Question

Understand how non-random mating can influence genotype frequencies, and be able to illustrate graphically why non-random mating alone will not change allele frequencies?

A) Non-random mating can increase genetic diversity by promoting random mate selection.

B) Non-random mating can decrease genetic diversity by encouraging assortative mating based on similar traits.

C) Non-random mating has no impact on genotype frequencies or allele frequencies.

D) Non-random mating can influence genotype frequencies by altering the distribution of mating pairs but does not directly change allele frequencies.

Answer 1

Non-random mating affects genotype frequencies but not allele frequencies; even assortative mating patterns merely redistribute the alleles without affecting their overall prevalence in the gene pool.

Step-by-step explanation:

Non-random mating can influence genotype frequencies in a population by the patterns in which individuals choose their mates. In assortative mating, individuals preferentially mate with partners who are phenotypically similar to themselves which can decrease genetic diversity. However, non-random mating, while it can shift genotype frequencies due to the non-random pairing of alleles, does not change allele frequencies directly since the total number of each allele in the population remains the same.

Under circumstances such as the Hardy-Weinberg equilibrium, allele and genotype frequencies in a population will remain stable unless evolutionary forces act upon them. This equilibrium assumes random mating along with no other evolutionary forces such as mutation, natural selection, genetic drift, or migration. Thus, though non-random mating alone can affect which genotypes are more common or rare by altering mating patterns (e.g., phenotype-based mate selection), it won't alter the frequency of alleles because the alleles represented in the gene pool aren't being selectively added or removed solely by mate choice.