Affiliation:
1. Saint Petersburg Electrotechnical University “LETI”, Saint Petersburg 197022, Russia
2. Institute for Problems in Mechanical Engineering of the Russian Academy of Sciences, Saint Petersburg 199178, Russia
Abstract
This paper aims to explain the transition to multicellularity as a consequence of the evolutionary response to stress. The proposed model is composed of three parts. The first part details stochastic biochemical kinetics within a reactor (potentially compartmentalized), where kinetic rates are influenced by random stress parameters, such as temperature, toxins, oxidants, etc. The second part of the model is a feedback mechanism governed by a genetic regulation network (GRN). The third component involves stochastic dynamics that describe the evolution of this network. We assume that the organism remains viable as long as the concentrations of certain key reagents are maintained within a defined range (the homeostasis domain). For this model, we calculate the probability estimate that the system will stay within the homeostasis domain under stress impacts. Under certain assumptions, we show that a GRN expansion increases the viability probability in a very sharp manner. It is shown that multicellular organisms increase their viability due to compartment organization and stem cell activity. By the viability probability estimates, an explanation of the Peto paradox is proposed: why large organisms are stable with respect to cancer attacks.
Funder
Ministry of Science and Higher Education of the Russian Federation
Subject
General Mathematics,Engineering (miscellaneous),Computer Science (miscellaneous)
Reference62 articles.
1. Koonin, E.V. (2011). The Logic of Chance: The Nature and Origin of Biological Evolution, FT Press.
2. Virus-host arms race at the joint origin of multicellularity and programmed cell death;Iranzo;Cell Cycle,2014
3. Viruses and mobile elements as drivers of evolutionary transitions;Koonin;Phil. Trans. R. Soc. B,2016
4. Maynard Smith, J., and Schatzmary, E. (1995). The Major Transitions in Evolution, Oxford University Press.
5. Fisher, R.A. (1930). The Genetical Theory of Natural Selection, Clarendon Press.