Individuals of different species often need similarconditions of existence, even in spite of significant differences in the organization. As a result, competition arises between them. What is interspecific struggle, examples of this phenomenon and its significance for evolutionary processes, we consider in our article.
During the entire period of development of evolutionary viewsthere were many opinions about the driving forces of this process. At the moment, the main are three. This is hereditary variability, on the basis of which useful attributes are fixed in the genotype, the struggle for existence and its consequence is natural selection. The essence of these processes is simple. In nature, individuals fight for better conditions of life, as a result of which the fittest of them survive. Their useful signs and their changes are fixed in the genetic apparatus and transmitted by inheritance.
The struggle for existence can occur between individuals of the same species. For example, in the mating season deer compete in the volume of the rut, attracting as many females as possible.
Interspecies struggle for existence, exampleswhich we will consider, arises in the case when ecological niches, distribution areas or trophic needs intersect. So, swallows and starlings prefer to eat the same kinds of insects. As a result, trophic competition arises.
There is another kind of struggle - withadverse conditions. Its result is the appearance in organisms of various adaptation adaptations. So, plants of arid territories have a long root and reduced leaves, like a rolling field. Primroses survive a hot period due to an underground modification of the shoot - the bulb.
As a result of this type of competition,certain relationships arise between individuals of different systematic groups. So, the basis of the relationship between the predator and the victim is the interspecies struggle for existence. Examples of it are especially common among animals. It is pronounced, if one object claims several types.
Thus, a hare in the forest is a desired victim of a wolf,hawks, foxes, martens and owls. Most often there is no open struggle between predators. It happens indirectly. As a result, the victory will be won by the "hunter", who has the most progressive features of the structure for effective attack. This is a quick run or flight, sharp and powerful teeth and claws.
Interspecific struggle, examples of which wereon the one hand, leads to the death of weak individuals. And on the other - it inevitably leads to progress. The victim improves the methods of shelter, and the predator - attacks.
Plants of different species also compete betweenand more acute than animals. This is because all autotrophs for survival need the same conditions. These include the presence of sunlight, moisture, fertile soil. In this case, the interspecific struggle begins.
Examples of such relationships are bright coloringcorollas, intensity of aroma, taste of nectar of flowers of different species. It is these signs that attract insects. In those plant species that are inferior to the rest, the process of pollination will not occur, fruits and seeds will not form. This will inevitably lead to the disappearance of the species.
Presence of thorns in hawthorn, barberry androse hips - also the result of interspecific struggle. For a long time, the bright and delicious fruits of these plants were eaten by animals. During the evolution of those specimens survived, small roughnesses on the shoots turned into pronounced spines.
For the territory of growth is also conductedinterspecific struggle. Examples of it are most pronounced in artificial ecosystems. Without human intervention, cultural plants are quickly replaced by weeds. This happens because the former develop under the condition of systematic care: irrigation, loosening of the soil, etc. And the weeds have a number of devices that allow them to grow actively under the most unfavorable conditions.
For example, everyone knows the rhubarb has rhizomes.This subterranean modification of the shoot consists of elongated interstices with bundles of accessory roots. Getting rid of the leaves, which are particularly hard, the plant itself remains unscathed and again shoots.
The consequence of the intraspecific struggle for existenceis natural selection. As a result, only the strongest remain viable. The struggle among individuals of different systematic groups leads to an intensification of intraspecific competition. All this inevitably leads to progressive evolutionary changes.
