Genetic (Hardy-Weinberg) Equilibrium

Genetic (Hardy-Weinberg) Equilibrium occurs in a theoretical non-evolving population. In order for this to occur several assumptions are made:

• No natural selection is occuring.
  
  
• No mutations are occuring.
  
  
• No gene flow is occuring.
  
  
• No genetic drift is occuring.
  
  
• Mating is random.

In Hardy-Weinberg, the allele frequencies are represented by the letter p and q. The frequencies of both alleles (p + q) add up to one hundred percent. Diploid organisms each have two alleles. So the probability that both alleles are p is represented by p². The probability that both alleles are q is represented by q². The probability that the organism is heterozygous is 2pq.