Genetic diversity

• What is genetic diversity?

  • Number of different alleles of genes in a species or population, large number of different alleles = different characteristics.
• Genetic diversity is increased by:

  • Mutations in DNA forming new alleles
  • Different alleles introduced to population when individuals from another population migrate into it and reproduce = gene flow
• Genetic bottlenecks:

  • event causing a big reduction in a population. e.g when a large number of organisms die before reproducing.
  • This reduces No of different alleles in the gene pool so reduces genetic diversity.
  • Survivors reproduce and a larger population is created from a few individuals
• Founder effect:

  • describes what happens when just a few organisms from a population starts a colony, with a small number of different alleles in initial gene pool.
• Founder effect pt 2

  • Frequency of each allele in new colony different to original population, e.g an allurer rare in original might be more common in new colony = higher incidence of genetic disease.
• Founder effect occurs..

  • Result of migration leading to geographical separation from original population. egg religion