Dödligt virus från Kina orsakar panik (SARS-CoV-2, COVID-19)

"Since this is an RNA virus, it will continue to mutate as long as it continues to circulate in humans. Additional mutations as the virus adapts to the human host may make the virus less severe or more severe, or less or more efficient in spreading. It’s too early to tell what will happen, which is why ongoing surveillance by sequencing virus genomes is so important."

However, their mutation rates are almost disastrously high, and a small increase in mutation rate can cause RNA viruses to go locally extinct. Researchers often assume that natural selection has optimized the mutation rate of RNA viruses, but new data shows that, in poliovirus, selection for faster replication is stronger and faster polymerases make more mistakes.
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Many mutations cause organisms to leave fewer descendants over time, so the action of natural selection on these mutations is to purge them from the population. While a small percentage of mutations are helpful and some are inconsequential (neutral or nearly neutral in effect), a large portion of mutations are harmful