DNA mutations (changes in the genetic code) are typically associated with negative outcomes. However, DNA mutations are not necessarily bad. By introducing novel combinations of the genetic code, DNA mutagenesis provides the cell with fresh ingredient from which novel functions emerge. How cells balance the pros and cons of DNA mutagenesis remain poorly explored. We are characterizing molecular pathways that generate mutations to understand how they operate in the face of competing DNA repair pathways. Results from our work will not only reveal fundamental mechanisms underlying genetic adaptation but also suggest new strategies for improving the effectiveness and safety of new and existing gene-editing technologies.