When a grassland becomes a desert, or a clearwater lake shifts to turbid, the consequences can be devastating for the species that inhabit them. These abrupt environmental changes, known as regime shifts, are the subject of new research in Nature Ecology & Evolution which shows how small environmental changes trigger slow evolutionary processes that eventually precipitate collapse.
Until now, research into regime shifts has focused on critical environmental thresholds, or “tipping points,” in external conditions — eg when crossing a certain temperature threshold triggers a sudden shift to desertification. But the new model by Catalina Chaparro-Pedraza and SFI External Professor André de Roos, both at the University of Amsterdam, reveals how a small change in the external environment, with little immediate impact, can induce slow evolutionary changes in the species that inhabit the system. After what the researchers call a “considerable delay,” wherein species slowly evolve a new trait or behaviour over generations, the regime shift manifests as a delayed reaction. MORE
Header image: Two evolutionary spaces illustrate how a small change in environmental conditions with few immediate effects opens up a gradual path toward regime change. Credit: Andre de Roos.