darwin’s theory

• Genetic variation occurs because the genetic information of an organism is a mixture of the parent’s DNA.
• All individuals in a species show a variety of particular characteristics suiting the environment that help them survive.
• Natural selection:

  1. Selection pressures (competition, diseases, predators) exist.
  2. Random mutation gives some individuals a selective advantage and they are better adapted to the environment.
  3. Organism survives and reproduces, passing on beneficial alleles.
  4. Frequency of advantageous alleles in organisms increase.