branched, chain processes, according to the autocatalytic equation, and their numerical growth is described by logistic functions. These components and the conditions of their interaction form an "autocatalytic set" that is universal for many processes of numerical growth of various living organisms in nature. Our theory follows from the "theory of chain reactions" and the "mathematical theory of epidemics and pandemics based on the laws of chain and thermal explosions" and can be used to describe the spread of infections among animals and will be useful for describing many processes of growth of wildlife. The theory is likely to make it possible to study many processes of the spread of various "viral ideas" among people, which may be of considerable practical interest in the analysis of social phenomena.

Key words: theory of chain reactions, chain processes, logistic function