Viral evolution

Subfield of evolutionary biology and virology concerned with the evolution of viruses

Viral evolution is a subfield of evolutionary biology and virology concerned with the evolution of viruses. 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). Although most viral mutations confer no benefit and often even prove deleterious to viruses, the rapid rate of viral mutation combined with natural selection allows viruses to quickly adapt to changes in their host environment.

From Wikipedia, under CC BY-SA. More on occurri.