Variation and Evolution

• What can lead to huge variation between individuals?

  Differences in genes and environment
• What is the term used in biology to describe differences among individuals?

  Variation
• What describes the observable characteristics of an individual?

  Phenotype
• What two factors determine a phenotype?

  Genes and environment
• What do genes code for?

  Proteins
• What is a genome?

  All of an individual's genes combined
• Who has a unique genome apart from identical twins?

  Everyone in the world
• How can identical twins differ in height?

  Due to differences in diet and sleep
• What can affect the skin color of identical twins?

  Time spent in the sun
• What determines most of our characteristics?

  Interaction of genes and environment
• What causes genetic variation?

  Mutations
• What is a mutation?

  A change in the DNA code
• What is the effect of most mutations on phenotypes?

  They don't change the phenotype
• What can beneficial mutations do?

  Make individuals more resistant to diseases
• What did Charles Darwin notice about certain traits?

  They were passed on from parent to child
• What term did Darwin use to describe the survival of the fittest?

  Natural selection
• What does evolution describe according to Darwin?

  Inheritance of characteristics over generations
• What does the theory of evolution imply about all living species?

  They evolved from simple life forms
• What evidence supports Darwin's theory of evolution?

  Development of antibiotic resistance in bacteria
• What happens to phenotypes of two populations over time?

  They may become so different they can't interbreed
• What is the process of evolution through natural selection?

  • Variation in traits among individuals
  • Genetic mutations lead to different phenotypes
  • Beneficial traits enhance survival and reproduction
  • Over generations, these traits become more common
  • New species may form when populations diverge
• What are the key concepts of Darwin's theory of evolution?

  • Natural selection: survival of the fittest
  • Inheritance of traits from parents
  • Evolution occurs over multiple generations
  • All species have evolved from earlier forms