Trace molecules emerge as chemical 'keystones' that steer life's communities‎

In nature, the rarest ingredient can be the one that holds everything together. In a new article published in Trends in Ecology & Evolution, Dr. Erika C. Freeman of the Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB) in Berlin argues that a handful of scarce molecules can shape entire living communities, far out of proportion to how little is present. These are what ecologists call "keystone molecules."