B1.8: Evolution

Early Ideas



  1. A giraffe stretches its neck to reach the food high up
  2. The giraffes neck gets longer because it stretches every time it eats
  3. The giraffe passes this characteristic onto its offspring
  4. The giraffe’s offspring inherit its long neck

Charles Darwin


  1. There are lots of giraffes with different length necks
  2. The giraffes with the longer necks can reach food high up a tree
  3. The giraffes with the longer necks can get more food to survive and reproduce
  4. They outcompete giraffes with shorter necks
  5. Their offspring inherit the genes for longer necks

Opposition to Darwin’s Theory

Natural Selection Model Answer

  1. There is genetic variation within a population
  2. If the environment changes certain characteristics may become more favourable than others
  3. The organisms which are better adapted are able to outcompete other individuals and survive
  4. The well adapted organisms are able to survive longer and reproduce more
  5. Their offspring inherit the advantageous genes and characteristics
  6. The population changes as the characteristics become more frequent



  1. Kingdom
    1. Animalia - Animals
    2. Fungi - Fungus
    3. Plantae - Plants
    4. Prokaryotae - Bacteria
    5. Protoctista – Single celled organisms
  2. Phylum
  1. Order
  2. Family
  3. Species
    1. A group of organisms which are able to successfully reproduce with each other