Network-thinking in evolutionary biology: can we still uncover surprising interactions involving the microbial world ?

It is well-known that there are interactions everywhere in the living world. This seems very much like old scientific news. However, I will argue that, when biological evolution is investigated in ways that focus on microbes and interactions, some rather unexpected, evolutionary meaningful, interactions can still be uncovered. In this talk, I will introduce some recently published works from my lab and go through three, quite distinct cases of such surprising interactions. First, I will show how the use of similarity networks sheds light on a diversity of remodelled genes (symbiogenetic, chimeric, etc.), which arise from interactions between molecular components within genomes. Then, I will describe unexpected interactions between phages and bacteria, suggested by the prediction of novel quorum-sensing systems. Finally, I will provide original evidence that protein-protein interaction networks associated with ageing in humans are possibly impacted by 'age-distorters', suggesting that dozens of viruses can alter or manipulate human ageing. I will explain why such findings expand current evolutionary studies of ageing and encourage the development of original co-evolutionary analyses of ageing.