Quasi-Equilibrium States and Phase Transitions in Biological Evolution

Entropy (Basel). 2024 Feb 27;26(3):201. doi: 10.3390/e26030201.

Abstract

We developed a macroscopic description of the evolutionary dynamics by following the temporal dynamics of the total Shannon entropy of sequences, denoted by S, and the average Hamming distance between them, denoted by H. We argue that a biological system can persist in the so-called quasi-equilibrium state for an extended period, characterized by strong correlations between S and H, before undergoing a phase transition to another quasi-equilibrium state. To demonstrate the results, we conducted a statistical analysis of SARS-CoV-2 data from the United Kingdom during the period between March 2020 and December 2023. From a purely theoretical perspective, this allowed us to systematically study various types of phase transitions described by a discontinuous change in the thermodynamic parameters. From a more-practical point of view, the analysis can be used, for example, as an early warning system for pandemics.

Keywords: Hamming distance; Shannon entropy; biological evolution; multilevel learning; phase transitions; quasi-equilibrium states; statistical ensembles; thermodynamics.

Grants and funding

This research received no external funding.