Artificial Selection

• Animal and Plant Breeding

  • artificial selection (selective breeding): the intentional breeding/reproduction of individuals with desirable traits, resulting in changes in allele frequency in gene pools over time
  • traits are beneficial for humans
  • specific allele frequencies will decrease and variation will decrease as humans breed for specific desirable traits
• Example: Sheep and Cattle

  • selected characteristics include quality and quantity of meat, quality of wool, and size of sheep
  • the Belgian Blue is a breed of cattle that's been bred for the meat industry through artificial selection - they have huge muscles as a result of unregulated muscle development due to a naturally occurring "double muscling" mutation
• Example: Fruits and Vegetables

  • improved quality - increase nutrition and flavour
  • increase yield
  • longer storage period
  • higher tolerance to insect pests and herbicides
• Similarities Between Natural and Artificial Selection

  • traits inherited from parents
  • change in allele frequency
  • change occurs over many generations
• Differences Between Natural and Artificial Selection

  • natural occurs naturally w/o human interference - humans select desired traits that benefit humans
  • natural increases species' chance of survival, artificial may not enhance survival of species
  • natural has a slower growth rate and therefore has time to adapt to changes in the environment - artificial usually has a faster growth rate
  • higher genetic variation in natural and less susceptible to changes in the environment - artificial increases nutritional value, yield, pest resistance, drought resistance, and disease resistance