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 a science that studies the methods of creating and improving cultivars , domestic animal breeds and microorganism strains."
A variety or breed is a population created by a person in artificial conditions, which has invaluable benefits for a person: it has useful hereditary traits, high productivity, and the necessary physiological and morphological parameters.
Breeding (what it means - biology studies in detail) is characterized by the appearance of domestic animal breeds, as well as new varieties of cultivated plants resulting from artificial selection that can only be done by humans.
Cultural forms are characterized by the fact that they have very strongly developed certain signs with which the body is difficult to exist in the natural environment, but for humans they are useful. A striking example is the ability of a chicken to give three hundred eggs per year. In nature, this 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 an artificial selection method. What is painstaking long-term work aimed at obtaining a certain useful attribute - only breeders themselves know. Until the seventeenth century, selection was unconscious. For example, a person chose the largest seeds to get a good harvest, without thinking that the plant was already changing in the direction that the person needed.
And only about the last hundred years, a person began, not yet studying the principles and laws of genetics, purposefully and deliberately interbreeding plants that satisfy human desires and needs as much as possible.
But only by artificial selection, man could not create new types of living organisms. 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, which makes it possible to obtain completely new plant varieties and animal breeds.
What is plant breeding?
The most important plant breeding methods 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, new varieties of cross-pollinated plants (e.g. rye) can be obtained. Such varieties will not be genetically homogeneous. But to obtain a clean line, scientists apply individual selection, during which, as a result of self-pollination, one can obtain high-quality specimens with the necessary characteristics and signs.
Experimental polyploidy is very often used for plant breeding, since each polyploid is characterized by high productivity, large size, and relatively rapid growth.
There is also a method of artificial mutagenesis, which was considered by Vavilov. An organism that succumbs to a mutation and receives 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 generational change (in many animals after several years), the number of individuals in the offspring is extremely small. That is why, when conducting breeding work, scientists should analyze all the external characteristics characteristic of a particular breed.
Domestication
What is selection in biology? Definition is given in the school curriculum. The most important achievement of mankind was the domestication of wild animals more than ten thousand years ago. Thus, people have a constant source of food.
Pets are characterized by the presence of special features, which are often harmful to natural existence, but for humans they are 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 more relaxed character and other qualities important to humans.
After the unconscious, methodical selection appeared. Its purpose is to form the necessary and useful qualities in animals.
The method of domestication of new animals is practiced by man today. He needs this, for example, to obtain high-quality fur. Thus, a new branch of the economy appeared - fur farming.
Crossbreeding and selection
Breeding (what it means to humanity - you can find out by reading this article) also considers a method such as crossing animals. This is done to improve the appearance, quality of meat or increase the fat content of milk. Individuals that are bred are evaluated not only by their appearance, but also by the quality of their offspring. That is why it is very important to study their pedigree.
At the moment, there are two types of crosses: outbreeding and inbreeding. The first type is characterized by the crossing of individuals of not only one, but also of different breeds. Further rigorous selection is able to maintain beneficial qualities and increase their number in the offspring.
During inbreeding, parents and offspring, or brothers and sisters, are used. Thanks to this crossing, homozygosity increases and valuable traits in the offspring are fixed.
Remote hybridization has a relatively low effect, because interspecific hybrids of animals are most often infertile.
What is 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 areas 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 in the first generation. Bacteria have a relatively small number of genes, and therefore work is much easier and faster.
Bacteria can independently produce substances useful to humans, and this property uses microorganisms selection. What is the genetic engineering method in this industry? This is a set of effects that provokes bacteria to produce compounds that are not produced in vivo.
Sometimes breeders use transduction - they transfer the necessary DNA from one bacterium to another and thus increase the importance of microorganisms to the environment.
An important method of breeding work with microorganisms is the hybridization of different strains. This method allows you to combine materials that can not be found in nature.
How are breeding works
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 being carried out taking into account what the agricultural market and production need. For example, scientists have developed a unique technology for the disposal of petroleum products, with the ability to turn them into a protein-vitamin useful product. This achievement arose thanks to the selection of bacterial strains.
What is selection in biology? A very important area of applied science, which allows a person to receive high-quality food products and new types of modern production.