Natural Selection

Natural selection is the ability of an organism to survive to reproduce in their environment based on their genetic makeup. Some alleles will give the organism a higher probability of survival than others. Superior traits that aid the organism in its struggle to survive are often referred to as adaptations. There are five main forms of selection:

• Stabilizing selection eliminates individuals with extreme or unusual traits.
  
  
• Directional selection favors traits at one extreme of the range of traits.
  
  
• Disruptive selection occurs when the environment favors extreme traits over common traits.
  
  
• Sexual selection is the selection of a mate based on a trait. In male competition the male that wins the contests of strength, agility, etc. mates with the female. In female choice the female mates with the male that she prefers based on certain characteristics.
  
  
• Artificial selection is a form of selection carried out by humans.