Quantitative understanding of evolution is a prerequisite to successfully combat pathogens, pests and loss of biodiversity. For instance, identifying genetic variants which contribute to the emergence of drug resistance, a question with importance for the treatment of pathogens, and of cancer, is a challenge of understanding the evolution of these populations. Big Data provide new opportunities to study in detail how populations evolve. However, data alone, without theory and scalable algorithms to extract information from it, is not sufficient to make progress. The Mustonen Group develops computational algorithms and theory to better understand evolution. The work is cross-disciplinary and we have a record of successful research collaborations working together with clinicians and experimentalists.