Final answer:
Both selection against a dominant gene and selection against a recessive gene can lead to changes in gene frequencies, but their significance depends on several factors.
Step-by-step explanation:
Both selection against a dominant gene and selection against a recessive gene can lead to changes in gene frequencies, but their significance depends on several factors.
Selection against a dominant gene can result in a more immediate and noticeable change in gene frequencies. This is because dominant genes are expressed in the phenotype of individuals carrying the allele, making it easier to identify and select against. However, the effect of selection against a dominant gene may be limited if the dominant allele is also advantageous in terms of reproductive success.
On the other hand, selection against a recessive gene may result in a slower and less noticeable change in gene frequencies. This is because recessive genes are only expressed in the phenotype when an individual is homozygous for the recessive allele. As a result, the recessive allele may remain hidden in the population, even if it is unfavorable in terms of reproductive success.
Overall, the significance of selection against a dominant or recessive gene in changing gene frequencies depends on the specific allele and its effects on reproductive success.