Question: What is the rate of recombination?
About the article "Evolution", section "Genetic hitchhiking".

Candidate passages:
Another reaction that can sometimes occur instead of disproportionation is recombination.
During recombination, two radicals form one new non-radical product and one new bond.
Similar to disproportionation, the recombination reaction is exothermic and requires little to no activation energy.
The ratio of the rates of disproportionation to recombination is referred to as kD/kC and often favors recombination compared with disproportionation for alkyl radicals.
As the number of transferable hydrogens increase, the rate constant for disproportionation increases relative to the rate constant for recombination. 
PRDM9 is thought to mediate the process of meiotic homologous recombination. 
Given a set of four or more sampled haploid chromosomes, the four-gamete test (FGT) detects recombination events by locating pairs of segregating sites that cannot have arisen without either recombination or a repeat mutation.
Under the infinite-sites assumption (i.e.
repeat mutations have zero probability), the probability of a repeat mutation is zero, and hence a recombination event is inferred.
For example, if the data being studied consists of bi-allelic single-nucleotide polymorphism data, then the following configuration could be generated "without" recombination.
However, the following configuration cannot be generated without recombination.
The FGT detects calls a recombination event if the above configuration in occurs in the data.
The data in the above configuration is considered to be "incompatible" with any non-recombining ancestral history.
The FGT has low statistical power to detect recombination.
Furthermore, the FGT is suitable only when the mutation rate is significantly smaller than the recombination rate.
If the mutation rate is high, then the infinite-sites assumption is violated.
For example, the FGT is generally suitable for human datasets, but is unsuitable for bacterial datasets. 
While recombination of chromosomes is an essential process during meiosis, there is a large range of frequency of cross overs across organisms and within species.
Sexually dimorphic rates of recombination are termed heterochiasmy, and is observed more often than a common rate between male and females.
In mammals, females often have a higher rate of recombination compared to males.
It is theorized that there are unique selections acting or meiotic drivers which influence the difference in rates.
The difference in rates may also reflect the vastly different environments and conditions of meiosis in oogenesis and spermatogensis. 
In genetic engineering, recombination can also refer to artificial and deliberate recombination of disparate pieces of DNA, often from different organisms, creating what is called recombinant DNA.
A prime example of such a use of genetic recombination is gene targeting, which can be used to add, delete or otherwise change an organism's genes.
This technique is important to biomedical researchers as it allows them to study the effects of specific genes.
Techniques based on genetic recombination are also applied in protein engineering to develop new proteins of biological interest.