The role of aneuploidy in adaptive evolution

Experimental evidence indicates that aneuploidy – the presence of an abnormal number of chromosomes in a cell – contributes to adaptation in yeast, emergence of drug resistance in fungal pathogens, and tumorigenesis in cancer cells. However, the literature on adaptive evolution neglects the role of aneuploidy, focusing instead on other mechanisms for generation of genomic variation, e.g. mutation and recombination. Consequently, there is a critical need for an evolutionary theory of aneuploidy. To fill this gap, we are studying models of adaptive evolution under mutation and aneuploidy. We use these models to analyse results of experiments with yeast, to identify the conditions in which aneuploidy accelerates or decelerates adaptation, and to determine when high aneuploidy rates are likely to evolve. Our results can assist the design and analysis of evolutionary experiments, as well as the development of new treatments for fungal infections. Moreover, this research contributes to a shift in the understanding of aneuploidy and chromosome duplication not as inevitable cellular accidents, but as evolvable mechanisms for generation of genomic variation and adaptation.