Artificial Selection (Cambridge International IGCSE Science)

Selective Breeding

• Selective breeding, also known as artificial selection involves the following process

  • Selection by humans of individuals with desirable characteristics
  • Crossing the individuals with desirable characteristics together
  • Choosing offspring from the cross which also show the desirable characteristics and breeding them together
  • Repetition of this process over many generations

• Selective breeding over many generations eventually results in crop and domestic animal varieties which all show characteristics chosen by humans, e.g.

  • Dog breeds with calm and friendly temperaments and attractive visible traits
  • Crop varieties that are resistant to pests and that produce a high yield

Selective breeding in dogs diagram

Selective breeding in dogs has given rise to a wide variety of domestic breeds that are all descended from wild wolf ancestors

Selective breeding in crops diagram

Selective breeding in plants has resulted in a wide range of closely related crop varieties

Exam Hint You could be asked to apply the principles of selective breeding to unfamiliar examples in an exam, so make sure that you have a good understanding of the steps involved:

• Humans select individuals with desired characteristics
• Individuals are bred together
• Offspring with desired characteristics are chosen
• Repeat over many generations