artificial selection

Biologist

2022

We explain what artificial selection or selective breeding is, its types, advantages, disadvantages and examples. Also, natural selection.

Artificial selection occurs for productive, aesthetic, or convenience reasons.

What is artificial selection?

In biology, is called artificial selection or selective breeding to the different ways in which the human being intervenes in the evolution of various species animals and plants, choosing according to productive, aesthetic or convenience criteria, which should be the favored traits in the genome of a species and which not.

It is a process of conduction of evolution parallel and different from natural selection (the latter occurs without human interference).

Selective breeding has been implemented by humans since the first animal and plant species were subjected to domestication, thus forever altering their evolutionary destinies, at the convenience of their relationship with our species.

Through the selection of parents, interbreeding and inbreeding, human beings have directly influenced the frequency of appearance of certain inherited traits in these life forms, distinguishing between different races (in the case of animals) and varieties (in the case of vegetables Y mushrooms).

For this reason, domestic animals They have an evolutionary path different from that of their wild relatives, since their closeness to humans and their way of life has taken them away from the influence of natural competition and the survival of the fittest.

Types of artificial selection

Positive selection seeks the reproduction of individuals with desired traits.

Depending on the degree of planning involved by the human being, artificial selection can be:

  • Aware. When it responds to a selection plan, designed and executed at will, to preserve certain traits above others in a domestic species.
  • Unconscious. When it happens accidentally, responding to criteria not planned in advance or at least not formalized.

Similarly, one can differentiate between artificial selection that encourages reproduction of individuals with desired traits (positive artificial selection), and that which prevents the reproduction of individuals with unwanted traits (negative artificial selection).

Advantages of artificial selection

The selected traits respond to human preferences.

Artificial selection allows the most harmonious or close coexistence between the humanity and domestic species, since the dominant traits in the latter respond to human interests, needs or preferences.

This means that human needs are met, and that in return the domesticated species is guaranteed its survival, often on much more comfortable terms than in its original wild environment: an established home, constant food, absence of predators.

Disadvantages of artificial selection

Crowded animals like salmon suffer from disease.

Not always the living conditions with humanity are so favorable for the domesticated species. Among the possible disadvantages that selective breeding brings with it is the weakening of the species: farm animals, overcrowded and in poor conditions of HealthThey are susceptible to diseases and defects that they would not have in their wild environment.

On the other hand, artificial selection, by obeying the reasons of the human being and not those of the species, usually brings with it evolutionary problems for the species, such as diseases, anatomical difficulties, mutations unpredictable, etc.

Also, in case domestic species need to return to their habitat wild, they will be far worse adapted than any other to survive.

Examples of artificial selection

All crops go through an artificial selection of desired characteristics.

Some examples of artificial selection are:

  • The upbringing of the different breeds of domestic dog, greatly distinguishing between companion animals (generally small) and guard or fighting animals (generally large).
  • The extinction of some violent or dangerous breeds of dogs or cats, through the control or reduction of their reproduction.
  • The abnormally large reproduction of salmon and other fish species farmed in fish farms, and alongside them of new diseases resulting from overcrowding or lack of natural competition.
  • The different forms of genetic improvement of corn, wheat and other domestic plant species, thus increasing the nutrients of their fruits or the size of their respective productions.

Natural selection

Natural selection occurs in the wild without human intervention.

Contrary to artificial selection, natural selection is the process of adaptation of species in their wild habitat, according not to the will of anyone but to the specific needs of the species and the demands of its environment.

Natural selection is the main engine of evolution and the creation of species. It occurs from the survival of the fittest, within the eternal struggle for reproduction that constitutes, in essence, the life.

!-- GDPR -->