Question

The Afrikaner population of Dutch settlers in South Africa is descended mainly from a few colonists. Today, the Afrikaner population has an unusually high frequency of the gene that causes Huntington's disease. Huntington's disease is an autosomal dominant disease and only one allele is needed for the disease (HH, Hh). The Afrikaners are an example of a founder effect. It is also an example of genetic drift. How is the founder effect related to the concept of genetic drift?

A) Reduced genetic variation of this small population means that the population may not be able to adapt to new selection pressures.
B) In a small population, the more advantageous trait becomes more common. If this continues, eventually, all individuals in the population will have Huntington's disease.
C) The small population size means that the new colony may have reduced genetic variation from the original population and that variation, in this case, included the dominant allele for Huntington's disease.
D) There are three sources of genetic variation: gene flow, sexual reproduction and mutation. In the case of the Afrikaners, once the settlers arrived in Africa, these three sources had little impact on the gene pool and variation.

Answer 1

C) The small population size means that the new colony may have reduced genetic variation from the original population and that variation, in this case, included the dominant allele for Huntington's disease.

Step-by-step explanation:

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Answer 2

The correct option is C) The small population size means that the new colony may have reduced genetic variation from the original population and that variation, in this case, included the dominant allele for Huntington's disease.

Step-by-step explanation:

The Afrikaner population of Dutch settlers in South Africa is descended mainly from a few colonists. Today, the Afrikaner population has an unusually high frequency of the gene that causes Huntington's disease, because those original Dutch colonists just happened to carry that gene with unusually high frequency. This effect is easy to recognize in genetic diseases, but of course, the frequencies of all sorts of genes are affected by founder events.