Editing Biological interaction (section)

==== Mutualism ====

{{main|Mutualism (biology)}}

Mutualism is an interaction between two or more species, where species derive a mutual benefit, for example an increased [[carrying capacity]]. Similar interactions within a species are known as [[Co-operation (evolution)|co-operation]]. Mutualism may be classified in terms of the closeness of association, the closest being symbiosis, which is often confused with mutualism. One or both species involved in the interaction may be [[wikt:obligate|obligate]], meaning they cannot survive in the short or long term without the other species. Though mutualism has historically received less attention than other interactions such as predation,<ref name="Begon96">Begon, M., J.L. Harper and C.R. Townsend. 1996. ''Ecology: individuals, populations, and communities'', Third Edition. Blackwell Science, Cambridge, Massachusetts.</ref> it is an important subject in ecology. Examples include [[cleaning symbiosis]], [[gut flora]], [[Müllerian mimicry]], and [[nitrogen fixation]] by bacteria in the root nodules of [[legumes]].{{cn|date=May 2023}}