When nonrandom mating occurs in a population?

Last Update: May 30, 2022

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Asked by: Dr. Autumn Ferry II
Score: 4.9/5 (42 votes)

When a population interbreeds, nonrandom mating can sometimes occur because one organism chooses to mate with another based on certain traits. In this case, individuals in the population make specific behavioral choices, and these choices shape the genetic combinations that appear in successive generations.

What is the effect of nonrandom mating on the gene pool of a population?

Evolutionary Consequences of Non-random Mating

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.

What is an example of nonrandom mating?

Nonrandom mating is a phenomenon that individuals choose their mates based on their genotypes or phenotypes. Examples of this kind of mating occur in species like humans, peacocks, and frogs. Nonrandom mating can happen in many different forms, one being assortative mating.

How does nonrandom mating affect allele frequencies in a population?

Non-random mating won't make allele frequencies in the population change by itself, though it can alter genotype frequencies. This keeps the population from being in Hardy-Weinberg equilibrium, but it's debatable whether it counts as evolution, since the allele frequencies are staying the same. Gene flow.

What phase does random mating occur?

In meiosis I, crossing over during prophase and independent assortment during anaphase creates sets of chromosomes with new combinations of alleles. Genetic variation is also introduced by random fertilization of the gametes produced by meiosis.

Non-random mating

23 related questions found

What are the 5 Hardy Weinberg assumptions?

The Hardy–Weinberg principle relies on a number of assumptions: (1) random mating (i.e, population structure is absent and matings occur in proportion to genotype frequencies), (2) the absence of natural selection, (3) a very large population size (i.e., genetic drift is negligible), (4) no gene flow or migration, (5) ...

What is random mating?

In genetics, random mating (panmixia) involves the mating of individuals regardless of any physical, genetic, or social preference. In other words, the mating between two organisms is not influenced by any environmental, hereditary, or social interaction. Hence, potential mates have an equal chance of being selected.

Does assortative mating affect allele frequencies?

Assortative mating is nonrandom mating based on phenotypes rather than between relatives. ... Some types of assortative mating are also similar to inbreeding in that they do not change allele frequencies but do affect genotype frequencies.

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. (Elk, elephant seals, horses, lions, etc.) Commonly, the males of such species are much larger than the females.

How do you calculate random mating?

Random mating - Random mating refers to matings in a population that occur in proportion to their genotypic frequencies. For example, if the genotypic frequencies in a population are MM=0.83, MN=0.16 and NN=0.01 then we would expect that 68.9% (0.83 x 0.83 X 100) of the matings would occur between MM individuals.

Why is random mating important?

Any departure from random mating upsets the equilibrium distribution of genotypes in a population. A single generation of random mating will restore genetic equilibrium if no other evolutionary mechanism is operating on the population.

What is the difference between assortative and Disassortative mating?

Assortative mating and disassortative mating are two phenomena that result in the mating of organisms in a species. Assortative mating results from the mating between two organisms showing similar phenotypes. However, disassortative mating results from the mating between two organisms showing dissimilar phenotypes.

Do plants mate randomly?

In small populations with a limited number of potential mates, such matings between relatives are also common. Second, most flowering plants are hermaphroditic or monoecious. Thus, individual plants produce both male and female gametes and are capable of self-fertilization, the most extreme form of inbreeding.

Does random mating increase heterozygosity?

Disassortative mating will tend to increase heterozygosity (put unlike alleles together) without affecting gene frequencies. Rare allele advantage. ... Rare allele advantage will tend to increase the frequency of the rare allele and hence increase heterozygosity.

Why is random mating important to Hardy Weinberg?

If allele frequencies differ between the sexes, it takes two generations of random mating to attain Hardy-Weinberg equilibrium. Sex-linked loci require multiple generations to attain equilibrium because one sex has two copies of the gene and the other sex has only one.

Is genetic drift random?

Genetic drift describes random fluctuations in the numbers of gene variants in a population. Genetic drift takes place when the occurrence of variant forms of a gene, called alleles, increases and decreases by chance over time. These variations in the presence of alleles are measured as changes in allele frequencies.

What are two kinds of non random mating?

READING: Nielsen & Slatkin, pp. 13–16, 59-63, 198-205 •Will distinguish two types of nonrandom mating: (1) Assortative mating: mating between individuals with similar phenotypes or among individuals that occur in a particular location. (2) Inbreeding: mating between related individuals.

Is assortative mating adaptive?

Even though in the models presented speciation requires the genetic potential for strong assortment as well as rather restrictive ecological conditions, the results show that adaptive speciation due to the evolution of assortative mating when mate choice is based on separate female preference and male marker traits is ...

Does assortative mating increase genetic diversity?

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

Why does assortative mating not necessarily lead to a change in allele frequencies?

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 is an example of assortative mating?

Examples of species that display this type of assortative mating include the jumping spider Phidippus clarus and the leaf beetle Diaprepes abbreviatus. In other cases, larger females are better equipped to resist male courtship attempts, and only the largest males are able to mate with them.

What does mating mean in biology?

In biology, mating is the pairing of either opposite-sex or hermaphroditic organisms for the purposes of sexual reproduction. ... Mating may also lead to external fertilization, as seen in amphibians, fishes and plants. For the majority of species, mating is between two individuals of opposite sexes.

What do you mean by inbreeding?

Inbreeding, the mating of individuals or organisms that are closely related through common ancestry, as opposed to outbreeding, which is the mating of unrelated organisms.

What is genetic drift example?

Genetic drift is a change in the frequency of an allele within a population over time. ... A population of rabbits can have brown fur and white fur with brown fur being the dominant allele. By random chance, the offspring may all be brown and this could reduce or eliminate the allele for white fur.

What is gene flow class 12?

- Gene flow, also referred to as gene migration, is the introduction from one population of one species to another of genetic material (by interbreeding), thus altering the composition of the gene pool of the receiving population.