Hardy-Weinberg Theorem

  genetic variation
    single gene mutation
    chromosomal changes
        gene duplication
    exon shuffling
    sexual recombination
  1. Applies in a very large population with:
    1. no natural selection.
    2. no migration.
    3. no mutation.
    4. random mating.
  2. The frequency of alleles in the gene pool remains the same.
  3. Example: think of it as shuffling a deck of cards.
  4. Let p = frequency of one allele; q = frequency of another allele.
  5. The total number of alleles for the locus = 100% of the population.
  6. Expressed as a formula: p + q = 1
  7. p2 + 2pq + q2 = 1
  8. Hardy-Weinberg shows mathematically that a population will remain stable UNLESS: acted upon by the forces which lead to evolution.