- The document discusses the Hardy-Weinberg law of population genetics as described by Hardy and Weinberg in 1908-1909. - It states that gene and genotype frequencies in a population remain constant from generation to generation if the population is large, there is no gene flow or evolutionary influences like selection, mutation, migration, or genetic drift. - The Hardy-Weinberg model uses two equations to calculate allele and genotype frequencies based on the frequencies of dominant and recessive alleles in a population.

1. HARDY WEINBERG LAW
PRIYA DIXIT
DEPARTMENT OF BIOTECHNOLOGY
ERA UNIVERSITY, LUCKNOW

2. • Population genetics is the study of the allelic,
genotypic, and phenotypic variation in a population.
• According to Hardy ( England, 1908) and weinberg (
Germany 1909) gene and genotype frequency of a
mendelian population remain constant generation after
generation unless there is selection, mutation, migration
or random drift.
• The Hardy-Weinberg equilibrium gives us a tool to
observe how populations evolve (or don't). It states that
the frequencies of alleles and genotypes will stay the
same through the generations as long as there are no
evolutionary influences.

3. Assumptions : The model has five basic assumptions
1) The population is large
2) There is no gene flow between populations
3) Mutations are negligible
4) Individuals are mating randomly
5) Natural selection is not operating on the population
Variables
p: frequency of one of two alleles , q: frequency of the other of two alleles
Methods
The Hardy-Weinberg model consists of two equations.
• Allele frequencies and Genotype frequencies p+q=1 describes allele frequencies
for a gene with two alleles.
• The equation for genotype frequencies is p2+ 2pq + q2 = 1.
• 𝑝 is the frequency of the dominant allele.
• 𝑞 is the frequency of the recessive allele.
• 𝑝² is the frequency of individuals with the homozygous dominant genotype.
• 2𝑝𝑞 is the frequency of individuals with the heterozygous genotype.
• 𝑞² is the frequency of individuals with the homozygous recessive genotype.

4. Importance
The Hardy-Weinberg equilibrium is a beneficial tool
that helps scientists determine whether populations
will evolve or not.

5. Thank you