TYPES OF SELECTION

• WHAT ARE THE TYPES OF SELECTION?

  directional, stabilising
• DIRECTIONAL SELECTION?

  • one of the extremes has a selective advantage
  • occurs when there is a change in the environment
  • modal trait changes
  • e.g. antibiotic resistance in bacteria
• STABILISING SELECTION?

  • modal trait has selective advantage
  • occurs when there is no change in the environment
  • modal trait remains the same
  • standard deviation decreases (individuals with extreme trait decrease)
  • e.g. human birth weight