Aquatic ecology and Biodiversity

Unit 8- Animal associations and interactions

8.13. Artificial selection

When the population is fished, many of the largest fish are removed, so, more of the small-bodied fish remain.
Artificial selection is the intentional selection, breeding of plants or animals. It means the selective breeding.
Selective breeding is a technique used to breed domesticated animals, such as fishes, dogs, pigeons or cattle etc. Some of these animals will have traits that a breeder want to preserve. The breeder therefore, select those animals to breed that have such a good quality. Selective breeding often leads to inbreeding and loss of fertility. To control this, most breeds are outcrossed or backcrossed to wild-type individuals or at least less inbred stock. Charles Darwin used the example of artificial selection to introduce his idea of natural selection. Artificial selection may be contrasted with the process of natural selection. In natural selection, the differential reproduction of organisms with certain traits happens. This is because some variations help the organism to have better survival and reproduction and also maintains or enhances the fitness of a population in its natural habitat.
Artificial selection may sometimes be unintentional; it was thought that domestication of crops or animals by early humans was largely unintentional. Inbreeding is a particular kind of selective breeding, designed to produce a population which is genetically, virtually identical. Such populations are rarely viable outside the laboratory. Sometimes a dwindling population needs a jumpstart. And for threatened or endangered fish populations, that often means supplementing wild populations with hatchery-raised fish. But this conservation tactic is not risk-free: hatchery fish populations may evolve in different directions from wild populations—and hatchery genes may be dangerous for wild populations