community ecology Mutualism

In attempting to unravel Darwin’s entangled bank and understand how these interactions form the basic structure of communities, many popular accounts of community ecology focus on extravagant antagonistic displays between species. Although aggressive behaviours are important interspecific interactions, the amount of attention that is focused on them may create the incorrect impression that they are more important than other types of interaction. Mutualistic interactions between species are just as integral to the organization of biological communities as antagonistic relationships, with some mutualistic interactions forming the most basic elements of many communities.

In many mutualistic relationships, one species acts as the host, and the other plays the role of visitor or resident. Plants are hosts for insects that pollinate them or eat their fruit and for microorganisms that attach themselves to their roots. In other mutualisms, such as flocks of birds that include a mixture of species, no species acts as host. Mutualisms also vary in the benefits the participants derive from the interaction. An individual may gain food, protection from enemies, a nesting site, or a combination of benefits. These benefits may vary from one population to another, thereby causing mutualistic relationships that exist between the same species to evolve in different directions in different populations.