- Viral evolution
Viral evolution is a subfield of
evolutionary biologythat is specifically concerned with the evolutionof viruses. Many viruses, in particular RNA viruses, 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
epidemiologyof viral diseases such as influenza, HIV, and hepatitis. It also causes problems in the development of successful vaccines and antiviraldrugs, as resistant mutations 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, evolutionof a viruswhile 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 antiviraldrug while the host (patient) takes it, but rapidly revert to wild-typeif treatment ceases.
Changes may include
point mutationsor epistatic mutations, as well as genome rearrangementsto genesand other functional gene sequencessuch as gene acquisition, gene creationand gene deletion as well as recombination and translocation events.
* 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.
Wikimedia Foundation. 2010.
Look at other dictionaries:
Viral quasispecies — A viral quasispecies is a group of viruses related by a similar mutation or mutations, competing within a highly mutagenic environment. The theory predicts that a viral quasispecies at a low but evolutionarily neutral and highly connected (that… … Wikipedia
Viral marketing — Viral marketing, viral advertising, or marketing buzz are buzzwords referring to marketing techniques that use pre existing social networks to produce increases in brand awareness or to achieve other marketing objectives (such as product sales)… … Wikipedia
Viral eukaryogenesis — is the hypothesis that the cell nucleus of eukaryotic life forms evolved from a large DNA virus in a form of endosymbiosis within an archaea cell. It was proposed by Philip Bell in 2001, and gained support as large complex DNA viruses capable of… … Wikipedia
Evolution of sexual reproduction — The evolution of sexual reproduction is currently described by several competing scientific hypotheses. All sexually reproducing organisms derive from a common ancestor which was a single celled eukaryotic species. Many protists reproduce… … Wikipedia
Evolution (Dove) — Infobox TV advert name=Evolution caption=Promotional image for Evolution client=Unilever product=Dove Campaign for Real Beauty agency=Ogilvy Mather (Toronto) director=Yael Staav Tim Piper production company=Reginald Pike producer= music=The… … Wikipedia
Viral — Virus Pour les articles homonymes, voir Virus (homonymie) … Wikipédia en Français
Viral video — A viral video is a video clip that gains widespread popularity through the process of Internet sharing, typically through email or IM messages, blogs and other media sharing websites. Viral videos are often humorous in nature and include… … Wikipedia
Viral art — According to the author Malcolm Miles, [Miles, M. (2001). Viral Art – Strategies For a New Democracy. Journal of Visual Art Practices, Vol. 1 (2), pp 71 79.] viral art originated as a contemporary visual art practice, which used shock tactics to… … Wikipedia
Dragonball Evolution — Theatrical release poster Directed by James Wong Produced by … Wikipedia
Eucariogénesis viral — Saltar a navegación, búsqueda La eucariogénesis viral es una hipótesis que sostiene que el núcleo de la célula eucariota evolucionó de un gran virus ADN mediante endosimbiosis dentro una célula de arquea. Fue propuesta en 2001 por Philip Bell y… … Wikipedia Español