 This study examined the role of epigenetic adaptation speeding mechanisms in the rapid evolution of yeast cells under arsenic exposure. The researchers found that the cells adapted quickly to the environment without requiring any phenotypic plasticity or mutation accumulation. They also identified causative mutations responsible for the adaptation and validated them through deep sequencing. The researchers then developed a mathematical model to explain how the mutations affected the growth phenotype and how the mutations interacted with each other. Their results suggest that the rapid adaptation was due to extensive positive pliotropy, whereby all beneficial mutations improved multiple fitness components simultaneously. This study provides evidence that epigenetic adaptation speeding mechanisms are important in the evolution of organisms under environmental challenge. This article was authored by R&B Guisland, Enneco Zorgo, Givantea Seimi, and others.