Even long before humans appeared on Earth, animals and plants united among themselves in a kind of unions. So, for example, termites and ants "domesticated" about 2 thousand species of living organisms. Sometimes the relationship between different species is so strong that they eventually lose the ability to exist without each other.
Several types of coexistence
To understand that this is a "mutually beneficial relationship", it would be useful to consider it in context by comparing it with other species.
There are several of them in nature:
- Relationships that are not beneficial to either partner.
- Negative for one organism and indifferent for another.
- Positive for one and indifferent for the other.
- Indifferent to both sides.
- Mutually beneficial relationships between organisms.
- Those that are beneficial for one species and disadvantageous for another.
Next, for comparison with mutually beneficialrelationships, all kinds will be discussed in more detail.
Relationship without reciprocity
The first are called competition. It is the stronger, the closer the needs of organisms are to the condition or factor for which they compete. For example, the struggle for females, the displacement of one species of birds by another.
The second ones, which are not very common, are called "amensalism" (in Latin - "mad", "reckless"). For example, when a light-loving plant falls under the canopy of a dark forest.
Thirds are also quite rare. This is, firstly, commensalism, which in French means "companionship." That is, freeloading, in which the body eats leftovers from the “table” of another. Examples: a shark and its accompanying small fish, a lion and a hyena. Secondly, synoikia (in Greek "cohabitation"), or lodging, when some individuals use others as a shelter.
The fourth type suggests that organisms occupy similar habitats, but practically do not affect each other, how. For example, moose and squirrels in the forest. It is called neutralism.
Symbiosis, predation and parasitism
The fifth type is a symbiotic relationship. They are characteristic of those organisms that have different needs, while they successfully complement each other. This is an example of a mutually beneficial relationship between organisms.
Their prerequisite is cohabitation, a certain degree of coexistence. Symbiotic relationships are divided into three types, they are:
- Protocooperations.
- Mutualism.
- Actually, symbiosis.
More on them below.
As for the sixth type, it includes predation and parasitism. Predation is understood as a form of relationship between representatives of different species, from which the predator attacks the prey and feeds on its flesh. In a broad sense, this term reflects any eating, complete or partial, without an act of killing. That is, this includes the relationship between forage plants and animals that eat them, as well as parasites and hosts.
With parasitism, two or more organisms that are not evolutionarily related to each other, genetically heterogeneous coexist for a long time, being in antagonistic relationships or in symbiotic one-way. The parasite uses the host as a food source and habitat. The first imposes on the second fully or partially the regulation of their own relationships with the environment.
In some cases, the adaptation of parasites and their hosts leads to a mutually beneficial relationship of the type of symbiosis. There is an opinion among scientists that in most cases, symbiosis grew out of parasitism.
Protocooperation
This kind of mutually beneficial relationship literally means "primary cooperation". It is useful to both species, but is not mandatory for them. In this case, there is no close relationship between specific individuals. For example, it is a mutually beneficial partnership between flowering plants and their pollinators.
Most flowering plants are unable toform seeds without the participation of pollinators, whether insects, birds or mammals. For their part, the latter are interested in the pollen and nectar that serve as food for them. However, neither the pollinator nor the plant cares what kind of partner it will be.
Examples are: pollination of various plants by bees, dispersal of seeds of some forest plants by ants.
Mutualism
This is a kind of mutually beneficial relationship in which there is a stable cohabitation of two organisms belonging to different species. Mutualism is very widespread in nature. Unlike proto-cooperation, it involves a strong relationship between a particular plant species and a particular pollinator. Surprisingly subtle mutual adaptations of the animal and the flower that it pollinates are formed.
Here are some examples of mutualism.
Example 1. This is a bumblebee and a clover. The flowers of this plant can be pollinated only by insects of this species. This is due to the long proboscis of the insect.
Example 2. Nutcracker, which feeds exclusively on cedar pine nuts. She is the only distributor of her seeds.
Example 3. Hermit crab and sea anemone. The first lives in the shell, and the second settles on it. The anemone's tentacles are equipped with stinging cells, which create additional protection for the cancer. Cancer drags her from place to place and thereby increases the territory of her hunting. In addition, the sea anemone consumes the remains of a hermit crab meal.
Actual symbiosis
We are talking about an inseparable mutually beneficial relationship between two species, which implies the obligatory closest cohabitation of organisms, sometimes in the presence of elements of parasitism. Perhaps the most interesting example of such a mutually beneficial relationship between plants is the lichen. Despite the fact that it is usually perceived as a whole, it consists of two plant components - a fungus and an algae.
It is based on intertwining threads of the fungus, which are called "hyphae". They are densely intertwined on the surface of the lichen. And under its surface, in a loose layer, among the threads, there are algae. Most often they are green unicellular. Less common are lichens, where blue-green multicellular algae are present. Sometimes suckers grow on the hyphae, penetrating inside the algae cells. Cohabitation is beneficial for both of its participants.
The fungus supplies the algae with water in which mineral s alts are dissolved. And from her in return he receives organic compounds. These are mainly carbohydrates, which are a product of photosynthesis. Algae and fungus are very closely fused in lichen, representing a single organism. Most often, they breed together.
Mycorrhiza means "fungal root"
It is known that boletus is found in birch forests, and boletus grows under aspens. Near certain types of trees, cap mushrooms do not grow by chance. The part of the mushroom that is harvested is its fruiting body. And underground there is a mycelium, otherwise calledmycelium. It has the form of filamentous vultures penetrating the soil. From the surface layer, they stretch to the ends of the tree roots. Vultures wrap around them like felt.
Rarely, you can find such forms of symbiosis, in which fungi settle in the root cells themselves. This is especially pronounced in orchids. The symbiosis of fungi and roots of higher plants is called mycorrhiza. Translated from Greek, it means "mushroom root". Mycorrhiza with mushrooms forms the vast majority of trees growing in our latitudes, as well as many herbaceous plants.
The fungus uses carbohydrates for its nutrition, which are secreted by the roots. The higher plant from the fungus receives products formed as a result of the decomposition of organic nitrogenous substances in the soil. It is also suggested that fungi produce a vitamin-like product that enhances the growth of higher plants. In addition, the mushroom root cover, with its many branches in the soil, greatly increases the area of the root system that absorbs water.
The following are examples of mutually beneficial relationships between animals.
Hunting together
It is known that dolphins, hunting for fish, unite in herds, and wolves hunt moose, straying into a flock. When animals of the same species help each other, such mutual assistance seems natural. But there are situations when "strangers" unite for hunting. The Central Asian steppes are inhabited by the corsac fox and the bandage, a small animal similar to a ferret.
Both of theminterested in a large gerbil, which is quite difficult to catch. The fox is too fat to get into the hole with the rodent. The bandage can do this, but it's hard for her to catch it on the way out. After all, while it squeezes under the ground, the animal runs away along the emergency passages. In the case of cooperation, the dressing drives the gerbil to the surface, and the fox is already on duty outside.
With a heron on her back
Here is another example of mutually beneficial animal relationships. It is not uncommon for herons to perch on the backs of animals such as buffaloes or elephants. In the jungle, large animals are plagued by many parasites, but it is difficult for them to get rid of gadflies, horseflies, ticks, flies, fleas.
And then cleaner birds come to their aid. Sometimes there are up to twenty herons on the back of an elephant. Animals have to endure some inconvenience, but they allow birds to feed, moving around the body, if only they rid them of parasites. Another service of birds is a danger alert. Seeing the enemy, they take off with a loud cry, giving their "master" a chance to escape.
