Explain why most mutations in eukaryotes are recessive

There are two main reasons. First, there are introns and exons existed in eukaryotes. Introns do not contain the genetic information but are in large amount in chromosome. So, if the mutation occurs in the introns, it will be recessive. Second, one amino acid will corresponding to several base sequences. For example, UUU and UUC all represent Phe. This is called degeneracy. So if the mutation did not change the amino acid, it is also recessive.

Two European men and two Polynesian women settled on a previously uninhabited tropical island. All four of the settlers have brown eyes, a dominant trait, but one of the Europeans is heterozygous and carries the recessive gene for blue eyes.  No new settlers arrive,and nobody leaves the island.After a few generations,the percentage of blue-eyed individuals increases from the original zero to 25 percent.This is probably due to which of the following factors?

genetic drift

Explanation:

Genetic drift entails when there are changes in the gene frequency which occur in a gene that is existing. From the analogy above, it is a known fact that only gneetic drift could allow such to happen as mutation will only occur with a sudden change of gene which is not the case described above