artificial selection

• A selection pressure is an external factor that increases or decreases the survival and/or reproductive success of an organism
• Artificial selection follows the same process as evolution and speciation except the selection pressure is one applied by humans with a particular goal in mind.
• Wild type: The original “naturally occurring” organism. This produces the most common phenotype.
• Mutant: When an allele is changed, altering the base sequence and producing variation in the phenotype.
• The process of artificial selection

  1. A desirable trait or characteristic is selected.
  2. Two individuals that have these traits are bred together.
  3. The offspring that are produced are selected again for the same trait.
  4. The process is repeated over many generations to enhance the trait in the population.
• Problems with artificial selection

  • Artificial selection reduces the gene pool and reduces genetic variation.
  • By selecting just a few alleles you limit the outbreeding and encourage inbreeding.
  • This can lead to genetic disorders.
  • It also leads to a lack of genetic variation in the gene pool meaning organisms are more vulnerable to disease.