Why is The Hardy Weinberg Equilibrum Important

The Hardy- Weinberg Equilibrium principle is very important to the scientific genetic society as;

• It is the foundation of which almost all the theory of population genetic of sexually- reproducing organisms is based

• It is a NULL MODEL

• Deviations give evidence of selection, Genetic drift, gene flow, mutation or non random mating in a population

 

ASSUMPTIONS AND VIOLATIONS OF THE HARDY WEINBERG EQUILIBRUM

 

• All individuals have equal probabilities of surviving and reproducing. Violated if NATURAL SELECTION (differential reproductive success) occurs

 

• The population is infinitely large. Violated by GENETIC DRIFT

 

 

• Genes are not added to or removed from the population by migration. Violated by GENE FLOW

 

 

• There is no MUTATION

 

 

• Mating is random. Violated e.g. by INBREEDING AND SEXUAL SELECTION

 

 

 

@Science_nerd101 (twitter)

The Hardy- Weinberg Equilibrum

For a 2 allele situation the Hardy- Weinberg Equilibrium is the best to use......

REMEMBER THIS...

p2 + 2pq + q2 = 1

 

P and Q are the frequencies of the alleles A and a

 

 

p2 + 2pq + q2 = 1

(AA)  +  (Aa)  +  (aa) = 1

 

 

At the Equilibrium, allele frequency does not change over time

 

 

EXAMPLE;

 

A particular species of fish is rarely seen, however we can find eggs and sperm in the water

(these are haploid = 1)  

 

• The dominant allele 'R' codes for red scale colour
• The recessive allele 'r' codes for white scale colour

80% where 0.8 had  Dominate 'R'

20% where 0.2 had recessive 'r'

 

RR (p2)- 0.8 x 0.8 = 0.64

Rr (pq)- 0.8 x 0.2 = 0.16

rR (pq)- 0.2 x 0.8 = 0.16

rr (q2) - 0.2 x 0.2 = 0.04

 

add all the numbers together the total should = 1

Why is Hardy Weinberg Equilibrium Important?

@Science_Nerd101 (Twitter)