selective breeding

• Selective breeding


  Taking the best plants or animals in a population and breeding them together to get even better offspring
• Humans have been using selective breeding for thousands of years, ever since the start of agriculture
• Things selectively bred for

  • Cows that produce lots of meat or milk
  • Crops resistant to diseases
  • Friendly cats and dogs
  • Plants with large or unusual flowers
• How selective breeding works

  Look at the individuals in the existing stock

  2. Select the ones with the desired characteristics

  3. Breed the selected ones together

  4. Repeat, always picking the best from each generation
• Selective breeding can lead to dramatic changes, like the difference between modern sweet corn and its original wild form
• Drawbacks of selective breeding

  • Reduces the gene pool of the population

  Inbreeding can lead to health issues in offspring

  Lack of genetic variation makes the population vulnerable to new pathogens
• Selective breeding involves selecting for certain alleles that code for the desired traits, reducing the overall gene pool
• Breeding the best individuals, who are often closely related, can lead to inbreeding and inherited defects
• A small gene pool means less variation, so a new pathogen could potentially affect the entire population