Viral evolution
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2008-03-31T03:07:25Z
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/* Further reading */ added [[Category:Microbiology]]
'''Viral evolution''' is a subfield of [[evolutionary biology]] that is specifically concerned with the [[evolution]] of [[virus]]es. Many [[virus]]es, in particular [[RNA virus]]es, have short generation times and relatively high mutation rates (on the order of one point mutation or more per genome per round of replication for RNA viruses). This elevated mutation rate, when combined with [[natural selection]], allows viruses to quickly adapt to changes in their host environment.
Viral evolution is an important aspect of the [[epidemiology]] of viral diseases such as [[influenza]], [[HIV]], and [[hepatitis]]. It also causes problems in the development of successful [[vaccine]]s and [[antiviral]] [[medication|drugs]], as [[Resistance to antiviral drugs|resistant mutation]]s often appear within weeks or months after the beginning of the treatment.
RNA viruses are also used as a model system to study evolution in the laboratory.
One of the main theoretical models to study viral evolution is the [[quasispecies model]], as the [[viral quasispecies]].
==Inter-host and Intra-host evolution==
In evolutionary virology and to an extent in the wider field of [[pathology]], inter-host evolution is considered to represent the geological, i.e. visible or detectable, [[evolution]] of a [[virus]] while intra-host evolution represents the invisible evolution of a virus. Adaptive changes acquired by inter-host evolution are rarely lost once acquired. Changes acquired by intra-host evolution may be lost if the evolutionary landscape changes, for example: a population of viruses may become resistant to an [[antiviral]] drug while the host (patient) takes it, but rapidly revert to [[wild-type]] if treatment ceases.
Changes may include [[point mutations]] or [[Epistasis|epistatic]] mutations, as well as [[genome rearrangements]] to [[genes]] and other [[functional gene sequences]] such as [[gene acquisition]], [[gene creation]] and [[Genetic deletion|gene deletion]] as well as [[Genetic recombination|recombination]] and [[Chromosomal translocation|translocation]] events.
==See also==
*[[Viral classification]]
*[[RNA virus]]
*[[DNA virus]]
*[[Viral quasispecies]]
==Further reading==
* E. Domingo and C.K. Biebricher and M. Eigen and J.J. Holland (2002). ''Quasispecies and RNA Virus Evolution: Principles and Consequences.'' Landes Bioscience.
* S.F. Elena and [[R. E. Lenski]] (2003). Evolution experiments with microorganisms: the dynamics and genetic bases of adaptation. ''Nat. Rev. Genet.'' '''4:'''457-469.
[[Category:Evolutionary biology]]
[[Category:Virology]]
[[Category:Microbial population biology]]
[[Category:Evolution]]
[[Category:Microbiology]]
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[[ja:ウイルス進化説]]