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Viral evolution is a subfield of evolutionary biology and virology that is specifically concerned with the evolution of viruses. [1] [2] Viruses have short generation times, and many—in particular RNA viruses—have relatively high mutation rates (on the order of one point mutation or more per genome per round of replication).
New groups of viruses might have repeatedly emerged at all stages of the evolution of life. [16] There are three major theories about the origins of viruses: [16] [17] Regressive theory Viruses may have once been small cells that parasitised larger cells. Eventually, the genes they no longer needed for a parasitic way of life were lost.
The viral eukaryogenesis hypothesis points to the cell cycle of eukaryotes, particularly sex and meiosis, as evidence. [6] Little is known about the origins of DNA or reproduction in prokaryotic or eukaryotic cells. It is thus possible that viruses were involved in the creation of Earth's first cells. [8]
The origins of the virus responsible for Covid-19 have been “unambiguously” traced to horseshoe bats, according to a new study. ... The study is published in Genome Biology and Evolution. Show ...
Viruses may even have multiple origins and different types of viruses may have evolved independently over the history of life. [52] There are different hypotheses for the origins of viruses, for instance an early viral origin from the RNA world or a later viral origin from selfish DNA. [52]
[13]: 810 Once called "jumping genes", transposons are examples of mobile genetic elements and could be the origin of some viruses. They were discovered in maize by Barbara McClintock in 1950. [28] This is sometimes called the "vagrancy hypothesis", [6]: 16 [26]: 11–12 or the "escape hypothesis". [27]: 24 Co-evolution hypothesis
Viral phylodynamics is the study of how epidemiological, immunological, and evolutionary processes act and potentially interact to shape viral phylogenies. [1] Since the term was coined in 2004, research on viral phylodynamics has focused on transmission dynamics in an effort to shed light on how these dynamics impact viral genetic variation.
A founder virus can introduce a different phenotype for the ensuing evolution. Evolution of viruses in nature and as disease agents can be viewed as succession of mutant spectrum alterations, subjected to expansions and reductions of population size in a continuous interplay of positive and negative selection and random drift.