Recessive alleles seem to vanish in some generations and reappear in later generations because:

Question

Quizplus · Accepted Answer

Recessive alleles are masked by dominant ones, meaning that they are not expressed in the phenotype. However, they can still be passed down to offspring and may reappear in later generations if an individual inherits two copies of the recessive allele (one from each parent) and there is no dominant allele present to mask its expression.

Recessive Alleles Seem to Vanish in Some Generations and Reappear