The evolution of multicellularity created new ecosystems, fundamentally changing Earth’s ecology (Szathmáry & Smith, 1995). While multicellularity has evolved numerous times in diverse lineages (Knoll et al. 2011), no prior work has directly examined the impact of this major evolutionary transition on multicellular diversity. Using long-term experimental evolution, we show that the evolution...
Drug resistant pathogens are a wide-spread and deadly phenomenon that infect nearly 3 million individuals in the United States each year. If microbial resistance continues to develop at the current rate, bacterial infections are expected to surpass cancer as the leading cause of death worldwide by 2050. Novel approaches to designing therapy that explicitly take into account the adaptive nature...
Evolution can be viewed as a game where the object is to keep playing. From this perspective, focus is brought to the properties of lineages that enable their success over long spans of evolutionary time, rather than the phenotypes and performance of individuals in the contemporary environment. One property required for long-term evolutionary success is the ability of a lineage to translate...
Many cellular populations are tightly packed, including microbial colonies and biofilms, or tissues and tumours in multicellular organisms. However, little is known about how ensuing mechanical cell-cell interactions reshape evolutionary dynamics and critical outcomes, such as drug resistance. Here, I will show how growth-induced collective motion inherently suppresses the differential...
Microbes inhabit natural environments that are remarkably dynamic, with sudden environmental shifts that require immediate action by the cell. The genetic control of cellular responses therefore evolve according to the specific demands of their environment, resulting in different strategies such as transcriptional regulation or stochastic switching. However, when microbes are exposed to...
History, chance, and selection are the fundamental factors that drive and constrain evolution. We designed evolution experiments to disentangle and quantify effects of these forces on the evolution of antibiotic resistance. Previously, we showed that selection of the pathogen Acinetobacter baumannii in both structured and unstructured environments containing the antibiotic ciprofloxacin...
Eukaryotes and prokaryotes have distinct genome architectures, with marked differences in genome size, the ratio coding/non-coding DNA, and the abundance of transposable elements (TEs). As TEs replicate independently of their hosts, the proliferation of TEs is thought to have driven genome expansion in eukaryotes. However, prokaryotes also have TEs in intergenic spaces, so why do prokaryotes...
Plasmids are mobile genetic elements that horizontally transfer antibiotic resistance and virulence factor genes among bacteria. It's unclear if plasmids persist only through selection for the genes they carry or if they are infectious enough to persist as genomic parasites. Here we show that plasmids' infectious potential is severely underestimated by theoretical models and experimental...
