Definition
What is mutualism?
Mutualism is a type of symbiosis, or close interaction between species, in which each partner gains something it needs, such as food, protection, transport or help with reproduction. It contrasts with commensalism, where only one partner benefits, and parasitism, where one benefits at the other's cost. Some mutualisms are obligate, meaning one or both partners cannot survive without the other, while others are facultative: helpful but not essential.
Examples are everywhere. Bees collect nectar and pollen and in return carry pollen between flowers. Clownfish shelter among the stinging tentacles of sea anemones, protected by a coat of mucus, and their bright colors lure in fish that the anemone catches. Termites depend on protozoa in their gut to digest the cellulose in wood. Lichens combine a fungus with algae or cyanobacteria, and the roots of many plants partner with fungi as mycorrhizae, trading sugars for water and minerals. Legumes such as peas and beans house nitrogen-fixing Rhizobium bacteria in their root nodules.
Mutualisms can underpin whole ecosystems. Reef-building corals rely on photosynthetic algae in their tissues, and when heat stress breaks this partnership the corals bleach and may die.
Word parts
Where does the word “mutualism” come from?
- mutu-
- exchanged, reciprocalLatin mutuus
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Terms that go with it
- SymbiosisSymbiosis is a close, long-lasting relationship between two different species that may benefit both, benefit one, or benefit one at the other's expense.
- MycorrhizaA mycorrhiza is a mutually beneficial partnership between a fungus and plant roots, trading water and soil minerals for sugars made by the plant.
- PollinationPollination is the delivery of pollen to the female reproductive parts of a seed plant, the step that makes fertilization and seed formation possible.
- MicrobiomeA microbiome is the community of bacteria, fungi, viruses and other microbes, with their genes, that lives in a particular place, such as the human gut.
- Coral bleachingCoral bleaching is the paling of stressed corals as they lose the tiny symbiotic algae inside their tissue, most often because the water is too warm.
- Nitrogen cycleThe nitrogen cycle is the set of mainly microbial processes that move nitrogen between atmospheric gas, ammonium, nitrate and living organisms.
Sources
Checked against
Written for biofideX in plain words, after checking these references:
- OpenStax Biology 2e, 45.6 Community Ecology
- National Geographic Education: Symbiosis: The Art of Living Together
- National Geographic Education: Keystone Species
- Wiktionary: mutuus (Latin)
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