A Small Dutch Population Settled in South Africa in the 17th Century
A small dutch population settled in south africa in the 17th centrury and became known as afrikaners
By chance a few dutch settlers carried the gene for huntingtons disease. Today huntingtons disease occurs at a relatively high frequency in this population. This is an example of_____.
Explanation:
A mutation can be described or explained as a change that occurs in the DNA sequence, either due to mistakes when the DNA is copied or as a result of environmental factors. This means that the occurrence of Huntington's disease in high frequency is because of mutation. This is possible because during the settlement of the Dutch in the 17th century in South Africa, they might have had intercourse with the people that have the disease and inherited it. They will be transferring the gene with the trait of the disease from one person to another through sex, resulting in a high number of the disease in their population.
The founder effect is a special case of genetic drift, where a few organisms of one population settle down in a new area carrying the genes of the original population.
Genetic drift is the random change in the allelic frequency in a population, from one generation to the other. The magnitude of this change is inversely related to the size of the original population. These changes produced by genetic drift accumulate in time, and eventually, some alleles get lost, while some other might set.
Founder effect refers to the consequences that occur from the origin of a new population that derives from a small number of founder individuals that come from an ancestral bigger population. This small group shows poor genetic variation and a high possibility of expressing a peculiar allelic composition. In the exposed example, the principal consequence is the increasing number of individuals with Huntington's disease.
If the number of individuals that originated the new population is very low, the founder effect will be very extreme, because the effects of the genetic drift are inversely proportional to the original number of individuals, which in this example, is the small Dutch population settled in South Africa in the 17th century.