The founder of the concept of "selection" is Charles Darwin, who was able to describe the role of hereditary variability and artificial selection in the creation and breeding of new breeds and varieties.
What is selection
The definition is formulated as follows: "Breeding is the science that studies the methods of creating and improving varieties of cultivated plants, breeds of domestic animals and strains of microorganisms."
A variety or breed is a population created by man under artificial conditions that has invaluable benefits for humans: it has useful hereditary traits, high productivity, and the necessary physiological and morphological parameters.
Selection (what does it mean - studies biology in detail) is characterized by the appearance of breeds of domestic animals, as well as new varieties of cultivated plants resulting from artificial selection, which can only be carried out by humans.
Cultural forms are characterized by the fact that they have very strongly developed certain features with which it is difficult for the body to exist in its natural environment, but they are useful for humans. A prime example is the possibility of a chickengive three hundred eggs a year. In nature, such a feature of the bird is meaningless, since the chicken will not be able to hatch three hundred eggs.
Historical facts
At the beginning of its existence, selection was a method of artificial selection. What is painstaking long-term work aimed at obtaining a certain useful trait - only the breeders themselves know. Until the seventeenth century selective selection was unconscious. For example, a person chose the largest seeds to get a good harvest, without thinking that the plant is already changing in the direction that the person needs.
And only about a hundred of the last years, a man began, not yet studying the principles and laws of genetics, to purposefully and consciously cross such plants that maximally satisfy human desires and needs.
But man could not create new types of living organisms only by the method of artificial selection. Using this method, it is possible to isolate only those genotypes that already exist in the population. That is why hybridization is currently being used to produce completely new plant varieties and animal breeds.
What is plant breeding
The most important methods of plant breeding are hybridization and selection. For cross-pollinated plants, mass selection of the desired properties is used. Otherwise, it is impossible to obtain the material necessary for further work. Thanks to this method, it is possible to obtain new varieties of cross-pollinated plants (for example, rye). Such varieties are notwill be genetically identical. But to obtain a pure line, scientists use individual selection, during which, as a result of self-pollination, one can obtain high-quality specimens with the necessary characteristics and characteristics.
Experimental polyploidy is very often used for plant breeding, as each polyploid is characterized by high yield, large size and relatively fast growth.
There is also a method of artificial mutagenesis, which was considered by Vavilov. An organism that succumbed to mutation and acquired new properties is called a mutant, and the process of transformation itself is called a mutation.
Features of animal breeding
What is animal breeding is not difficult to answer. It is very similar to plant breeding, but still has some features. It should be borne in mind that only sexual reproduction is characteristic of animals. Due to the very rare change of generations (in many animals after several years), the number of individuals in the offspring is extremely small. That is why, when conducting breeding work, scientists must analyze all the external features characteristic of a particular breed.
Domestication
What is selection in biology? The definition is given in the school curriculum. The most important human achievement was the domestication of wild animals over ten thousand years ago. Thus, people have a constant source of food.
It is common for pets to havespecial signs, which are very often harmful to natural existence, but for a person they have an invaluable positive value. The domestication factor is the artificial selection of individuals that meet human requirements. People chose animals that had a good appearance, a calmer disposition, and other qualities that were important to humans.
After the unconscious came methodical selection. Its goal is to form the necessary and useful qualities in animals.
The method of domestication of new animals is practiced by man even now. He needs this, for example, to obtain high-quality furs. Thus, a new branch of the economy appeared - fur farming.
Crossing and selection
Selection (what it means for humanity - you can find out by reading this article) also considers such a method as animal crossing. This is done to improve the appearance, quality of meat or increase the fat content of milk. Individuals that are bred are judged not only by their appearance, but also by the quality of their offspring. That is why it is very important to study their pedigree.
Currently there are two types of crossbreeding: outbreeding and inbreeding. The first type is characterized by crossing individuals not only of one, but also of different breeds. Further rigorous selection is able to maintain useful qualities and increase their number in offspring.
During inbreeding, parents and offspring, or brothers and sisters, are used. Thanks to this crossing, homozygosity increases and valuabletraits in offspring.
Distant hybridization has a relatively low effect, because interspecific hybrids of animals are most often sterile.
What is the selection of standardization objects? This concept characterizes the activity, which consists in the selection of certain objects recognized as suitable for their further production, and application in all spheres of human life.
Microorganism selection
Microorganisms play a very important role in the biosphere, and directly in human life. Humanity uses several hundred microorganisms, and their number is growing every year.
The selection of microorganisms is characterized by a number of features. Breeders have an infinite amount of material in stock. Since the gene of any microorganism is haploid, scientists can detect a mutation as early as the first generation. Bacteria have a relatively small number of genes, so the work is much easier and faster.
Bacteria can independently produce substances useful to humans, and this property is used by microbial selection. What is the method of genetic engineering in this industry? This is a combination of influences that provokes bacteria to produce compounds that are not produced naturally.
Sometimes breeders use transduction - they transfer the necessary DNA from one bacterium to another and thus increase the importance of microorganisms for the environment.
An important method of breeding work with microorganisms is hybridizationdifferent strains. This method allows you to combine materials that cannot be found in nature.
How breeding work is being done
What is selection in biology? The definition allows you to learn about new improved varieties, strains and populations of living organisms. To date, all breeding work is carried out taking into account what the agricultural market and production need. For example, scientists have developed a unique technology for the utilization of petroleum products, with the ability to turn them into a protein-vitamin useful product. Such an achievement arose due to the selection of bacterial strains.
What is selection in biology? A very important area of applied science, which allows a person to get high-quality food and new types of modern production.
