There are 40 individuals in population 1, all with genotype A1A1, and there are 25 individuals in population 2, all with genotype A2A2. Assume that these populations are located far from each other and that their environmental conditions are very similar. Based on the information given here, the observed genetic variation is most likely an example of___________.
a. Genetic drift
b. Gene flow
c. Disruptive selection
d. Discrete selection
e. Directional selection
Answer:
a. Genetic drift
Explanation:
Genetic drift occurs when there are random changes in the frequencies of the alleles of a population. These changes occur due to any chance event and there is no natural selection operative on the adaptive traits. Since the two populations are present in habitats having similar environmental conditions, natural selection cannot cause the observed variations.
Therefore, these are the chance variations evolved by the process of genetic drift. For example, accidental removal of all the organisms having the allele A2 from population 1 could be the reason and the genetic drift fixed the allele A1 at the locus. Small sizes of the given populations also support it since genetic drift is more effective in smaller populations.
