Darwinian evolution as a dynamical principle

Proc Natl Acad Sci U S A. 2023 Mar 14;120(11):e2218390120. doi: 10.1073/pnas.2218390120. Epub 2023 Mar 7.

Abstract

Darwinian evolution (DE)-biology's powerful process of adaptation-is remarkably different from other known dynamical processes. It is antithermodynamic, driving away from equilibrium; it has persisted for 3.5 billion years; and its target, fitness, can seem like "Just So" stories. For insights, we make a computational model. In the Darwinian Evolution Machine (DEM) model, resource-driven duplication and competition operate inside a cycle of search/compete/choose. We find the following: 1) DE requires multiorganism coexistence for its long-term persistence and ability to cross fitness valleys. 2) DE is driven by resource dynamics, like booms and busts, not just by mutational change. And, 3) fitness ratcheting requires a mechanistic separation between variation and selection steps, perhaps explaining biology's use of separate polymers, DNA and proteins.

Keywords: Darwinian evolution; competitive exclusion; driven nonequilibrium; survival of the fittest.