Hardy Weinberg

Hardy Weinberg refers to

Populations

Hardy Weinberg Equilibrium

•What it is?

•A way to measure evolution in a population

•Allele frequency will not change from generation to generation if a population is not evolving.

These are your alleles

Genotype?

B b

Phenotype?

What is the allele frequency

in the room?

Let’s set up a data table to record our allele frequencies.

Let’s Reproduce...Meiosis Anyone?

Then into the gene pool

This is This is

more likemore like spawningspawning

What is our new allele frequency?

1. Natural Selection2. Calculate survivor allele frequency3. SURVIVORS only...Reproduce4. Next generation

H-W Equilibrium says Allele Frequency will remain the same from generation to

generation...DID IT?

Oh Wait...

Hardy Weinberg Conditions

1. No mutation

2. Random Mating

3. Large Population

4. No Natural Selection

5. No emigration/immigration

Science Practice 1

•The student can use representations and models to communicate scientific phenomena and solve scientific problems.

•Model : Reproductive isolation.

•Model: genetic drift

•Model: non-random mating

•Model: mutation

•Model: emigration/immigration

How do we use the H-W Formula?

•p2 + 2pq + q2 = 1

1919

Hardy-Weinberg describes the status quo and Hardy-Weinberg describes the status quo and provides a way to describe change.provides a way to describe change.

5 conditions must be met:5 conditions must be met:

Allele frequencies wonAllele frequencies won’’t change if…t change if…

1. The population is large1. The population is large

2. Mating is random2. Mating is random

3. There is no mutation 3. There is no mutation

4. No immigration or emigration4. No immigration or emigration

5. There is no selection5. There is no selection

2020

All the alleles in a population must All the alleles in a population must equal 100%equal 100%

Say A and a are the alleles at a locusSay A and a are the alleles at a locus

Diploid organisms have 2 lociDiploid organisms have 2 loci

p = the frequency of Ap = the frequency of A

q = the frequency of aq = the frequency of a

So the frequency of p + q must equal 100% So the frequency of p + q must equal 100% or 1.0or 1.0

2121

Frequency of possible combinations of p Frequency of possible combinations of p and q for diploid organismsand q for diploid organisms

• (p+q) (p+q) =(p+q) (p+q) =

pp22 + 2pq + q + 2pq + q22

•In a population of 1000 individuals, 360 of the individuals have an attached earlobe, a recessive trait. This population is in Hardy Weinberg equilibrium. How many individual are heterozygous for this trait?

Scotland has the highest percentage of redheads in the world at 13%. Assuming Hardy Weinberg equilibrium, calculate the frequency of p and q.