專題演講

2018/01/15(Mon)     14:00 -15:00    1st Floor(P101 meeting room)

Title

Statistical mechanics and collective effects in the rapid evolutionary dynamics of bacteria-virus ecosystems.

Speaker

Dr. Hong-Yan Shih

Department of Physics, University of Illinois at Urbana-Champaign

Abstract

I present two examples that demonstrate how statistical mechanics techniques and concepts can be used to quantify how evolution can profoundly influence ecological systems. In the first, I use statistical mechanics to predict anomalous phase relationships in predator and prey ecosystems, as a result of fast response to strong selection among distinct strains from point mutations. In the second, I study marine cyanobacteria and their predator cyanophages, which carry photosynthesis genes. I develop a spatially-extended individual-level model of the ecosystem and show that Monte Carlo simulation predicts that a collective state emerges through the gene flow between bacteria and viruses, resulting in the improvement of photosynthesis genes and the enlargement of the range and stability of the ecosystem. This mechanism shows that non-equilibrium spatio-temporal antagonistic interactions between organisms, on scales ranging from genomes to the environment, can drive the emergence of collective stability and diversity in predator-prey ecosystems.