How ancient RNA survives and what we can learn from it

Although normally transient, RNA can persist postmortem when preserved by cold, desiccation or chemical treatment. In this Comment, we discuss how ancient RNA enables the study of gene expression of (pre)historic viruses, plants and animals going back at least as far as the last Ice Age. Friedlander and Gilbert introduce the study of ancient RNA of viruses, plants and animals, and how it can inform us of (pre)historic gene expression.