Question

1) The Afrik aner population of Dutch settlers in South Africa is descended mainly from a few colonists. Today, the Afrik aner 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 Afrik aners 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, se xual reproduction, and mutation. In the case of the Afrik aners, once the settlers arrived in Africa, these three sources had little impact on the gene pool and variation.

Answer 1

Answer:

C.

Explanation:

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. Genetic drift, along with natural selection, mutation, and migration, is one of the basic mechanisms of evolution. In this case, it was a chance that the settlers all carried the allele for Huntington's disease.