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.
How does random mating affect genotype frequency?
Random mating prevents change in allele frequency (as described in Hardy Weinberg law) in a population when other evolutionary forces are not acting; though that does not happen in nature.
What effects can non-random mating have on genotypes?
Although nonrandom mating does not change allele frequencies from one generation to the next if the other assumptions hold, it can generate deviations from expected genotype frequencies, and it can set the stage for natural selection to cause evolutionary change.
What process can affect genotype frequencies?
The four factors that can bring about such a change are: natural selection, mutation, random genetic drift, and migration into or out of the population. (A fifth factor—changes to the mating pattern—can change the genotype but not the allele frequencies; many theorists would not count this as an evolutionary change.)
Is random mating considered an evolutionary force?
Random mating – Random mating refers to matings in a population that occur in proportion to their genotypic frequencies. … No evolutionary forces affecting the population – These forces may or may not be at work on a population, and we will discuss them in more detail later.
How does random mating cause variation?
Mendelian segregation has the property that random mating results in an equilibrium distribution of genotypes after only one generation, so genetic variation is maintained. … The equilibrium is the direct consequence of the segregation of alleles at meiosis in heterozygotes.
What is the reason for non-random mating?
Non-random mating means that mate selection is influenced by phenotypic differences based on underlying genotypic differences. In some species, males acquire harems and monopolize females.
Why is human mating usually not random?
In all human populations, people usually select mates non-randomly for traits that are easily observable. Cultural values and social rules primarily guide mate selection. … When they select mates for their animals based on desired traits, farmers hope to increase the frequency of those traits in future generations.
What does non-random mating cause?
As the discriminated traits are genetically inherited, evolution is usually a consequence. 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.
What are two factors that change gene frequencies in a population?
Factors that disturb the natural equilibrium of gene frequencies include mutation, migration (or gene flow), random genetic drift, and natural selection.
What are five factors that can change genotype frequencies in populations?
Five factors are known to affect Hardy- Weinberg genetic equilibrium such as genetic drift, gene flow, mutation, non-random mating and natural selection.