Does positive assortative mating affect allele frequency?

Final note: Although assortative mating on its own does not affect allele frequencies, when it is combined with natural selection they can have a significant affect on the rate of change in the allele frequencies at the locus subject to assortative mating.

What are the effects of assortative mating on genotype frequencies?

Assortative mating alone is not expected to change the frequencies of alleles, or ancestry fractions in the case of our study, within a population. Assortative mating does, however, change genotype frequencies, resulting in an excess of homozygous genotypes.

Does assortative mating decrease genetic variation?

Assortative mating has been suggested to result in an increase in heritability and additive genetic variance through an increase in linkage disequilibrium.

What does assortative mating do?

Assortative mating is the tendency for people to choose mates who are more similar (positive) or dissimilar (negative) to themselves in phenotype characteristics than would be expected by chance.

Does assortative mating cause evolution?

Like recombination, non-random mating can act as an ancillary process for natural selection to cause evolution to occur. Any departure from random mating upsets the equilibrium distribution of genotypes in a population. This will occur whether mate selection is positive or negative assortative.

Is assortative mating good or bad?

Assortative mating has reproductive consequences. Positive assortative mating increases genetic relatedness within a family, whereas negative assortative mating accomplishes the opposite effect.

How does gene flow affect allele frequency?

In humans gene flow usually comes about through the actual migration of human populations, either voluntary or forced. Although gene flow does not change allele frequencies for a species as a whole, it can alter allele frequencies in local populations.

How does assortative mating affect heritability?

Assortative mating for a heritable trait leads to a non-random distribution of the genetic variants important for that trait as spouses will be more similar genetically than expected by chance.

How does assortative mating affect evolution?

Clearly, an increase in assortative mating always reduces the number of intermediate phenotypes. Roughly speaking, higher levels of assortative mating evolve only if heterozygotes, i.e., intermediate phenotypes, are deleterious.

Why does non random mating affect allele frequencies?

That is an interesting result: non-random mating, even in the most extreme form of self- fertilization, has no effect on allele frequency. Selfing causes genotype frequencies to change as the frequency of homozygotes increases and the frequency of heterozygotes decreases, but the allele frequency remains constant.

Do assortative mating models change alleles?

Many assortative mating models do change allele frequencies because the proportion of individuals in the matings differs from the proportion in the population.

What is the difference between inbreeding and positive assortative mating?

Positive-assortative mating is in some ways analogous to inbreeding in that similar phenotypes, which might have similar genotypes, are more likely to mate than random individuals from the population. Some types of assortative mating are also similar to inbreeding in that they do not change allele frequencies but do affect genotype frequencies.

How does non-random mating affect Hardy-Weinberg equilibrium?

Non-random mating results in changes in the genotype frequencies in the population, i.e., how the alleles are put together into genotypes, but it does NOT change the allele frequencies themselves. Since genotype frequencies will be affected, non-random mating results in a deviation from Hardy-Weinberg equilibrium.

What are some examples of negative-assortative mating in plants?

Jiang et al. (2013) found few examples of negative-assortative mating in their review. Some examples are, however, in some plants where successful fertilization occurs only between individuals with different flower types.

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