According to Darwin's theory, the struggle for existence - a different relationship of organisms with environmental factors and with each other.In other words, it's not just a straight battle between predator and prey, accompanied by bloodshed and death.
Darwin identified three forms of the struggle for existence.
Intraspecific confrontation is most acute for.This is mainly due to the fact that all individuals need to be identical, and thus significantly limited resources.These include, in particular, include food, shelter, living space area for breeding.Each type is inherent in complex devices that can help reduce the probability of collision of individuals (a complex system of hierarchical relationships in a flock or herd, clearly marking the boundaries of their own territory, etc.).At the same time, such devices are useful for all species in general, often bring harm to specific individuals, causing their death.For example, a hare with a deficit of feed drives away a good portion of the competitor
struggle for existence and is the species.It is characterized by an acute course when the species belong to the same genus and therefore require similar conditions.An example might be a gray rat, which is much larger and more aggressive than black.The clashes first completely superseded by the second with human settlements.Thus the black rat, for example, has different powers.It is better than gray, runs across the ropes on ships from the shore and back.
So, America had introduced black rats Magellan and Columbus and Vasco da Gama brought them in Africa.Resettlement of this kind on Pacific islands Far East contributed to the Mariners.Thus, the struggle for survival has led to the fact that the gray rat inhabits territory within continents, and black - forest areas, islands and narrow area of the port area.
This type of collision involves the use of one kind of another unilaterally.Such relationships are built according to the "predator-prey", "herbivore-plant", "host-parasite".These relations have a significant impact on intra-fight.Thus, for example, the predator fox increases competition within a species of hares (victims).The fight win only those individuals who are able to run fast, well confuse the trail.Moreover, among the foxes survive good hunters.
struggle for existence may be favoring some species to others, not harming yourself.Thus, for example, mammals and birds carry seeds and fruit.There is also a mutual adaptation of certain types of one another (for example, pollinators and flowers).As a result, contributes to the evolution of the struggle of two types, causes the appearance of mutual adaptation.
at strengthening the fight within a species is a significant impact and the opposition hostile environments inorganic nature.This occurs mainly in the fact that individuals within a species are competing for heat, light, food and so forth.For example, in the tundra dwarf trees have shape, but they do not compete with other plants.The winners are the most viable individuals, those with the most efficient metabolism occurs, other physiological processes.If there is a transfer of the biological characteristics of inheritance, it leads to an improvement in adaptability.