The main result of evolution is the improvement of the adaptability of organisms to habitat conditions

There are not many left in the world of people whocontinue to believe in the biblical story of the creation of all life on our planet. Everything is familiar with the concept of evolution. Multiple evidence of the development of all living things on Earth leaves no doubt about the origin of the changes in the world around us. Who is Charles Darwin, even younger schoolchildren know. But when it comes to what is the result of evolution, there is no definitive answer.

Academic background

We begin, in fact, with the definition of the conceptevolution in biology. This word is derived from the Latin evolutio, which means literally "deployment". The process of evolution is often represented in the form of an unfolding spiral. In biology, this term refers to the irreversible process of development of the organic world in all aspects of its manifestation. The result of evolution is the diversity of the organic world and the improvement of the adaptability of organisms to environmental conditions.

Darwinism as the basis of the doctrine of evolution

The founder of the exercise - Charles Darwin (1809-1882) - formulated the following principles of evolutionary teaching:

• All species are capable of unlimited reproduction of their kind.
• The lack of life-supporting resources limits the unlimited growth of the species. Natural selection as a result of evolution is the limiting factor that regulates the number of organisms.
• Success, as well as the death of an individual in the struggle for existence, is selective. And he called this selectivity a natural selection.
• The main results of evolution - according to Darwin - is the improvement of the organism's fitness to the conditions of the biotope and, as a consequence, the increase in the variety of species.

Variety as a consequence

Since the results of evolution, according to Darwin,is the fitness of the organism, as a result of the action of natural selection, individuals that possess the most useful qualities for survival survive and thrive. Natural selection is the "creative" mechanism of evolution. The result is the appearance of new signs that increase the chances of the individual to leave prolific offspring and pass on to them these signs.

Evolution Material

If the result of evolution isfitness and variety of species, then the material for it are mutations and combinative variability within the genome. It is the mutations that cause the appearance of new signs that creatively assess the natural selection for suitability and necessity in the specific habitat of the species. Genetic variability and fluctuations in the numbers of individuals in populations (population or life waves) provide material for incorporating mechanisms for the struggle for survival and survival of the fittest.

Creative directions

The struggle for existence as a consequencenatural selection leads to the fact that the result of evolution is the emergence of new species from the ancestors. And natural selection can go in three directions:

• Driving - occurs with changes in the environment, and then the result of evolution is the shift in the mean values ​​of the characteristic toward its increase or decrease.
• Stabilization - this way will goevolution of the species under unchanged environmental conditions. With this type of selection, the optimal norm is maintained, and all extreme manifestations of the trait are eliminated from the population.
• The tearing off of the population begins with sharpchanges in the environment. Then most of the population with signs in the norm dies dramatically, and the carriers of the extreme characteristics of the trait are the most adapted to the changed conditions.

Genetic or reproductive isolation

Whichever way evolution goes, the main thingthe condition for the formation of new species is reproductive isolation - the impossibility of a free crossing of individuals for panmictic species (reproductive by sex). It is worth saying that the achievement of reproductive isolation in nature proceeds in two ways: allopatric (reproductive isolation is achieved by geographic division of populations) and sympatric (isolation occurs in a single area with a maternal view). In any case, as soon as a regime of impossibility of free crossing is established between populations, one can say that the result of the evolution of the organic world is the formation of a new species, and this process is completed.

Examples of successful animal fitness

Once the changes in the characteristic appear in thegenome, they are tested by natural selection. The most successful are fixed morphologically and become adaptive. There are many examples in nature. Successful morphological adaptations include patronizing and warning coloring, means of camouflage and passive protection. Patronizing coloration, for example, white plumage in a partridge in winter, makes the animals invisible against the background of the surrounding environment. Preventive coloring is possessed by those organisms that have in their arsenal chemical means of protection from enemies. For example, the red-black color of poisonous frogs-drevolazov or yellow-black in poisonous salamanders. Masking as a defense against enemies can be truly passive (the shape of a stick's body really resembles a wand) or imitative (for example, the belly of a butterfly-glazer is very similar to the abdomen of wasps, so the birds do not touch it).

Relativity of evolutionary fitness

All evolutionary scientists agree with the statement,that the nature of fitness is relative. There are absolutely no useful signs, as there are absolutely useless ones. All adaptations are developed in specific environmental conditions and when they change, they may be useless or even harmful. Protection from one enemy can be useless when protecting from another (stinging wasps and hornets are not eaten by most birds, but flycatchers and chickens eat mostly by them). Behavioral features may be meaningless (for example, a maternal instinct that causes the starling to rear the cuckoo). A useful organ or skill in other conditions becomes a burden (for example, the flying fish jumps out of the water and escapes from water predators, but becomes the prey of the albatross).

Summarizing

About 7.5 million species of animals, about 300thousands of plant species and 600 species of mushrooms, add 36 thousand species of unicellular organisms - all this diversity is the main result of the evolution of life on planet Earth. And they are perfectly adapted to their living conditions. For 3.7 million years of life on the planet, living organisms have constantly evolved and adapted to environmental conditions, and this process continues today.