Allele Frequency

ninja icon


•  Individuals that are better adapted tend to survive and produce more offspring while the less well adapted tend

    to die or produce fewer offspring

The variation that exists within a population is heritable (i.e. genetic) and determined by the presence of alleles

  • These alleles may be passed from parent to offspring via sexual reproduction

Alleles encode for the phenotypic polymorphisms of a particular trait and may be beneficial, detrimental or neutral:

  • Beneficial alleles will better equip the organism to survive and hence produce more offspring (encodes beneficial adaptations)
  • Detrimental alleles will harm the survival prospects of an organism, leading to fewer viable offspring
  • Neutral alleles will not affect the organisms survival prospects

Due to natural selection, the proportion of different alleles will change across generations (evolution)

  • As beneficial alleles improve reproductive prospects (more offspring), they are more likely to be passed on to future generations
  • Conversely, detrimental alleles result in fewer offspring and hence are less likely to be present in future generations

If environmental conditions change, what constitutes a beneficial or detrimental trait may change, and thus the allele frequencies in a population are constantly evolving

Changing Allele Frequencies (Evolution)

allele evolution