September 17- HWE

The HWE, aka, Hardy Weinberg Equilibrium is the principle that the genetic variation in a population will remain constant from one generation to the next in the absence of disturbing factors. For example, mutations disrupt the equilibrium of allele frequencies by introducing new alleles into a population. This equilibrium states that there is no selection, no mutation, no migration, etc. NO OUTSIDE FACTORS.

The HWE uses an equation:

The Problems given in lecture were:

In dwarbs the allele for a black tongue is recessive. In a population of 800 dwarbs 25 have black tongues. 

1. what percentage of the population has black tongues? 3.1%

2. what are the frequencies of the dominant and recessive alleles? dominant: 0.824

 recessive: 0.176

3. what percentage of the population are heterozygous for this trait? 29%

The delta-32 mutation, a recessive allele, gives humans protection from HIV infection. The frequency of this allele in a certain town is 20%. 

1. what percentage of the population is homozygous for the allele conferring HIV immunity? 4%

2. what percentage of the population is not immune but is capable of having children that are immune? 32%

My own problem is:

There are 45 brown dobermans within a population of 500 dobermans. Brown fur is the recessive allele and Black fur is the dominant allele. 

1. What percentage of dobermans are heterozygous for this trait? 42%

2. What percentage of the population has brown fur? 9%