Artificial Selection :
Artificial Selection ARTFICIAL SELECTION is the evolution of crops and animals for the sole benefit of man.
It can be achieved by hybridisation and inbreeding. Speed strength
Inbreeding :
Inbreeding INBREEDING is the breeding together of species from the same strains through many generations.
It has negative effects through inbred lines It gives little genetic diversity which means that the species can not evolve to changing conditions
There are an increased chance of the organism obtaining harmful recessive alleles which give more hereditary diseases.
Hybridisation :
Hybridisation HYBRIDISATION is the interbreeding of genetically different varieties. The offspring produced are often said to have hybrid vigour as they are genetically superior to their parents, this is because the recessive alleles are masked. It is useful in the farming of crop plants as the F1 hybrids are:
Are all the same, producing a uniform crop.
Have a higher yield.
Are often sterile so are seedless.
Extinction of Species :
Extinction of Species Species that have become endangered show a loss of genetic diversity, due to:
A decreasing population size.
Inbreeding occurring. Species may become extinct due to
Habitat destruction
Overhunting
Conservation of Species :
Conservation of Species CONSERVATION maintains the genetic diversity of a species this;
Ensures species survive.
Provides a source for selective breeding. Types of conservation:
Wildlife Reserve- preserve a animals habitat
Captive Breeding- increases numbers
Cell banks- storage of genetic material