A pair of geologists with the University of Cambridge has found a possible link between the evolution of ancient rootless plants and a marked increase in the production of ancient mud rock (fine-grained rock formed from silty clay deposits). In their paper published in the journal Science, William McMahon and Neil Davies describe their study and analysis of published papers reporting work with mud rock, and how they connected its increase to the arrival of rootless plants. Woodward Fischer with the California Institute of Technology offers a Perspectives piece on the work done by the team in Britain in the same journal issue.