PIMS/CSC Distinguished Speaker Series: Natalia L. Komarova

Cancer comes about by a sequence of mutations that change the cells' fitness and create advantageous phenotypes. These phenotypes displace other cells and spread, thus winning the evolutionary competition. It is possible that in order to create those advantageous mutants, several different mutations have to be accumulated in a cell, such that each individual mutation is disadvantageous, and together they comprise a fitness advantage. In the literature, this is often called "crossing a fitness valley". In this talk I will present a novel mechanism by which such fitness valleys can be crossed. It envolves the notion of cooperation among the cells, where shared benefits are received through "division of labor". I will show how in such context, cooperation can speed up the evolutionary process. Moreover, the emergence of cheaters that destroy cooperation dynamics can “unite” all mutations within one individual on a fast time scale. Paradoxically, the presence of such cheaters happens to accelerate evolution even more.