Most evolutionary models assume that genetic recombination always occurs at the same rate. Applying an alternative theory, the EU-funded 'The evolution and implications of fitness-associated genetic mixing - a theoretical study' (FAGM) project has produced simulations based on plastic mixing. Researchers looked at three sources of new genetic combinations — sexual reproduction, outcrossing and dispersal. The scientists also extended their previous work on the evolution of antibiotic resistance and use of antibiotics in hospitals. They investigated Candida albicans, the most common fungal pathogen in humans. Results showed that both fitness-associated outcrossing and fitness associated dispersal can evolve under an extremely wide parameter range. Stress-induced mutagenesis occurs in both constant and changing environments. Moreover, if beneficial mutations occur, stress-induced hypermutation, especially common in microbial populations, is advantageous and is likely to evolve in bacterial populations. Project results indicate that genetic variation is not uniformly distributed in a population and this has wide-ranging implications on future models in evolution and ecological studies. From a practical point of view, the work is relevant to antimicrobial use as well as plants and animals under stress in a rapidly changing environment.
Stress, evolution, genetic recombination, plastic mixing, antibiotic resistance, mutagenesis, hypermutation