Biology 196: Hardy Weinberg Equation (PWPT 6)

If there are two or more alleles for a locus, what can individuals be?

homozygous or heterozygous

How do you find the total amount of dominant alleles? (MATH EQUATION)

Total dominant alleles=(2×# AA individuals)+(1×# Aa individuals)

How do you find the total amount of recessive alleles? (MATH EQUATION)

Total recessive alleles=(2×# aa individuals)+(1×# Aa individuals)

Suppose in a population there are:

• 10 individuals AA (Homozygous recessive)

• 5 individuals Aa (Heterozygous)

• 0 individuals aa (Homozygous recessive)

How many dominant alleles and recessive alleles are there?

Dominant alleles:

(2×10)+(1×5)=20+5= 25

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Recessive alleles:

(2×0)+(1×5)=0+5= 5

If there are two alleles at a locus, what represents their frequencies?

p and q are used to represent their requecies

What does the frequency of all alleles in a population add up to?

Sooooooooo, p+q=1 broski

Find the Genotype Frequency for the following problem

Calculate the number or copes of each allele in the following problem.

Calculate the frequency of each allele for the following problem:

Check the answer:

p+q=1 —> 0.8+0.2= 1 ✅

What does the Hardy-Weinberg equation describe?

the genetic makeup we expect for a population that is NOT evolving at a particular locus

• allele and genotype frequencies remain constant from generation to generation

  • if above is true, the population is in Hardy-Weinberg equilibrium

What does deviation from H-W equilibrium indicate?

the population is evolving at the locus

If p and q represent the relative frequencies of the only two possible alleles in a population at a locus, what can we expect?

expect genotype frequencies can be calculated assuming random mating

Example Problem Cont:

• Calculate the equilibrium genotype frequencies

Calculate the equilibrium phenotype numbers

What are the five conditions that if met allele frequencies will be constant over time and the population is not evolving?

1) No mutation

2) Random Mating

3) No Natural selection

4) Extremely large population size (little genetic drift)

5) No movement of individuals between populations (No gene flow)