The importance of ecological dynamics in evolutionary processes: A host-bacteriophage model revisited. (21st April 2022)

• Record Type: Journal Article
• Authors: Boldin, Barbara
• Is Part Of: Journal of theoretical biology. Volume 539(2022)
• Publication Date: 2022-04-21
• Subjects: Adaptive dynamics -- Ecological dynamics -- Evolution -- Bacteriophage -- Temperate virus -- Lysis -- Lysogeny -- Evolutionary branching; Biology -- Periodicals; Biological Science Disciplines -- Periodicals; Biology -- Periodicals; Biologie -- Périodiques; Theoretische biologie; Biology; Periodicals; 571.05
• DOI: 10.1016/j.jtbi.2022.111057
• Languages: English
• ISSNs: 0022-5193

Abstract

Highlights: Importance of understanding ecological interactions as a driver of evolution. Ecological interactions drive evolution of lysis propensity in temperate bacteriophages. In equilibrium host-phage environments, evolution decreases propensity for lysis. Evolution may drive host-phage systems out of equilibrium environments and into a periodic regime. In periodic environments, evolution may either lead to full lysogeny or to an evolutionarily stable coalition of two phage strains. Abstract: A recent study of adaptive dynamics of lysis propensity in temperate phages suggested that full lysogeny emerges as the outcome of bacteriophage evolution in a simple host-phage system. The conclusion is based on the premise that mutant strains necessarily appear in equilibrium host-phage environments. Revisiting the model, we show that the ecological system exhibits richer asymptotic dynamics and that, in a certain parameter regime, evolution may in fact drive lysis propensity towards an evolutionary singularity in which a non-zero proportion of phages initiate infection in a lytic cycle. These singularities act as points of evolutionary diversification, leading to periodic coexistence of two distinct phage strains on the evolutionary time-scale. One of the two strains in the dimorphic evolutionary singularity is fully lysogenic (in the sense that cell infection always leads to lysogeny), while the other is partially lytic. Our study thus highlights the importance of ecological interactions as a driver of evolution.