Genome sequencing has revolutionized genetics. It also requires new mathematical tools to help life scientists make sense of enormous amounts of data. Applying new math, Kristina Crona, an American University assistant professor who researches in the area of mathematical biology, and her colleagues show how ranking pathogen mutants can help scientists understand how mutants evolve to resist drug treatments. This line of research could have implications for the treatment of diseases that can resist drug treatments, such as HIV and malaria.