mutualism

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Related to mutualistic: Symbiotic Relationships

Mutualism

An interaction between two species that benefits both. Individualsthat interact with mutualists experience higher sucess than those that do not.Hence, behaving mutualistically is advantageous to the individual, and it doesnot require any concern for the well-being of the partner. At one time,mutualisms were thought to be rare curiosities primarily of interest to naturalhistorians. However, it is now believed that every species is involved in oneor more mutualisms. Mutualisms are thought to lie at the root of phenomena asdiverse as the origin of the eukaryotic cell, the diversification of floweringplants, and the pattern of elevated species diversity in tropical forests.

Mutualisms generally involve an exchange of substances or services thatorganisms would find difficult or impossible to obtain for themselves. Forinstance, Rhizobium bacteria found in nodules on the roots of manylegume (bean) species fix atmospheric nitrogen into a form (NH3)that can be taken up by plants. The plant provides the bacteria with carbon inthe form of dicarboxylic acids. The carbon is utilized by the bacteria asenergy for nitrogen fixation. Consequently, leguminous plants often thrive innitrogen-poor environments where other plants cannot persist. Anotherwell-known example is lichens, in which fungi take up carbon fixed duringphotosynthesis of their algae associates.

A second benefit offered within some mutualisms is transportation. Prominentamong these mutualisms is biotic pollination, in which certain animals visitflowers to obtain resources and return a benefit by transporting pollen betweenthe flowers they visit. A final benefit is protection from one's enemies.For example, ants attack the predators and parasites of certain aphids inexchange for access to the aphids' carbohydrate-rich excretions(honeydew).

Another consideration about mutualisms is whether they are symbiotic. Twospecies found in intimate physical association for most or all of theirlifetimes are considered to be in symbiosis. Not all symbioses are mutualistic;symbioses may benefit both, one, or neither of the partners.

Mutualisms can also be characterized as obligate or facultative (dependingon whether or not the partners can survive without each other), and asspecialized or generalized (depending on how many species can confer thebenefit in question).

Two features are common to most mutualisms. First, mutualisms are highlyvariable in time and space. Second, mutualisms are susceptible to cheating.Cheaters can be individuals of the mutualist species that profit from theirpartners' actions without offering anything in return, or else otherspecies that invade the mutualism for their own gain.

Mutualism has considerable practical significance. Certain mutualisms playcentral roles in humans' ability to feed the growing population. It hasbeen estimated that half the food consumed is the product of bioticpollination. See Ecology, Plant pathology

mutualism

[′myü·chə·wə‚liz·əm]
(ecology)
Mutual interactions between two species that are beneficial to both species.
References in periodicals archive ?
Important "fertilizers" for mutualistic microbes are fermented foods, fiber, and phytonutrients.
Traps of carnivorous pitcher plants as a habitat: composition of the fluid, biodiversity and mutualistic activities.
30 inside the building and her works will eventually be on display in the lobby, creating a mutualistic relationship with the building.
These mutualistic and antagonistic relationships are constantly changing and require a move for each counter move.
Interest in mutualistic symbiotic relationships between luminescent bacteria (Vibrio fischeri) and their sepiolid cephalopod hosts such as the Hawaiian bobtail squid, Euprymna scolopes, has recently increased (e.
Although glandular hairs have probably evolved as a defense against herbivores and pathogenic fungi (Levin 1973, Duffey 1986), they can also mediate mutualistic interactions between plants and spiders or other predators (Dolling & Palmer 1991; Romero et al.
Pragmatics and corpus linguistics; a mutualistic entente.
It would be valuable to extend the taxonomic breadth of such studies and also to consider the importance of biotic interactions, such as pathogenic or mutualistic fungi, or insect or vertebrate herbivory, in structuring plant communities.
However, the development of nucleic acid based detection methods like 16S rRNA sequence analysis, and the availability of gnotobiotic (germ free) experimental laboratory animals, have served as broad tools to assess these mutualistic partnerships (5,8).
magellanicus abundance, because some scallop species maintain a mutualistic relationship with sponges that helps them escape predation.