Hardy-Weinberg

Equilibrium

Population Genetics and Evolution

Essential Knowledge

• 1A1: Natural selection is a major mechanism of evolution (1g: Conditions for

HW and 1h Math approaches to cal frequency).

• 1908: Hardy and Weinberg proposed that the frequency of alleles and genotypes in a pop. will remain constant from generation

to generation (equilibrium) if….

No Evolution Will Occur if…

• 5 conditions need to be met:

1. Large population size

2. Random mating

3. No net mutations of alleles

4. Absence of migration

5. Absence of natural selection

Why is this most likely never to happen with humans??

It’s a Mathematical Model!

Allelic frequencies:

p + q = 1, p is freq of dominant allele (A) and q is freq of recessive allele (a).

Genotypic frequencies:

p2 + 2pq + q2= 1, p2 is homozygous dom., 2pq is heterozygous, and q2 is homozygous

recessive.• Must use %!

Our Activity

• PTC paper will be distributed.

• Taste the paper. If bitter, you are dominant for the taster allele (AA or Aa)

• If no taste, you are recessive for the taster allele (aa).

• Calculate the p and q values in the data table.