Zoos

• Why are zoos important?

  1. Centres of scientific research
  2. Captive breeding programmes
  3. Reintroduction of species
  4. Education about different species
• What do captive breeding programmes do?

  Increase the population of a species. This allows genetic diversity to be maintained in a captive population. Therefore reducing the extinction of species.

  • however, it can lead to inbreeding depression and genetic drift
• What are studbooks?

  Records that track which individuals of the same species have mated to prevent inbreeding.
• What is genetic drift?

  Change in allele frequency over time due to chance.

  • can lead to a reduction in genetic diversity and lead to loss of alleles from the population.
  • this has a larger impact on smaller populations
• What is inbreeding depression?

  In a small population, there is an increase in mating between closely related individuals.

  • the no. of homozygous individuals increases, increasing recessive alleles
  • no. of heterozygous individuals decreases
  • as a result, less fit offspring is produced with lower lifespan
• How to know if a population is inbred?

  They have low genetic diversity due to:

  • low heterozygous individuals
  • high no. of homozygous individuals with recessive alleles.
• Why might animals in captivity not be released into the wild?

  • they are needed for the captive breeding programme
  • they aren't ready to be reintroduced into the wild
  • they would be at risk of predators if released