Variation and evolution

• Why is there variation?

  Each individual has different phenotypes
• What is a phenotype?

  observable characteristic of an individual due to their genes and environment
• Who do genes code for?


  Proteins
• What does the genome code for ?

  entire organism
• What does it mean to have unique genomes?

  they have slightly different combinations of proteins inside them so they look different
• What people don't have unique genomes?

  Identical twins
• What are most of our characteristics determined by?

  The interaction of our genes and our environment
• Why is there genetic variation?

  Mutation
• What is mutation?


  change in the DNA code so the protein that it codes for may be different so the phenotype will charge slightly

  
  

  They are usually something bad but are occasionally beneficial
• Do most mutations have an effect?

  No, they don't have an effect in proteins so don't change the organisms phenotype
• What are examples of beneficial mutations?

  resistant to lung disease and ability to run faster
• What does beneficial mutations mean for those individuals who have them?

  those individuals are more likely to survive so more likely to reproduce and pass on their genes to the next generation

  
  

  Darwin called this survival of the fittest
• How did Darwin discover natural selection?

  Darwin didn't know about mutations but noticed that traits were being passed on from parent to child and that the most useful traits were passed on the most
• What is evolution?

  A change in the inherited characteristics of a population over time through a process of natural selection which may result in the formation of a new species.
• What does the theory of evolution by natural selection imply?

  that all living species must have evolved from the simple life forms that first developed more than 3billion years ago
• Why is Darwin's theory now accepted?

  due to the development of antibiotic resistance in bacteria or looking at fossil records
• How does evolution occur?

  through the natural selection of genetic changes that give rise to the phenotypes that are best suited to the environment
• What happens if two populations of one species become so different in phenotype?

  they can no longer interbreed to produce fertile offspring so at that point we can say a new species has formed