Meiotic recombination initiates with double-stranded breaks that are introduced into the DNA by the Spo11 protein.

Meiotic division I goes on in the ovulated oocyte stimulated by luteinizing hormones ( LHs ) produced by the pituitary gland.

* Meiotic drive: In hybrid populations, selfish genetic elements inactivate sperm cells ( i. e.: an X-linked drive factor inactivates a Y-bearing sperm and vice versa ).

Meiosis generates genetic diversity in two ways: ( 1 ) independent alignment and subsequent separation of homologous chromosome pairs during the first meiotic division allows a random and independent selection of each chromosome segregates into each gamete ; and ( 2 ) physical exchange of homologous chromosomal regions by homologous recombination during prophase I results in new combinations of DNA within chromosomes.

The shuffling of genes brought about by genetic recombination is thought to have many advantages, as it is a major engine of genetic variation and also allows sexually reproducing organisms to avoid Muller's ratchet, in which the genomes of an asexual population accumulate deleterious mutations in an irreversible manner.

In sexual populations, the process of genetic recombination allows the genomes of the progeny to be different from the genomes of the parents.

The applied voltage allows the device to work continuously by mopping up electrons which prevents the device from becoming saturated, and by preventing the recombination of ion pairs.

# Figure Mixer allows the creative recombination of the features of different figures ( DS3A only )

Natural evolution is a good analogy to this method – the rules of evolution ( selection, recombination / reproduction, mutation and more recently transposition ) are in principle simple rules, yet over millions of years have produced remarkably complex organisms.

Chimerism may be due to either co-ligation of multiple genomic segments into a single YAC, or recombination of two or more YACs transformed in the same host Yeast cell.

The universe was opaque before recombination because photons scatter off free electrons ( and, to a significantly lesser extent, free protons ), but it became transparent as more and more electrons and protons combined to form hydrogen atoms.

In molecular biology, SSB protein domain in bacteria are important in its function of maintaining DNA metabolism, more specifically DNA replication, repair and recombination.

It is not the same as linkage, which is the presence of two or more loci on a chromosome with limited recombination between them.

Plasmids become unstable after a certain amount of DNA has been inserted into them, because their increased size is more conducive to recombination.

He had made an invalid simplifying assumption which negated his assumption of constant population size, and had also incorrectly assumed that two mutations would take twice as long to reach fixation as one, while sexual recombination means that two can be selected simultaneously so that both reach fixation more quickly.

These diseases are associated with high incidence of chromosomal abnormalities, including chromosome breaks, complex rearrangements, deletions and translocations, site specific mutations, and in particular sister chromatid exchanges ( more common in BS ) that are believed to be caused by a high level of somatic recombination.

This leads to an increase in the count of recombination centers and deep-level defects, reducing the lifetime of minority carriers, thus affecting bipolar devices more than CMOS ones.

In CMOS devices, the radiation creates electron – hole pairs in the gate insulation layers, which cause photocurrents during their recombination, and the holes trapped in the lattice defects in the insulator create a persistent gate biasing and influence the transistors ' threshold voltage, making the N-type MOSFET transistors easier and the P-type ones more difficult to switch on.

After observing that a particular rII mutant, a mutation that caused the bacteriophage to eliminate bacteria more rapidly than usual, was not exhibiting the expected phenotype, it occurred to Benzer that this strain might have come from a cross between two different rII mutants ( each having part of the rII gene intact ) wherein a recombination event resulted in a normal rII sequence.

Given the new importance that IBD alleles are assuming in genetic association studies, a new definition of IBD that would better suit the underlying inheritance property would be that two or more alleles are identical by descent ( IBD ) if they have been inherited from the same ancestral allele without recombination events.

One of the more promising techniques of proper gene insertion is homologous recombination.

" Unlike neo-Darwinism, which regards mutation as merely raw material and natural selection as the creative power, Nei's mutationism assumes that the most fundamental process for adaptive evolution is the production of functionally more efficient genotypes by mutation ( especially birth and death of duplicated genes ) and by recombination.

It is not the same as linkage, which is the phenomenon whereby two or more loci on a chromosome have reduced recombination between them because of their physical proximity to each other.

In 1947, the microbiologist Joshua Lederberg showed that bacteria — which had been assumed to reproduce only asexually through binary fission — are capable of genetic recombination, which is more similar to sexual reproduction.

Today, scientists understand that independent assortment occurs when the genes affecting the phenotypes are found on different chromosomes or separated by a great enough distance on the same chromosome that recombination occurs at least half of the time.

The reason 0. 5 is used in the denominator is that any alleles that are completely unlinked ( e. g. alleles on separate chromosomes ) have a 50 % chance of recombination, due to independent assortment.

Genetic variation can also be produced by the recombination of chromosomes that occurs during sexual reproduction, called independent assortment.

Although an autosomal chromosome contains genes that are passed down from parents to children via independent assortment from only one of the two parents, genetic recombination ( chromosomal crossover ) mixes genes from non-sister chromatids from both parents during meiosis, thus changing the genetic composition of the chromosome.

# Evolution is gradual: small genetic changes, recombination ordered by natural selection.

This genetic diversity can provide the variation of physical and behavioural attributes ( phenotypes ) upon which natural selection can act, but, as described below in Section 6, Origin and function of meiosis, the genetic diversity may be largely a by-product of the homologous recombination that is primarily employed for its DNA repair function during meiosis.

' Modern biotechnology ' is defined in the Protocol to mean the application of in vitro nucleic acid techniques, or fusion of cells beyond the taxonomic family, that overcome natural physiological reproductive or recombination barriers and are not techniques used in traditional breeding and selection.

Later, after the completion of the modern synthesis, the term neo-Darwinism came to be associated with its core concept: evolution, driven by natural selection acting on variation produced by genetic mutation, and genetic recombination ( chromosomal crossovers ).

An EA uses mechanisms inspired by biological evolution: reproduction, mutation, recombination, and selection.

Ham accepts that natural selection can give rise to a number of species from an original population, by Mendelian recombination of already existing genes, but that new genes cannot arise from mutations, because this would be " adding information " ( he claims that only intelligence can cause a beneficial mutation ).

Evolutionary algorithms form a subset of evolutionary computation in that they generally only involve techniques implementing mechanisms inspired by biological evolution such as reproduction, mutation, recombination, natural selection and survival of the fittest.

Fitness proportionate selection, also known as roulette-wheel selection, is a genetic operator used in genetic algorithms for selecting potentially useful solutions for recombination.

With fitness proportionate selection there is a chance some weaker solutions may survive the selection process ; this is an advantage, as though a solution may be weak, it may include some component which could prove useful following the recombination process.

Genetic operators used in genetic algorithms are analogous to those in the natural world: survival of the fittest, or selection ; reproduction ( crossover, also called recombination ); and mutation.

Truncation selection is a selection method used in genetic algorithms to select potential candidate solutions for recombination.

Since each recombination of traits and selection takes a plant generation, to achieve productive and genetically stable perennial crop plants for use by farmers is expected to take several decades.

Besides natural selection other factors like recombination and mutation rate can also determine SNP density.

The level of linkage disequilibrium is influenced by a number of factors, including genetic linkage, selection, the rate of recombination, the rate of mutation, genetic drift, non-random mating, and population structure.

An evolutionary algorithm ( EA ) is a heuristic optimization algorithm using techniques inspired by mechanisms from organic evolution such as mutation, recombination, and natural selection to find an optimal configuration for a specific system within specific constraints.

Genetic algorithms use biologically-derived techniques such as inheritance, mutation, natural selection, and recombination.

He also held up Theodosius Dobzhansky as a counterexample to Johnson's assertion that naturalism undergirds Darwinism and criticized Johnson's decision to include recombination as a form of mutation and his assessment of sexual selection as a relatively minor component of Darwinian theory in the late twentieth century.

Clonal selection algorithms are most commonly applied to optimization and pattern recognition domains, some of which resemble parallel hill climbing and the genetic algorithm without the recombination operator.