Long before a person appeared on Earth, animals and plants united among themselves in peculiar alliances. For example, termites and ants “domesticated” about 2 thousand species of living organisms. Sometimes the relationship between different species is so strong that in the end they lose the ability to exist without each other.
Several types of coexistence
To understand that this is a "mutually beneficial relationship", it would be advisable to consider them in context, comparing with other types.
There are several of them in nature:
- Relationships that are disadvantageous to any of the partners.
- 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.
Further, for comparison with mutually beneficial relationships, all types will be considered in more detail.
Relationships Without Reciprocity
The first are called competition. It is the stronger, the closer the needs of the organisms are to the condition or factor for which they are competing. For example, the struggle for females, the displacement of one species of bird by another.
The second, which are not widely distributed, are called "amenismism" (in Latin - "crazy", "reckless"). For example, when a light-loving plant falls under the canopy of a dark forest.
Still others are also quite rare. This is, firstly, commensalism, which in French means "sotrapeznichestvo". That is, parasite, in which the body eats leftovers from the “table” of another. Examples: shark and small fish accompanying it, lion and hyena. Secondly, sinoykia (in Greek “cohabitation”), or lodging, when some individuals use others as a refuge.
The fourth type suggests that organisms occupy similar habitats, but practically do not affect each other, like. 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 mutually beneficial relationships of organisms.
Their prerequisite is cohabitation, a certain degree of coexistence. Symbiotic relationships are divided into three varieties, we are talking about:
- Protocoperations.
- Mutualism.
- Actually, a symbiosis.
More about them will be discussed below.
As for the sixth type, predation and parasitism are attributed to it. Under predation is understood the form of relations between representatives of different species, of which the predator attacks the prey and feeds on its flesh. In a broad sense, this term refers to all eats, complete or partial, without the act of killing. That is, this includes the relationship of fodder plants and the animals eating 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 unilateral. The parasite uses the host as a food source and habitat. The first entrusts to the second, in whole or in part, the regulation of their own relationships with the environment.
In some cases, the adaptation of parasites and their hosts leads to mutually beneficial relationships as a symbiosis. There is an opinion among scientists that in most cases, symbiosis has grown out of parasitism.
Protocooperation
This kind of mutually beneficial relationship literally means "primary cooperation." It is useful for both species, but is not required for them. In this case, there is no close relationship between specific individuals. For example, these are mutually beneficial partnerships between flowering plants and their pollinators.
Most flowering plants are not able to form seeds without the participation of pollinators, whether it be insects, birds or mammals. For their part, the latter are interested in pollen and nectar, serving as food for them. However, it does not matter to the pollinator or the plant exactly what the type of partner will be.
Examples are: pollination of various plants by bees, the spread of seeds of some forest plants by ants.
Mutualism
This is a type of mutually beneficial relationship in which there is a steady coexistence of two organisms belonging to different species. In nature, mutualism is very widespread. Unlike protocooperation, it involves a strong connection between a particular plant species and a specific pollinator. Surprisingly subtle mutual adaptations of the animal and the flower that they pollinate are formed.
Here are a few examples of mutualism.
Example 1. This is a bumblebee and 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. Cedar, which feeds exclusively on pine cedar nuts. She is the only distributor of her seeds.
Example 3. Hermit crab and sea anemone. The first lives in the sink, and the second settles on it. The tentacles of anemone are provided with stinging cells, which create additional protection for the cancer. Cancer drags her from place to place and thereby increases the territory of her hunt. In addition, sea anemone consumes the remains of the hermit crab meal.
Actually symbiosis
This is an inseparable, mutually beneficial connection between the two species, which presupposes 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 lichen. Despite the fact that it is usually perceived as a whole, it consists of two plant components - this is a mushroom and algae.
It is based on interwoven strings of the fungus called hyphae. They are tightly bound on the surface of the lichen. And under its surface, in a loose layer, among the threads, algae are located. Most often they are green unicellular. Less commonly seen are lichens, where blue-green multicellular algae are present. Sometimes suckers grow on hyphae, penetrating into the cells of algae. Cohabitation is beneficial for both of its members.
The fungus supplies algae with water in which mineral salts are dissolved. And in return, she receives organic compounds from her. These are mainly carbohydrates, which are the product of photosynthesis. Algae and mushroom are very closely compressed in lichen, representing a single organism. Most often they breed together.
Mycorrhiza means "fungus root"
It is known that birch forests are found in birch forests, and aspen trees grow under aspen trees. Near certain types of trees, hat mushrooms do not grow by chance. The part of the fungus that is collected is its fruiting body. And underground is the mycelium, otherwise called mycelium. It has the form of filiform vultures permeating the soil. From the surface layer they stretch to the ends of the tree roots. Vultures braid them like felt.
Less commonly, there are 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, this means "fungus root." Mycorrhiza with mushrooms forms the vast majority of trees growing in our latitudes, as well as many herbaceous plants.
The fungus uses carbohydrates that are secreted by the roots for their nutrition. The higher plant receives from the fungus products resulting from the decomposition of organic nitrogenous substances in the soil. It is also assumed that mushrooms produce a product similar to vitamins, which enhance the growth of higher plants. In addition, the mushroom cover on the root with its many branches in the soil significantly increases the area of the root system that absorbs water.
The following are examples of mutually beneficial relationships between animals.
Joint hunting
It is known that dolphins, fishing for fish, unite in herds, and wolves hunt moose, breaking off in a flock. When animals of the same species help each other, such mutual assistance seems natural. But there are situations when "outsiders" unite for hunting. In the Central Asian steppes, the fox fox and ligation, a small animal similar to a ferret, live.
Both of them are interested in a large gerbil, which is quite difficult to catch. The fox is too thick to fall into the mink to the rodent. A dressing can do this, but it’s hard for her to catch him at the exit. After all, while she squeezes underground, the animal runs away through the emergency doors. In the case of cooperation, the ligation expels the gerbil to the surface, and the fox is already on duty from the outside.
With heron on the back
Here is another example of mutually beneficial animal relationships. Herons are often piled on the backs of animals such as, for example, buffalo or elephants. In the jungle, large animals are annoyed by many parasites, but it is difficult for them to get rid of gadflies, horseflies, ticks, flies, fleas.
And then the cleaning birds come to their aid. Sometimes on the back of an elephant is up to twenty herons. Animals have to endure some inconvenience, but they allow birds to feed, moving throughout the body, if only they would save them from parasites. Another bird service is hazard warning. Seeing the enemy, they take off with a loud cry, giving a chance of salvation to their "master".