KA 6: Evolution of Species

• What is a mutation?

  A random change to genetic material.
• What are the possible effects of mutations on survival?

  Mutations may be neutral, confer an advantage, or a disadvantage to survival.
• What is the source of new alleles?

  Mutations are the only source of new alleles.
• How can environmental factors affect mutation rates?

  Environmental factors, such as radiation and some chemicals, can increase the rate of mutation.
• How do new alleles produced by mutation affect adaptation?

  New alleles can result in plants and animals becoming better adapted to their environment.
• What role does variation within a population play in evolution?

  Variation within a population makes it possible for a population to evolve over time in response to changing environmental conditions.
• Why do species produce more offspring than the environment can sustain?

  Species produce more offspring than the environment can sustain due to natural selection or survival of the fittest.
• What occurs when there are selection pressures in a population?

  Natural selection or survival of the fittest occurs when there are selection pressures.
• What happens to the best adapted individuals in a population?

  The best adapted individuals in a population survive to reproduce, passing on the favourable alleles that confer the selective advantage.
• What happens to the frequency of favourable alleles in a population?

  Favourable alleles increase in frequency within the population.
• What is speciation?

  Speciation occurs after part of a population becomes isolated by an isolation barrier.
• What types of isolation barriers can lead to speciation?

  Isolation barriers can be geographical, ecological, or behavioural.
• What happens to mutations in isolated sub-populations?

  Different mutations occur in each sub-population.
• How does natural selection affect different sub-populations?

  Natural selection selects for different mutations in each group due to different selection pressures.
• What is the outcome of different mutations and selection pressures in isolated sub-populations?

  Each sub-population evolves until they become so genetically different that they are two different species.
• Speciation occurs after part of a population

  becomes isolated by an isolation barrier,

  which can be geographical, ecological or

  behavioural. Different mutations occur in

  each sub-population. Natural selection

  selects for different mutations in each group,

  due to different selection pressures. Each

  sub-population evolves until they become so

  genetically different that they are two

  different species.
• What is a mutation?


  A mutation is a random change to genetic material.
• What are the possible effects of mutations on survival?

  Mutations may be neutral, confer an advantage, or a disadvantage to survival.
• What is the source of new alleles?

  Mutations are the only source of new alleles.
• How can environmental factors affect mutation rates?

  Environmental factors, such as radiation and some chemicals, can increase the rate of mutation.
• How do new alleles produced by mutation affect adaptation?


  New alleles can result in plants and animals becoming better adapted to their environment.
• What role does variation within a population play in evolution?

  Variation within a population makes it possible for a population to evolve over time in response to changing environmental conditions.
• Why do species produce more offspring than the environment can sustain?

  Species produce more offspring than the environment can sustain due to natural selection or survival of the fittest.
• What occurs during natural selection?

  Natural selection occurs when there are selection pressures, and the best adapted individuals survive to reproduce.
• What happens to favorable alleles during natural selection?

  Favorable alleles that confer a selective advantage increase in frequency within the population.
• What is an adaptation?

  An adaptation is an inherited characteristic that makes an organism well suited to survival in its environment/niche.
• What triggers speciation?

  Speciation occurs after part of a population becomes isolated by an isolation barrier.
• What types of isolation barriers can lead to speciation?

  Isolation barriers can be geographical, ecological, or behavioral.
• What happens to mutations in isolated sub-populations?


  Different mutations occur in each sub-population, and natural selection selects for different mutations due to different selection pressures.
• How does evolution occur in isolated sub-populations?

  Each sub-population evolves until they become so genetically different that they are two different species.
• What is a mutation?

  A mutation is a random change to genetic material.
• What are the possible effects of mutations?

  Mutations may be neutral, advantageous, or disadvantageous.
• What is the source of new versions of genes (alleles)?

  Mutations are the only source of new versions of genes (alleles).
• What environmental factors can increase the rate of mutations?

  Radiation, high temperatures, and some chemicals can increase the rate of mutations.
• How do new alleles produced by mutation benefit plants and animals?

  They allow plants and animals to adapt to their environment.
• What types of adaptations can result from mutations?

  • Structural adaptations
  • Behavioral adaptations
• How does variation caused by mutation affect a population?

  Variation within a population makes it possible for the population to evolve over time in response to changing environmental conditions.
• What triggers natural selection?


  Natural selection occurs when more offspring are produced than the environment can sustain.
• What happens to the best adapted individuals in natural selection?


  Only the best adapted individuals survive and reproduce, passing on their advantageous genes.
• What is a good example of natural selection in action?

  The change in the peppered moth population since the 1850s is a good example.