Mutation (MFE)

• Mutation

  • the source of new alleles in a populations gene pool
  • a permanent change in the DNA sequence of a gene
  • can change 1 allele to another, but the net effect is a change in the frequency of an existing allele
  • change in allele frequency is small, so mutations' effect on evolution is insignificant unless it provides a beneficial trait
• Ultimate Source of Variation

  • members of a population have variation in their genotypes which cause variation in their phenotypes
  • variation is based on differences in DNA sequence, which result in different forms of alleles, which in turn result in different phenotypes
• Gene Pool

  The total collection of alleles within a population
• Selection Pressure (definition/general)

  • an environmental factor that can be survived by individuals who possess beneficial/advantageous traits, but not by others
  • can contribute to change in allele frequency in a gene pool
  • a mutation may produce an allele that's selected for, against, or selectively neutral
• Selection Pressures (examples)

  • resources - presence of food, shelter, prey
  • abiotic factors - temperature, water availability, pH
  • biotic factors - pathogens, diseases, predators