Effects of Pattern Formation in <i>Bacillus subtilis</i> Biofilms on Evolutionary Dynamics

Biofilms are a ubiquitous form of microbial growth where individual cells interact mechanically and chemically to allow collective behavior at the population level. This collective behavior often leads to the formation of patterns, of which one prominent example is wrinkling of the entire colony into the third dimension. Our experiments with Bacillus subtilis biofilms on agar surfaces suggest that there is a correlation between wrinkle formation and natural selection. Our goal is to investigate whether the presence or the absence of certain patterns such as wrinkles lead to different evolutionary dynamics. We will present results on how pattern formation affects natural selection and as well as how selection feeds back onto the organization of the pattern. These results could lend insight into drug resistance evolution in microbial biofilms.