A gene for eye color in an island fly species has two alleles: the dominant allele codes for blue eyes, and the recessive allele codes for green eyes. If genetic drift is the only force that changes allele frequencies in a fly population, what is expected to happen to the blue and green eye allele frequencies in the population?

The changes in the frequencies of blue and green eye alleles can not be predicted since genetic drift is a random event.

Explanation:

Genetic drift is the change in the allele frequencies of a population caused by some chance event. The effect of genetic drift is more pronounced in smaller populations since random events cause changes of greater magnitude in a small population. It can cause the complete loss of an allele from a small population.

According to the given information, the frequencies of alleles for green and blue eyes are changed by genetic drift which in turn would produce random evolutionary changes Either of the alleles may be eliminated from the population irrespective of the fact that the allele is beneficial or harmful. Thus, genetic drift would change the frequencies of the allele in an unpredictable manner.