Individuals of different species often need similar living conditions, even despite significant differences in organization. As a result, rivalry arises between them. What is interspecific struggle, examples of this phenomenon and its significance for evolutionary processes, we will consider in our article.
Drivers of Evolution
Over the entire period of evolutionary views, there have been many opinions about the driving forces of this process. At the moment, the main ones are three. This is hereditary variability, on the basis of which useful traits 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 living conditions, as a result of which the fittest of them survive. Their useful traits and their changes are fixed in the genetic apparatus and are inherited.
Types of Struggle for Existence
The struggle for existence can occur between individuals of the same species. For example, in the mating season, deer compete in rutting volume, attracting as many females as possible.
The interspecific struggle for existence, examples of which we will consider, arises when ecological niches, distribution areas, or trophic needs intersect. So, swallows and starlings prefer the same species of insects for food. As a result, trophic competition arises.
There is another type of struggle - with adverse conditions. Its result is the appearance in organisms of various adaptive devices. So, plants in arid territories have a long root and reduced leaves, like a tumbleweed. Primroses are experiencing a hot period due to the underground modification of the shoot - the bulb.
Interspecific struggle: examples from the animal kingdom
As a result of this type of competition, certain relationships often arise between individuals of different systematic groups. So, the basis of the relationship between the predator and the prey is the interspecific struggle for existence. Examples of it are especially common among representatives of animals. It is pronounced if several species apply for one object.
So, a hare in the forest is a welcome sacrifice of a wolf, hawk, fox, marten and owl. Most often, an open struggle between predators does not occur. It occurs indirectly. As a result, the victory will be won by the "hunter", who has the most progressive features of the structure for an effective attack. This is a quick run or flight, sharp and powerful teeth and claws.
Interspecific struggle, examples of which were given, on the one hand, leads to the death of weak individuals. And on the other - inevitably entails progress. The victim improves the methods of shelter, and the predator - attacks.
Interspecific struggle: examples from the plant kingdom
Plants of different species also compete with each other, more sharply than animals. This is because all autotrophs need the same conditions for survival. These include the presence of sunlight, moisture, fertile soil. In this case, interspecific struggle begins.
Examples of such relationships are the bright color of the corollas, the intensity of the aroma, the 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, pollination will not occur, fruits and seeds will not form. This will inevitably lead to the extinction of the species.
The presence of thorns in hawthorn, barberry and rose hip is also the result of interspecific struggle. For a long time, the bright and tasty fruits of these plants were eaten by animals. In the course of evolution, those specimens survived whose small roughnesses on the shoots of which turned into pronounced spikes.
Fight for territory
Interspecific struggle is also waged for the territory of growth. Examples of it are most pronounced in artificial ecosystems. Without human intervention, cultivated plants are quickly replaced by weeds. This happens because the former develop under the condition of systematic care: watering, loosening the soil, etc. And weeds have a number of adaptations that allow them to grow actively in the most adverse conditions.
For example, the well-known wheatgrass has rhizomes. This underground modification of the shoot consists of elongated internodes with bundles of additional roots. Getting rid of leaves that are particularly stiff, the plant itself remains unharmed and again sprouts.
The consequence of the intraspecific struggle for existence is natural selection. As a result, only the strongest remain viable. The struggle among individuals of different systematic groups leads to increased intraspecific competition. All this inevitably entails progressive evolutionary changes.