Every time a genome is replicated, there’s a chance that an error will be introduced. This is true for all life forms. On a small scale, these mutations can lead to genetic diseases or cancers. On a much larger scale, random mutations are an important tool of evolution.
During the COVID-19 pandemic, the SARS-CoV-2 virus has picked up many mutations as it spread around the world. Most of these mutations have been inconsequential – the virus didn’t change in any significant way. Others have given rise to variants such as B.1.1.7 and B.1.351, which present complications for public health efforts. By studying the evolution of the virus, we can monitor how it’s spreading and predict the characteristics of variants as they are detected.