subject: Foreign-service Natural Resource [print this page] The mutualism is a biological interaction between individuals of different species where both benefit and improve their biological fitness . Similar actions that occur between members of the same species are called cooperation . Mutualism is distinguished from other interactions in which one species benefits at the expense of another, these are the cases of exploitation, such as parasitism , predation , etc..
The symbiosis may be a particular type of intimate mutualism, in which one party (or both) is strictly dependent on the other. Other types of symbiosis include cases of parasitism or commensalism .
The mutualistic interactions play a key role in ecology and evolutionary biology. For example, mycorrhizae are essential for 70% of terrestrial plants. Another important role of mutualisms is increased biodiversity , exemplified by the interactions between pollinators and flowers of plants angiosperms . Coevolution between angiosperms and insects has led to a proliferation of both types of organisms. 1 Unfortunately mutualism has not received much attention as other interactions such as predation and parasitism, its importance is equal to or greater than these. 2 3
In the process of mutualism is important to determine the degree of benefit of fitness, which is not easy, especially when interactions are not only between two species but a species can receive benefits from numerous other species. Such is the case with many pollination systems in which a plant species is pollinated by several different pollinators and these in turn are visiting or mutual with a variety of plants. It is best to categorize based on how mutualisms bond of association which can range from required (dependency) to optional (not mandatory). Dependence can also be mutual or one side only (eg a specialized pollinator in one kind of flower as she receives the benefits of more than one pollinator). 4
An example of obligate mutualism are the bacterial endosymbionts of insects that have a close relationship dating back millions of years. Insects can not survive without its symbionts. Such is the case aphid ( Acyrthosiphon pisum ) and its endosymbiont, bacteria Buchnera .
Mutual relations can be considered as a kind of barter or biological redeem 4 in which the species exchange resources (for example carbohydrates or inorganic compounds) or services (such as dispersion of gametes or offspring or protection from predators).
The resource-resource relationships in which one type of resource is exchanged for another is probably the most common type of mutualistic associations such as mycorrhizae in the roots of a plant and a fungus . The plant provides carbohydrates to the fungus in exchange for water and minerals, especially phosphates and nitrates . The rhizobial nitrogen-fixing plants and leguminous nitrogen exchange for carbohydrates.
Service-resource relationships are also common, such as pollination in the resources of nectar I pollen are exchanged for the service of dispersal of gametes (pollen) from the plant. Another example is that of the ants that protect aphids from predators (service) in exchange for honeydew or honeydew (resource) that is a byproduct of the aphids suck sap from the plant.
