But with natural modification what scientists call mutation the virus adapted itself to stick to human body cells which marked the beginning of the mayhem in wuhan. Presence of an effective antiviral drug presence of strong immunity in the population etc.
When the population size is large selection will be predominant and random drift less common.
Virus mutation for dummies. This elevated mutation rate when combined with natural selection allows viruses to quickly adapt to changes in their host environment. Sars cov 2 is an rna virus. Virus mutations create genetic diversity which is subject to the opposing actions of selection and random genetic drift both of which are directly affected by the size of the virus population.
The viral dna and proteins the host cell made are then assembled into more viruses. The host cell bursts or the virus transports itself out of the cell which allows it to spread to neighboring cells. 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.
Examples of dna viruses are herpes and various poxviruses. In addition most viruses provide many offspring so any mutated genes can be passed on to many offspring quickly. These phenomena occur when the virus encounters radically changing conditions of infection e g.
We will explore how viruses evolve within a host during transmission to novel susceptible hosts and establish infections in new host species. For a consensus sequence to change a mutation or group of mutations must become preponderant as a result of a selective advantage that makes the mutated strain preponderant.
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