A New, Chemical View of Ecosystems

The biological world is awash in chemical signals. Ants lead their nest mates to food with winding trails of pheromones, plants exude aerosols to warn their neighbors of herbivores, and everything you experience as “smell” is a molecule latching onto your nose. Some molecular messages find their targets; most linger unread in the environment. But sometimes, other species — chemical eavesdroppers, bystanders or visitors — can pick up and interpret the signals in their own way. If the message is powerful enough, the impact can ripple out across an ecosystem. In 2007, biologists named these potent molecules after a popular concept in ecology. “Keystone species,” such as starfish in Pacific Northwest tidepools, aren’t abundant, but they have outsize effects on the food web — making those species as crucial to their ecosystems as a load-bearing keystone in an archway. If they’re removed, the idea goes, the entire ecosystem could collapse into a different form. “Keystone molecules,” then, a ... Read full article.