Populations

• define species

  A group of organisms that can interbreed to produce fertile offspring
• Define population

  All organisms of a particular species that live in the same place
• Define gene pool

  The range of different alleles existing for a particular locus within a population
• Define allele frequency

  ~The proportion of a certain allele within a gene pool

  ~Expressed as a decimal or percentage
• What is the Hardy-Weinberg principle

  Allows us to estimate the frequency of alleles in a population, as well as if the allele frequency is changing over time
• Give the assumptions made by the Hardy-Weinberg principle


  ~No mutations occur to create new alleles

  ~No migration in or out of the population

  ~No selection, so alleles are all equally passed on to the next generation

  ~Random mating

  ~Large population
• Explain the Hardy-Weinberg equation for calculating allele frequency


  ~The frequencies of each allele for a characteristic must add up to 1.0

  ~The equation is therefore p+q=1

  ~Where p = frequency of the dominant allele and q = frequency of the recessive allele
• Explain the Hardt-Weinberg equation for calculating genotype frequency

  ~The frequencies of each genotype for a characteristic must add up to 1.0

  ~The equation is therefore p2+2pq=q2=1

  ~Where p2 = frequency of homozygous dominant, 2pq = frequency of heterozygous, and q2 = frequency of homozygous recessive