Biology subjects

Cheong, K. H.

Publications and source records attributed to Cheong, K. H..

2 recordsLinked to original sources

bioRxiv2021

Alternating lysis and lysogeny is a winning strategy in bacteriophages due to Parrondo's Paradox

Temperate bacteriophages lyse or lysogenize the host cells depending on various parameters of infection, a key one being the host population density. However, the effect of different propensities of phages for lysis and lysogeny on phage fitness is an open problem. We explore a nonlinear dynamic evolution model of competition between two phages, one of which is disadvantaged in both the lytic and lysogenic phases. We show that the disadvantaged phage can win the competition by alternating between the lytic and lysogenic phases, each of which individually is a "loser". This counter-intuitive result recapitulates Parrondos paradox in game theory, whereby individually losing strategies can combine to produce a winning outcome. The results suggest that evolution of phages optimizes the ratio between the lysis and lysogeny propensities rather than the phage reproduction rate in any individual phase. These findings are expected to broadly apply to the evolution of host-parasite interactions.

bioinformatics↗

bioRxiv2017

The paradoxical sustainability of periodic migration and habitat destruction

Some species and societies engage in sustainable habitat destruction by periodically alternating between a low-growth migratory lifestyle and high-growth but destructive behavior. Examples include nomadic pastoralism and shifting cultivation, practiced by humans for millenia. Although specific models have been developed for species or societies which practice periodic migration and habitat destruction, theoretical insight into such phenomena as a whole is lacking. Here we present a general model of populations which alternate between migratory but negative-growth nomadism and destructive colonialism which yields high but short-term growth. Despite both strategies individually resulting in extinction, we demonstrate that a population can sustainably colonize an arbitrarily large network of habitats by alternating between the two. This counter-intuitive result can be interpreted in terms of both Parrondos paradox and the exploration-exploitation dilemma, suggesting answers to the question of sustainable development.

ecology↗