ka7: components of biodiversity

• 1. The Biodiversity of Planet Earth

  Scientists estimate that there are up to 8.7 million species of living thing on planet earth but the vast majority have not been identified - and cataloguing them all could take more than 1,000 years.

   
• 1. Components of biodiversity

  There are three measurable components of biodiversity:

   

  • Genetic diversity

  This is the number and frequency of all the alleles within a population.

   

  Genetic diversity comprises the genetic variation represented by the number and frequency of all the alleles in a population.

   

  If one population of a species dies out then the species may have lost some of its genetic diversity, and this may limit its ability to adapt to changing conditions.
• • Species diversity

  This comprises the number of different species in an ecosystem (the species richness) and the proportion of each species in the ecosystem (the relative abundance).

   
• • Ecosystem Diversity

  This refers to the number of distinct ecosystems within a defined area.
• Components of biodiversity

  • Genetic diversity
  • Species diversity
  • Ecosystem diversity
• Genetic diversity


  The number and frequency of all the alleles within a population
• If one population of a species dies out then the species may have lost some of its genetic diversity, and this may limit its ability to adapt to changing conditions
• Species diversity


  Comprises the number of different species in an ecosystem (the species richness) and the proportion of each species in the ecosystem (the relative abundance)
• A community with a dominant species has a lower species diversity than one with the same species richness but no particularly dominant species
• Ecosystem diversity


  Refers to the number of distinct ecosystems within a defined area