Professor Craig MacLean

Supernumerary Fellow, Professor of Evolution and Microbiology

My research investigates the evolutionary biology of antibiotic resistance in bacterial pathogens. The clinical use of antibiotics is arguably the single most important driver of increased longevity in industrialized societies since 1945. However, the widespread use of antibiotics has resulted in the rapid evolution of antibiotic resistance in bacteria populations, and this threatens to undermine the clinical utility of antibiotics. My research aims to understand the fundamental evolutionary processes that drive the spread and maintenance of antibiotic resistance. Some of the questions that we are working on are as follows:

  • What determines the fitness costs and benefits of resistance?
  • How do stress response pathways impact resistance evolution?
  • How do patterns of antibiotic use influence resistance evolution?
  • Why does resistance persist after antibiotic use is stopped?
  • What are the genomic drivers of resistance evolution?

To address these questions, we primarily use experiments in which populations of bacteria are challenged with adapting to antibiotics under controlled lab conditions. By using a combination of fitness assays, whole genome sequencing and mathematical modelling, it is possible to use this approach to gain a detailed understanding of the evolutionary drivers of resistance. The big challenge for us over the next few years will be to try and integrate our experiments with data on how resistance evolves in clinical settings.


I teach cell biology & genetics to first-year biologists and evolutionary biology.