Describe the forms of artificial selection. What are the similarities and differences between them?

Darwin identified two forms of artificial selection – unconscious and methodical. With unconscious selection, a person does not set himself the goal of creating a new breed or variety, but by multiplying some individuals and removing others, he slowly changes the attributes of organisms that are useful to themselves. Methodological selection – the targeted removal of animal species or plant varieties by a person. In this case, the breeder draws attention to the characteristics that are most desirable for him in specific conditions, and subsequently constructs a breed or variety. Based on the hereditary variability of organisms, a person selects pairs for crossing, ensures maximum development and consolidation of the desired traits from generation to generation.

The main forms of artificial selection
1. Unconscious selection, the oldest, does not set a specific goal for breeding new breeds of animals or plant varieties, but selects the best individuals.
2. Methodological selection is more progressive, because provides for specific goals, sets specific tasks in the breeding of new breeds and varieties.
3. Inbreeding is a closely related selective crossing in order to preserve and spread especially desirable traits. Inbreeding is often used in breeding cats and dogs. .
4. Outbreeding is not a crossbreeding of genetically diverse populations. Outbreeding is used to obtain new, more valuable traits in plants.
5. Unintentional selection – selection when resistance to antibiotics, herbicides and pesticides occurs.

Comparison of artificial and natural selection

Indicators Artificial selection Natural selection
Source material for selection Individual signs of the body Individual signs of the body

hereditary mutation variability

Selection factor Person Environmental conditions
The path to favorable change Selected, useful traits become productive. Remain, accumulate, inherited
The path of adverse change Selected, rejected, destroyed Destroyed in the struggle for existence
Nature of action Creative – directed accumulation of signs for the benefit of man Creative – selection of adaptive traits for the benefit of an individual, population, species, leading to the emergence of new forms
Selection result New plant varieties, animal breeds, microorganism strains New species

Evolution (change, complication of organisms)

The adaptability of organisms to environmental conditions

There cannot be cultivated plants equally productive in any locality. Under the influence of natural selection zoning of varieties occurs

Selection forms Massive, individual, unconscious, methodical Driving, stabilizing, destabilizing, disruptive, sexual
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