Mutualisms

Mutualisms

Subject: Environment

Mutualism, Cooperation and Symbiosis:

• Cooperation is a broad label for beneficial interactions that can exist between two or more individuals of the same species or of different species. Therefore, mutualism, which refers to the positive interactions between creatures of different species, is a subset of the interactions that fall under the ambit of cooperation.
• Symbiosis translates roughly into ‘life companions’ and refers to organisms that live in close contact with each other. Symbiotic relationship can either be parasitic (where one organism benefits from the association and the other is harmed), commensal (where one benefits, but the other gains no benefit nor is it harmed), or mutualistic (where both organisms benefit from their interactions).

Examples:

• Plants rely on pollinators to ferry pollen between flowers for reproduction. Pollinators receive food (either as nectar or the pollen itself) as a reward for this service.
• Mutualisms are those between plants and nitrogen-fixing bacteria (where plants provide food and shelter to bacteria that convert atmospheric nitrogen into minerals that plants can absorb)
• Plants and fungi called mycorrhizae (where plants provide food and shelter to fungi that help the plants to absorb micronutrients like phosphorous and iron from soil).
• Humans and some gut bacteria such as specific strains of Escherichia coli or E. coli have mutualistic relationships where the human provides food and shelter to the bacteria, which provide their human hosts with vitamin K and some essential nutrients.
• Ants and termites with fungi, where the ants/termites literally cultivate fungi by providing specific fungi with food (usually cellulose from plant material like wood and leaves) to grow on and protect the fungi by weeding out or killing off competing fungi. The fungi, in turn, digest the cellulose and convert it into a form that the ants can eat.
• Between ants and aphids, where ants protect aphids from predators and the aphids reward the ants with drops of sweet sugary liquid called honeydew.
• Mutualisms between corals and photosynthetic organisms called zooxanthellae. The corals provide zooxanthellae with shelter and minerals, while the zooxanthellae provide the corals with oxygen, glucose, glycerol, and amino acids, which are products of photosynthesis.

Types of Mutualism: