Current Perspectives in the Study of Mutualism

On the Kenyan savanna, a colony of tiny ants protects a shrubby tree from an elephant in search of tasty leaves. The ants swarm off the tree and climb inside the trunk of this giant foe. Surprisingly, the small but painful stings deter the elephant, and the tree is left alone for another day. In exchange for herbivore protection, the tree provides a home for the ants in the form of hollow thorns, and food from glands on its leaves. Mutualisms—interactions among different species with net fitness benefits to all partners—are fascinating and engaging. As humans we find the concept appealing, in the same way that we are drawn to ideas of cooperation and altruism. However, mutualism is not just an attractive idea, and the new volume edited by Judith Bronstein highlights how pervasive mutualisms are in every aspect of life, as well as how essential they are in ecosystem function. The book provides a comprehensive overview of conceptual treatments of the ecology and evolution of mutualism.