# Hardy-Weinberg Theorem

genetic variation
single gene mutation
chromosomal changes
gene duplication
exon shuffling
sexual recombination

- Applies in a very large population with:
- no natural selection.
- no migration.
- no mutation.
- random mating.

- The frequency of alleles in the gene pool remains the same.
- Example: think of it as shuffling a deck of cards.
- Let p = frequency of one allele; q = frequency of another allele.
- The total number of alleles for the locus = 100% of the population.
- Expressed as a formula: p + q = 1
- p
^{2} + 2pq + q^{2} = 1
- Hardy-Weinberg shows mathematically that a population will remain stable UNLESS: acted upon by the forces which lead to evolution.