speciation

• Speciation


  The process that results in creation of new species
• Speciation


  1. Original population splits

  2. Over many generations becomes two different species

  3. Cannot breed together with original species to make fertile offspring (reproductively isolated)
• Allopatric speciation


  • Population can become separated/reproductively isolated geographically
  • Unable to reproduce due to geographical barrier
  • Within the two populations, there are always random mutations
  • Over time both populations acquire different beneficial mutations to help their survival in different environments
  • Differences in DNA mean over time they become genetically different
• Sympatric speciation


  • Population can become reproductively isolated due to behavioural differences
  • Geographically not separated in same location but unable to reproduce
  • Due to random mutation that impacts reproductive behaviour (different courtship ritual, fertile at different times of the year)
• Genetic drift


  • The change in allele frequency within a population between generations
  • Parents don't produce genetically identical offspring to themselves (variation between parents & offspring)
  • Genetic drift happens in all populations but only has a bigger impact on small populations (the smaller the population the bigger the impact, fewer individuals so evolution also occurs faster)
  • Substantial genetic drift results in evolution (over many years)