variation & evolution

• Variation

  Differences between individuals in a population
• Phenotype

  Observable characteristics of an individual due to the interaction of genes and environment
• Genes

  Code for proteins and the genome, which is all of an individual's genes combined
• Except for identical twins, everyone has a unique genome</b>
• Environment

  Factors outside the individual that can influence their phenotype
• Most characteristics are determined by the interaction of genes and environment
• Mutation

  A change in the DNA code that may change the protein it codes for
• Most mutations don't affect the phenotype
• Beneficial mutations

  • Make individuals more resistant to disease or able to run faster
  • Increase the likelihood of survival and reproduction
• Natural selection

  The process where fitter individuals are more likely to survive and reproduce, passing on their beneficial traits
• Evolution

  The change in the characteristics of a species over multiple generations, leading to the development of new species
• All current species have evolved from simple life forms that developed over 3 billion years ago
• Evolution by natural selection has been proven multiple times, such as through antibiotic resistance in bacteria and the fossil record